Note that the nm/kev relationship is inverse because wavelength and energy are inversely related.

Size: px
Start display at page:

Download "Note that the nm/kev relationship is inverse because wavelength and energy are inversely related."

Transcription

1 4 X-ray Spectroscopy 4.1 What are X rays? X rays are electromagnetic radiation: another region in the spectrum, along with ultraviolet, infrared, visible etc. They are characterised by very short wavelengths, meaning high frequencies and high energies. The wavelength range of the X ray region is 0.01 to 10 nm, compared to nm for the visible region. This makes X ray photons up to times more energetic than visible radiation. There are two other units commonly used in reference to X rays: another wavelength unit, the Angstrom (Å) and the electron volt, a measure of energy (expressed as kev). Their relationship is shown in Eqn Å = 1 nm = 1.24 kev Eqn 4.1 Note that the nm/kev relationship is inverse because wavelength and energy are inversely related. X rays are produced in three ways: 1. when high energy electrons collide with a surface, and are slowed down by the collision; the loss of energy produces a continuous band of X ray wavelengths 2. emissions from decaying radioactive nuclei 3. emission of X rays from matter which has been irradiated with a X ray beam; the emitted X rays are single wavelengths, and of different energies to the excitation beam Processes 1 & 2 are employed in X ray sources, while process 3 produces fluorescent radiation, exploited in the important analytical technique, X ray fluorescence, which this chapter concentrates on. 4.2 Dangers associated with X ray use The high energies associated X rays mean that they are potentially harmful to living organisms, because of the chance that the energy will be absorbed by molecules in the organism. This can cause destruction or alteration to the molecules absorbing the energy. The damage may be direct the photon breaks bonds in an important molecule, or indirect the photon splits water, forming the very reactive hydroxyl radical, which then reacts with an important biochemical substance. If the species affected is genetic material, i.e. DNA, then the chance exists for mutated cells to be produced, leading to the formation of cancers. The effect is cumulative: this is why there is a limited number of body X rays that a person can have with in a set period of time. Too many increases the number of damaged molecules and therefore, the chance of serious health consequences. There are a number of ways that limit the possible dangers associated with X ray use: instruments using them are thoroughly sealed (usually with lead) so that no radiation should escape the seals are checked on a regular basis where the instrument has removable panels which can, if opened, allow the X rays to escape, then microswitches are employed which will trip out the X ray source within milliseconds, eliminating substantial risk of accidental exposure operators of X ray instruments wear radiation badges which are developed each month to check the levels of exposure

2 4.3 X ray spectroscopic techniques X rays are used analytically in three different techniques: X ray fluorescence (XRF) where the emission of characteristic wavelength X rays from matter irradiated by an X ray beam is used to identify and quantify particular elements X ray diffraction (XRD) where X rays are deflected through characteristic angles (diffracted) by the crystal structure of the matter; this can be used for spectral fingerprinting, especially of minerals X ray absorption (XRA) which is the familiar use of X rays to laypersons in medicine and materials testing, where the varying density of matter causes variation in the absorption of the X ray beam. Bones are denser than tissue and absorb more radiation, hence giving high absorption, while defects (holes) in a metal component are picked by a X ray absorption scan because the X rays pass unabsorbed through them Only XRF most useful for chemical analysis will be examined in this course. 4.4 X ray fluorescence As you might expect from the name, X ray fluorescence is a emission technique, where the radiation measured from the sample is of different (and higher) wavelengths than the incident radiation. A little bit of history (non examinable) The 1895 discovery of X rays by Wilhelm Roentgen was also the discovery of X ray fluorescence, though Roentgen did not do anything with this aspect of his work. In 1913, Henry Mosley showed that the generated X rays were characteristic of particular elements, and that the wavelengths were related to atomic number. It was this discovery by Mosley that caused the re ordering of the elements in the periodic table away from atomic mass, and removed some of the anomalies in Mendeleev s table. In the following decade, a number of physicists, including Mosley and the Bragg brothers, struggled to design equipment that could efficiently generate fluorescent X rays, using electron beams as excitation. In 1928, Glocker and Schreiber showed that using a beam of X rays to excite fluorescence was a better way and actually carried out quantitative analysis of real samples. However, this discovery did not lead to immediate developments because of problems in separating different wavelengths (monochromation) and detecting the radiation. In 1948, Friedman and Birks took some of the components of an X ray diffraction instrument and built the first XRF spectrometer as would be recognised today. The first commercial instruments were released in the 1950s, and the next two decades were dominated by improvements in detection systems, particularly the silicon drift semiconductor detector discovered in Generation of fluorescent X rays As with other forms of spectroscopy that you are familiar with eg UV/VIS, AAS, flame emission XRF deals with the electrons. In those other spectroscopic techniques, the electrons were simply moved up and down in their orbitals, whereas in XRF, electrons are actually ejected from the atom. A second difference is that in XRF it is the inner shell electrons that are affected, whereas in the others, it is those in the outer shell. The emitted radiation is produced after an inner shell electron (most commonly from one of the first two shells the old symbols K&L tend to be used rather than 1st and 2nd orbitals in an atom) is ejected entirely from the atom by incident X rays (Figure 4.1(a)). AIT 4.2

3 This creates a "hole" in the electron shells, which is filled by electrons in higher shells. A cascade effect can occur since an electron dropping down a level to fill a hole creates a hole which in turn, is filed from a higher shell again (Figure 4.1(b)). Since the electrons are moving to lower energy levels, they lose the excess energy in the form of radiation (Figure 4.1(c)). M shell L shell M & L electrons drop down X ray K electron ejected X rays emitted K shell (a) (b) (c) FIGURE 4.1 Electron transitions involved in X ray fluorescence The transitions in XRF are given labels which identify them when a spectrum is recorded. The labels indicate: the shell from which the electron was ejected K or L, very rarely M the shell from which the filling electron came the Greek letters,, and indicate that the filling electron came from 1, 2 or 3 shells respectively, from the hole Transitions from KL, MK, ML and NL shells produce radiation of X ray energy for most elements (except the very light ones). CLASS EXERCISE 4.1 (a) What are the two transitions shown in Figure 4.1? (b) Draw the transitions corresponding to the labels K and L. N M L K AIT 4.3

4 Why are these labels important? There are important trends in wavelength and intensity that can be followed for these transitions (shown in Table 4.1), which can help identify the presence of species in a sample, and also are a shorthand way of referring to certain characteristic emissions. TABLE 4.1 Energy and intensity trends for X ray fluorescent photons Trend Behaviour Energy for a given element Intensity for a given element K > K >> L > L K > K >> L > L Energy for a given transition Increases with increasing atomic number (see Figure 4.2 & Table 4.2) CLASS EXERCISE 4.2 Explain the order of energies for the four transitions. TABLE 4.2 Energies (kev) of selected element XRF lines Element K K L L Ca Cr Fe Sn Pb K 60 kev L Atomic Number FIGURE 4.2 Energies of K and L transitions vs atomic number AIT 4.4

5 Given that the K line is the most intense for each element, there might seem to be little use for the other lines. Qualitatively they help in making a definite identification, but they also have use quantitatively because for reasons of excitation and detection, there are limits on which elements can be analysed by their K line. This is covered in more detail later. 4.5 XRF instrumentation There are two basic designs of XRF instruments, mainly due to the development of the wavelength selective semiconductor detectors described above. These two instrument types are known as: wavelength dispersive the older type, using a conventional monochromator based design to separate the fluorescent wavelengths (Figure 4.3) energy dispersive uses a special detector which doesn't require a monochromator (Figure 4.4) sample holder emitted radiation single excitation X-rays many s detector path X-ray source collimator dispersing crystal detector FIGURE 4.3 Schematic diagram of a wavelength dispersive XRF instrument (with moving detector) The wavelength dispersive instrument uses a monochromator where the emitted wavelengths are diffracted by a crystal at different angles. Conventional spectroscopic instruments, such as UV VIS spectrophotometers, are designed so that the diffraction medium rotates and one wavelength at a time leaves the exit slit. In XRF instruments which are designed for high resolution work, both the diffracting crystal and the detector unit move around a circular track (known as a goniometer), picking up one wavelength after another. ICP emission instruments also use this design. FIGURE 4.4 Schematic diagram of a energy dispersive XRF instrument AIT 4.5

6 The energy dispersive instrument has a key component that makes it very different to the older wavelength dispersive design: its semiconductor detector has the unique ability to be able to distinguish between photons of different energy withoutt the need for physical separation. It is thus a single detector multichannel instrument, with the advantages that such a configuration brings: simplicity speed cost size Energy dispersive instruments can be small benchtop designs, or even hand held battery powered 4.5). They are not XRF devices, capable of being used in the field or in the factory (as shown in Figure as accurate as a laboratory device, but have obvious convenience advantages (think about an ion items selectivee electrode vs a HPLC for measuring nitrate). They can also be used to analyse large which cannot be fitted into a conventional instrument. Examples of this include valuable works of art and ancient artefacts unearthed in archaeological excavations (see Figure 4.6). However, wavelength dispersive instruments are still important because they are more sensitive and have better resolution than energy dispersives. The best XRF instruments in terms of absolute performance remain wavelength dispersive, and can cost in excess of $300,000! Radiation source The X ray tube consists of a heated wire cathode, which emits electrons. They are accelerated towards to the anode a block of metal knownn as the target and the collision releases energy in the form of a continuous spectrum of X rays. A schematic diagram of the tube is shown in Figure 4. 7 below. The tube is evacuated to avoid complications caused by ionisation of gas molecules. FIGURE 4.5 Portable energy dispersive XRF instrument (courtesy of InnovXsys) FIGURE 4.6 Portable energy dispersive XRF instrument used to analyse a religious painting in position (Kriznar et al, 9th International Conference on NDT of Art) AIT 4.6

7 window X-rays target electrons cathode FIGURE 4.7 Schematic diagram of an X ray tube There are three variables that affect the output of an X ray tube (as shown in Figure 4.8): applied voltage between the electrodes current the material used on the surface of the target exposed to the electron beam. Target anodes are made from a block of copper, with a coating of another metal on the surface which takes the electron impact. The block is water cooled to remove the heat which accumulates as part of the collision process. Metals commonly employed as the contact surface are rhodium, tungsten and molybdenum. Heavier elements generate more radiation, as can be seen in Figure 4.8(c). FIGURE 4.8 Effect on X ray tube output of (a) tube current (b) applied potential and (c) target element (from Bertin, Introduction To X ray Spectrometric Analysis, Plenum). AIT 4.7

8 CLASS EXERCISE 4.3 Complete the table below, to summarise Figure 4.8. Tube Variable Wavelength Range Intensity Voltage Current Target element The continuous spectrum shown in Figure 4.8 is not quite accurate, as the real output has two or more peaks superimposed. These are due to X ray fluorescence processes occurring in the atoms of the target. These may cause an interference in XRF that must be allowed for or removed, or can be used as a monochromatic source of X rays, if appropriate filtering is available, as occurs in XRD. Rhodium, for example, the target metal in the XRF instrument in this department, emits lines at 2.7, 2.8, 3.0, 20.2 & 22.7 kev. The only option for many years to the X ray tube was a radioactive source, which generated a range of X ray wavelengths, without the need for electrical power. However, the problems of radioactive sources and the lower output intensities reduced the usability of these sources. Traditionally, X ray tubes require large quantities of electrical power: typical operating conditions may be 35kV and 30 ma (1.05 kw), necessitating connection to the mains power supply. Low current X ray tubes ( ua) have been recently developed which have allowed batterypowered portable devices for field analysis and small desktop instruments, such as the Minipal we have. CLASS EXERCISE 4.4 What would be the main disadvantage of these low current X tubes? Voltage is the most important variable in X ray fluorescence because it is determines the energy of the exciting photons, and therefore which elements will be excited. The kev unit for X ray energy is related to the voltage needed to excite a particular element line. An electron accelerated towards a positive electrode with a voltage equal to that kev value (in kv) has the energy contained in that X ray. To excite the element that generates that fluorescent X ray typically requires a tube voltage twice the kev value. EXAMPLE 4.1 The K line of calcium has an energy of 3.69 kev. What tube voltage needed to excite this line? 2 x 3.69 = 5.38 kv. AIT 4.8

9 CLASS EXERCISE 4.5 The X ray tube in our instrument has a maximum voltage of 30kV. What is the maximum atomic number for an element that can have its K line excited (see Figure 4.2)? Detectors There are three common X ray detectors: semiconductor gas filled/flow/proportional scintillation Semiconductor detectors are used in energy dispersive devices, while the other two are used together in wavelength dispersive instruments. The reason that two detectors are required in WD instruments is that neither covers the full range of X rays. Their mechanism of operation is described below. SEMICONDUCTORS The most recent development in X ray detection is the silicon drift detector (using semiconductor technology). The precise means by which X rays are detected by such a device are beyond the scope of this course. The most important aspect of this detector is its ability to produce an output (a current pulse) that is proportional to the energy of the incoming photon. It can do this for polychromatic radiation equally well, when linked with pulse height counting equipment. This sums the number of pulses of each amount of current (e.g. 1, 1.1, 1.2 ua) and so the final spectrum is really a plot of number of pulses vs current. A correlation between energy and current must be made by some internal setting in the detector, eg a current pulse of 1.2 ua is created by a photon of 2.5 kev energy. This unique ability means that energy dispersive instruments do not need a monochromator with the all the multi channel type advantages that brings. The two major limitations are: resolution the ability to distinguish between photons of similar but not identical energy is not perfect sensitivity there is a maximum count rate (in our instrument, it is 60,000 per second) above which the detector is overloaded It is not clear why similar detectors have not been developed in other regions of the electromagnetic spectrum, especially the UV VIS where so many instruments operate. PROPORTIONAL (OR FLOW) COUNTERS X rays have sufficient energy to ionise atoms. This ability is exploited in a number of detectors, which use a chamber filled with an inert gas, such as argon, and electrical plates which collect the ions that are produced. The chain reaction may generate hundreds of electrons and ions from the one photon. The degree to which the chain reaction proceeds depends on the applied voltage between the collector plates and the energy of the photons. The most commonly used voltage range is V, where the response of the detector is approximately linear which voltage. This region is known as the proportional region, and a detector using this behaviour as a proportional counter. AIT 4.9

10 A typical proportional counter is shown below in Figure A small flow of gas is normally passed through the detector to keep it at a constant pressure. The gas is 90% argon/10% methane. These detectors are also known as flow counters. Proportional counters are most suited to X ray photons from Å (because these detectors are used in WD instruments, wavelength is the usual unit), which in terms of X ray fluorescence, come from the lighter elements. X-rays gas in anode FIGURE 4.9 Schematic diagram of a proportional flow counter cathode SCINTILLATION COUNTERS The term 'scintillation' means the generation of multiple photons of visible light from matter, which has absorbed a higher energy photon, e.g. an X ray. Certain crystalline substances possess this property. The most widely used scintillation crystal is sodium iodide, which has been doped (contaminated) with a about 0.2% thallium iodide. Some organic substances, often in solution, are also used. Each X ray photon that enters the scintillation chamber can produce thousands of visible wavelength photons. These are measured by a conventional photomultiplier tube. Scintillation counters are best used for shorter wavelength X rays, from heavier elements, and so complement proportional counters in their range of operation. Figure 4.10 shows the ranges available from each type of detector. Where they overlap, neither works perfectly, and unfortunately, this is the region in XRF where the commercially important metals such as iron, chromium and manganese produce lines. Å() Scintillation Flow FIGURE 4.10 Detector ranges AIT 4.10

11 4.6 Qualitative analysis XRF is an ideal qualitative technique for elements above sodium, because of its limited sample preparation. Solids are in fact more easily analysed than solutions. Granular solids need only be ground into a powder, while fixed shape materials only require a polish. The technique is non destructive which means that valuable samples can be analysed without risk of damage. This allied with the portability of an energy dispersive instrument means that works of art and archaeological items can be scanned in situ. Emission lines (weak and strong) for elements are well known, and it is easy to identify the components of a mixture. The rules of intensity trends for the various lines must be followed (Table 4.1). If a line which corresponds to the K emission of a particular element is found, then the K line must also be present, and at about 20 40% of the intensity of the K line. XRF is a surface technique: only the top 100 um (or so) of the sample is analysed. Therefore, for a true overall picture of the sample, it must be made homogenous. However, for a sample with intentional layers, e.g. chrome plated steel, only the surface would be analysed, whereas a technique which relied on solution or powder samples, would require that the coating layer be separated. It is not the most sensitive technique, but the newer instruments are able to detect much lower concentrations than before. Typically it will be able to detect concentrations of 10 mg/kg for elements with K lines present, and about ten times this for those with only L lines sufficiently well for qualitative purposes. The technique does not discriminate at all between different forms of the same elements. Iron gives exactly the same set of wavelengths, regardless of whether it is in steel, iron ore, aqueous solution or an ionic salt. Figure 4.11 shows an XRF spectrum, recorded using an energy dispersive instrument, of a dust sample. It illustrates the ability of the technique to identify the presence of a wide range of elements. FIGURE 4.11 XRF spectrum of a dust sample (from Christian & O'Reilly, Instrumental Analysis, Allyn & Bacon) AIT 4.11

12 CASE STUDIES OF SOME UNUSUAL APPLICATIONS FOR XRF 1 The authentication of Victoria Crosses The medals for the highest military honour in Commonwealth countries are made from two melted cannons from the Crimean War (1860s). Because of the value (monetary and emotional) of the medals, they can only be analysed by a totally non destructive technique. The cannons have a very specific elemental content, and this allows potential forgeries to be identified. Medals in a number of New Zealand collections were analysed, compared with those of known origin in the Australian War Museum and authenticated. The examination of ancient artefacts from an archaeological excavation XRF was used to determine the composition of gold figurines, weapons, paint from wall murals and clay pots excavated on the Greek island of Thera in the remains of the 1500 BC city Akrotiri which was destroyed by a volcanic eruption in similar circumstances to the Roman city of Pompeii. Analysis of the pigments used in a medieval religious painting To assist with future restoration, a large painting from the 15th century in a church in Seville, Spain, was analysed on location by XRF to identify the pigments. 4.7 Quantitative analysis In many respects, quantitative analysis by XRF is the same as other techniques. Standards are prepared, an optimum line (preferably K) chosen to maximise sensitivity and calibration graphs drawn to find the answer. However, XRF is a technique which suffers very severely from matrix interference. As stated above, the iron K peak may occur at exactly the same position, regardless of the matrix, but its intensity will be very different from sample to sample. This is particularly the case when analysing solids, since the matrix is very concentrated. The causes of the interference include: matrix components absorbing the excitation radiation so that the amount of radiation available to excite the analyte is reduced matrix components absorbing the analyte fluorescence particular prominent where elements a few atomic number lower than analyte are present, eg when analysing nickel (atomic number 28) in steel, the high concentration of iron (AN 26) will reduce the Ni K line intensities significantly, compared to a sample of the same concentration of Ni with no iron fluorescence of matrix components, particularly from heavier elements, can cause additional excitation of the analyte, particle size variations, which cause differences in the contact area between sample and incoming X rays and also the scattering of the fluorescent photons To counter the matrix interference, a number of familiar (and not so familiar) techniques have been employed, but by far and away, the most important is matrix matched standards. The normal drawback with this method is the availability of certified reference materials (standards of exactly known composition), but for some of important XRF using sectors (metals, minerals, ceramics) this is not really a problem as such materials are readily available. 1 The complete articles are downloadable from the subject webpage. The details are not examinable but you may be required to give an outline of the study and why XRF was useful. AIT 4.12

13 For the other areas (eg soil) there are the normal methods of dealing with interferences: standard addition the most obvious method, but not as easy to do with solid samples; generally a borax melt (see Sample preparation) will have to be used to ensure homogeneity internal standard not usually employed to deal with matrix interference; in this case, the properties choice is an element ± 2 in atomic number from the analyte scattered X ray standardisation where a wavelength of excitation radiation (eg the Rh line) scattered to the detector is used in the same way as an internal standard There is a new development from one instrument manufacturer Panalytical known as standardless analysis, where a large database of many different types of materials (of known composition) is built into the software. A highly sophisticated mathematical modelling process compensates for interferences by the elements detected in the scan. It is not perfect in terms of accuracy, but the great majority of samples and analytical purposes, it is sufficiently good. 4.8 Practical aspects SAMPLE PREPARATION As mentioned above, variations in particle size can affect intensity. Therefore, all standards and samples need to be in a similar physical form and treated equally. Metals should be cleaned, granular material ground into a fine powder. Powdered material is often pressed into a disc, most requiring some type of binding agent to hold them together. A common method for powdered material is the borax fusion disc, where an approximately 10% mixture of sample in borax (Na2B4O7) is heated to melting (above 1000C) and poured into a metal tray to cool. The effect is to break down the sample matrix to some extent, and provide a more homogeneous mix. It does, however, dilute the sample and reduce line intensities. USE OF HELIUM Lighter elements than calcium require a helium atmosphere for best sensitivity because the low energy photons generated by these elements are absorbed by air. FILTERS These are placed between tube and sample, and absorb a particular range of X rays which would otherwise interfere with the sample spectrum. The tube lines can be removed by this method, but at the expense of a good deal of sensitivity. Trial and error is the best way to determine whether a filter is necessary, and if so, which one. TUBE VOLTAGE & CURRENT CONTROL The importance of tube voltage has been discussed above. With current which only affects intensity, it might be expected that the highest current possible is the best choice. However, this is not the case, as a current that is too high will generate a large broad background bump in the spectrum. This is particularly the case if the sample has high concentrations of light elements. AIT 4.13

14 Revision Questions 1. What procedures are used to ensure the safety of operators of X ray spectrometers? 2. Describe the effect on the output of an X ray tube of (a) current and (b) voltage? 3. How does the spectrum from a X ray tube with a tungsten target differ from that of one with a copper target, assuming the peak intensity is equalised? 4. Why do X ray spectrometers commonly use both flow and scintillation detectors? 5. Draw a diagram showing the transitions occurring that resulting in the production of K and L photons. 6. How do wavelength and energy dispersive XRF instruments differ? 7. Why is XRF such a good qualitative technique? 8. What quantitative technique would you recommend for the analysis of lead containing rocks? Explain your answer. Answers on following page What You Need To Be Able To Do define important terminology explain how X rays are generated outline the health and safety aspects of X ray use distinguish between the three types of X ray spectroscopy describe common X ray sources outline the principles of operation of common X ray detectors draw schematic diagrams and explain the function of each component for typical energy and wavelength dispersive XRF instruments explain the electronic transitions which produce X ray photons by fluorescence describe practical aspects of qualitative analysis by XRF describe practical aspects of quantitative analysis by XRF list advantages and disadvantages of XRF AIT 4.14

15 Answer guide for revision questions Where the answer can be found directly in your notes, a reference to them will be provided. 1. p Figure Different positions of the Ka & Kb lines superimposed on the broad continuous spectrum 4. p Lb Ka 6. Wavelength dispersive: two detectors, moving along circular path; energy dispersive: single detector, no moving parts 7. p Matrix matching impossible, so use of source emission line as internal std possible if intense enough; otherwise std addition or added internal std AIT 4.15

Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy

Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy. Chemistry 311: Instrumentation Analysis Topic 2: Atomic Spectroscopy Topic 2b: X-ray Fluorescence Spectrometry Text: Chapter 12 Rouessac (1 week) 4.0 X-ray Fluorescence Download, read and understand EPA method 6010C ICP-OES Winter 2009 Page 1 Atomic X-ray Spectrometry Fundamental

More information

Chemistry Instrumental Analysis Lecture 19 Chapter 12. Chem 4631

Chemistry Instrumental Analysis Lecture 19 Chapter 12. Chem 4631 Chemistry 4631 Instrumental Analysis Lecture 19 Chapter 12 There are three major techniques used for elemental analysis: Optical spectrometry Mass spectrometry X-ray spectrometry X-ray Techniques include:

More information

1 WHAT IS SPECTROSCOPY?

1 WHAT IS SPECTROSCOPY? 1 WHAT IS SPECTROSCOPY? 1.1 The Nature Of Electromagnetic Radiation Anyone who has been sunburnt will know that light packs a punch: in scientific terms, it contains considerable amounts of energy. All

More information

hν' Φ e - Gamma spectroscopy - Prelab questions 1. What characteristics distinguish x-rays from gamma rays? Is either more intrinsically dangerous?

hν' Φ e - Gamma spectroscopy - Prelab questions 1. What characteristics distinguish x-rays from gamma rays? Is either more intrinsically dangerous? Gamma spectroscopy - Prelab questions 1. What characteristics distinguish x-rays from gamma rays? Is either more intrinsically dangerous? 2. Briefly discuss dead time in a detector. What factors are important

More information

XRF books: Analytical Chemistry, Kellner/Mermet/Otto/etc. 3 rd year XRF Spectroscopy Dr. Alan Ryder (R222, Physical Chemistry) 2 lectures:

XRF books: Analytical Chemistry, Kellner/Mermet/Otto/etc. 3 rd year XRF Spectroscopy Dr. Alan Ryder (R222, Physical Chemistry) 2 lectures: 1 3 rd year XRF Spectroscopy Dr. Alan Ryder (R222, Physical Chemistry) 2 lectures: XRF spectroscopy 1 exam question. Notes on: www.nuigalway.ie/nanoscale/3rdspectroscopy.html XRF books: Analytical Chemistry,

More information

CHEM*3440. X-Ray Energies. Bremsstrahlung Radiation. X-ray Line Spectra. Chemical Instrumentation. X-Ray Spectroscopy. Topic 13

CHEM*3440. X-Ray Energies. Bremsstrahlung Radiation. X-ray Line Spectra. Chemical Instrumentation. X-Ray Spectroscopy. Topic 13 X-Ray Energies very short wavelength radiation 0.1Å to 10 nm (100 Å) CHEM*3440 Chemical Instrumentation Topic 13 X-Ray Spectroscopy Visible - Ultraviolet (UV) - Vacuum UV (VUV) - Extreme UV (XUV) - Soft

More information

Radionuclide Imaging MII Detection of Nuclear Emission

Radionuclide Imaging MII Detection of Nuclear Emission Radionuclide Imaging MII 3073 Detection of Nuclear Emission Nuclear radiation detectors Detectors that are commonly used in nuclear medicine: 1. Gas-filled detectors 2. Scintillation detectors 3. Semiconductor

More information

X-ray spectroscopy: Experimental studies of Moseley s law (K-line x-ray fluorescence) and x-ray material s composition determination

X-ray spectroscopy: Experimental studies of Moseley s law (K-line x-ray fluorescence) and x-ray material s composition determination Uppsala University Department of Physics and Astronomy Laboratory exercise X-ray spectroscopy: Experimental studies of Moseley s law (K-line x-ray fluorescence) and x-ray material s composition determination

More information

MT Electron microscopy Scanning electron microscopy and electron probe microanalysis

MT Electron microscopy Scanning electron microscopy and electron probe microanalysis MT-0.6026 Electron microscopy Scanning electron microscopy and electron probe microanalysis Eero Haimi Research Manager Outline 1. Introduction Basics of scanning electron microscopy (SEM) and electron

More information

Overview of X-Ray Fluorescence Analysis

Overview of X-Ray Fluorescence Analysis Overview of X-Ray Fluorescence Analysis AMPTEK, INC., Bedford, MA 01730 Ph: +1 781 275 2242 Fax: +1 781 275 3470 sales@amptek.com 1 What is X-Ray Fluorescence (XRF)? A physical process: Emission of characteristic

More information

Radioactivity. Lecture 6 Detectors and Instrumentation

Radioactivity. Lecture 6 Detectors and Instrumentation Radioactivity Lecture 6 Detectors and Instrumentation The human organs Neither humans nor animals have an organ for detecting radiation from radioactive decay! We can not hear it, smell it, feel it or

More information

X-RAY SPECTRA. Theory:

X-RAY SPECTRA. Theory: 12 Oct 18 X-ray.1 X-RAY SPECTRA In this experiment, a number of measurements involving x-rays will be made. The spectrum of x-rays emitted from a molybdenum target will be measured, and the experimental

More information

Reference literature. (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters )

Reference literature. (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters ) September 17, 2018 Reference literature (See: CHEM 2470 notes, Module 8 Textbook 6th ed., Chapters 13-14 ) Reference.: https://slideplayer.com/slide/8354408/ Spectroscopy Usual Wavelength Type of Quantum

More information

FXA UNIT G485 Module X-Rays. Candidates should be able to : I = I 0 e -μx

FXA UNIT G485 Module X-Rays. Candidates should be able to : I = I 0 e -μx 1 Candidates should be able to : HISTORY Describe the nature of X-rays. Describe in simple terms how X-rays are produced. X-rays were discovered by Wilhelm Röntgen in 1865, when he found that a fluorescent

More information

Chapter 30 X Rays GOALS. When you have mastered the material in this chapter, you will be able to:

Chapter 30 X Rays GOALS. When you have mastered the material in this chapter, you will be able to: Chapter 30 X Rays GOALS When you have mastered the material in this chapter, you will be able to: Definitions Define each of the following terms, and use it in an operational definition: hard and soft

More information

Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT.

Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT. CHEM 322 Name Exam 3 Spring 2013 Complete the following. Clearly mark your answers. YOU MUST SHOW YOUR WORK TO RECEIVE CREDIT. Warm-up (3 points each). 1. In Raman Spectroscopy, molecules are promoted

More information

X-rays. X-ray Radiography - absorption is a function of Z and density. X-ray crystallography. X-ray spectrometry

X-rays. X-ray Radiography - absorption is a function of Z and density. X-ray crystallography. X-ray spectrometry X-rays Wilhelm K. Roentgen (1845-1923) NP in Physics 1901 X-ray Radiography - absorption is a function of Z and density X-ray crystallography X-ray spectrometry X-rays Cu K α E = 8.05 kev λ = 1.541 Å Interaction

More information

X-Ray Emission and Absorption

X-Ray Emission and Absorption X-Ray Emission and Absorption Author: Mike Nill Alex Bryant February 6, 20 Abstract X-rays were produced by two bench-top diffractometers using a copper target. Various nickel filters were placed in front

More information

SCINTILLATION DETECTORS & GAMMA SPECTROSCOPY: AN INTRODUCTION

SCINTILLATION DETECTORS & GAMMA SPECTROSCOPY: AN INTRODUCTION SCINTILLATION DETECTORS & GAMMA SPECTROSCOPY: AN INTRODUCTION OBJECTIVE The primary objective of this experiment is to use an NaI(Tl) detector, photomultiplier tube and multichannel analyzer software system

More information

Atomic Absorption Spectrophotometry. Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon

Atomic Absorption Spectrophotometry. Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon Atomic Absorption Spectrophotometry Presentation by, Mrs. Sangita J. Chandratre Department of Microbiology M. J. college, Jalgaon Defination In analytical chemistry, Atomic absorption spectroscopy is a

More information

ATOMIC WORLD P.1. ejected photoelectrons. current amplifier. photomultiplier tube (PMT)

ATOMIC WORLD P.1. ejected photoelectrons. current amplifier. photomultiplier tube (PMT) ATOMIC WORLD P. HKAL PAPER I 0 8 The metal Caesium has a work function of.08 ev. Given: Planck constant h = 6.63 0 34 J s, charge of an electron e =.60 0 9 C (a) (i) Calculate the longest wavelength of

More information

4.4.1 Atoms and isotopes The structure of an atom Mass number, atomic number and isotopes. Content

4.4.1 Atoms and isotopes The structure of an atom Mass number, atomic number and isotopes. Content 4.4 Atomic structure Ionising radiation is hazardous but can be very useful. Although radioactivity was discovered over a century ago, it took many nuclear physicists several decades to understand the

More information

GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY

GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY ABSORBED DOSE: The amount of energy absorbed, as a result of radiation passing through a material, per unit mass of material. Measured in rads (1 rad

More information

Spectroscopy. Page 1 of 8 L.Pillay (2012)

Spectroscopy. Page 1 of 8 L.Pillay (2012) Spectroscopy Electromagnetic radiation is widely used in analytical chemistry. The identification and quantification of samples using electromagnetic radiation (light) is called spectroscopy. Light has

More information

X-ray Absorption and Emission Prepared By Jose Hodak for BSAC program 2008

X-ray Absorption and Emission Prepared By Jose Hodak for BSAC program 2008 X-ray Absorption and Emission Prepared By Jose Hodak for BSAC program 2008 1- A bit of History: Wilhelm Conrad Röntgen discovered 1895 the X-rays. 1901 he was honored by the Noble prize for physics. In

More information

The basic structure of an atom is a positively charged nucleus composed of both protons and neutrons surrounded by negatively charged electrons.

The basic structure of an atom is a positively charged nucleus composed of both protons and neutrons surrounded by negatively charged electrons. 4.4 Atomic structure Ionising radiation is hazardous but can be very useful. Although radioactivity was discovered over a century ago, it took many nuclear physicists several decades to understand the

More information

Methods of surface analysis

Methods of surface analysis Methods of surface analysis Nanomaterials characterisation I RNDr. Věra Vodičková, PhD. Surface of solid matter: last monoatomic layer + absorbed monolayer physical properties are effected (crystal lattice

More information

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY student version www.toppr.com Contents (a) Types of Radiation (b) Properties of Radiation (c) Dangers of Radiation (d) Rates of radioactive decay (e) Nuclear

More information

Generation of X-Rays in the SEM specimen

Generation of X-Rays in the SEM specimen Generation of X-Rays in the SEM specimen The electron beam generates X-ray photons in the beam-specimen interaction volume beneath the specimen surface. Some X-ray photons emerging from the specimen have

More information

MS482 Materials Characterization ( 재료분석 ) Lecture Note 4: XRF

MS482 Materials Characterization ( 재료분석 ) Lecture Note 4: XRF 2016 Fall Semester MS482 Materials Characterization ( 재료분석 ) Lecture Note 4: XRF Byungha Shin Dept. of MSE, KAIST 1 Course Information Syllabus 1. Overview of various characterization techniques (1 lecture)

More information

EEE4106Z Radiation Interactions & Detection

EEE4106Z Radiation Interactions & Detection EEE4106Z Radiation Interactions & Detection 2. Radiation Detection Dr. Steve Peterson 5.14 RW James Department of Physics University of Cape Town steve.peterson@uct.ac.za May 06, 2015 EEE4106Z :: Radiation

More information

Chapter Six: X-Rays. 6.1 Discovery of X-rays

Chapter Six: X-Rays. 6.1 Discovery of X-rays Chapter Six: X-Rays 6.1 Discovery of X-rays In late 1895, a German physicist, W. C. Roentgen was working with a cathode ray tube in his laboratory. He was working with tubes similar to our fluorescent

More information

Alpha decay usually occurs in heavy nuclei such as uranium or plutonium, and therefore is a major part of the radioactive fallout from a nuclear

Alpha decay usually occurs in heavy nuclei such as uranium or plutonium, and therefore is a major part of the radioactive fallout from a nuclear Radioactive Decay Radioactivity is the spontaneous disintegration of atomic nuclei. This phenomenon was first reported in 1896 by the French physicist Henri Becquerel. Marie Curie and her husband Pierre

More information

25 Instruments for Optical Spectrometry

25 Instruments for Optical Spectrometry 25 Instruments for Optical Spectrometry 25A INSTRUMENT COMPONENTS (1) source of radiant energy (2) wavelength selector (3) sample container (4) detector (5) signal processor and readout (a) (b) (c) Fig.

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lecture 19 Modern Physics Nuclear Physics Nuclear Reactions Medical Applications Radiation Detectors Chapter 29 http://www.physics.wayne.edu/~alan/2140website/main.htm 1 Lightning

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lightning Review Lecture 19 Modern Physics Nuclear Physics Nuclear Reactions Medical Applications Radiation Detectors Chapter 29 http://www.physics.wayne.edu/~alan/2140website/main.htm

More information

Electron probe microanalysis - Electron microprobe analysis EPMA (EMPA) What s EPMA all about? What can you learn?

Electron probe microanalysis - Electron microprobe analysis EPMA (EMPA) What s EPMA all about? What can you learn? Electron probe microanalysis - Electron microprobe analysis EPMA (EMPA) What s EPMA all about? What can you learn? EPMA - what is it? Precise and accurate quantitative chemical analyses of micron-size

More information

4.4 Atomic structure Notes

4.4 Atomic structure Notes 4.4 Atomic structure Notes Ionising radiation is hazardous but can be very useful. Although radioactivity was discovered over a century ago, it took many nuclear physicists several decades to understand

More information

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY teacher version www.toppr.com Contents (a) Types of Radiation (b) Properties of Radiation (c) Dangers of Radiation (d) Rates of radioactive decay (e) Nuclear

More information

Questions on Instrumental Methods of Analysis

Questions on Instrumental Methods of Analysis Questions on Instrumental Methods of Analysis 1. Which one of the following techniques can be used for the detection in a liquid chromatograph? a. Ultraviolet absorbance or refractive index measurement.

More information

AS 101: Day Lab #2 Summer Spectroscopy

AS 101: Day Lab #2 Summer Spectroscopy Spectroscopy Goals To see light dispersed into its constituent colors To study how temperature, light intensity, and light color are related To see spectral lines from different elements in emission and

More information

X-Rays from Atoms. These are called K α X-rays See table 29.1 for the energy of K α X-rays produced by some elements. Section 29.3

X-Rays from Atoms. These are called K α X-rays See table 29.1 for the energy of K α X-rays produced by some elements. Section 29.3 X-Rays from Atoms The highest photon energy available in a hydrogen atom is in the ultraviolet part of the electromagnetic spectrum Other atoms can emit much more energetic photons larger Z, more electric

More information

An Introduction to Surface Physics for Engineers and Scientists Jorge A. López Gallardo and Miguel Castro Colín

An Introduction to Surface Physics for Engineers and Scientists Jorge A. López Gallardo and Miguel Castro Colín An Introduction to Surface Physics for Engineers and Scientists Jorge A. López Gallardo and Miguel Castro Colín Chapter Two: Basic Processes This chapter will review several physical processes that involve

More information

Because light behaves like a wave, we can describe it in one of two ways by its wavelength or by its frequency.

Because light behaves like a wave, we can describe it in one of two ways by its wavelength or by its frequency. Light We can use different terms to describe light: Color Wavelength Frequency Light is composed of electromagnetic waves that travel through some medium. The properties of the medium determine how light

More information

Spectroscopy: Introduction. Required reading Chapter 18 (pages ) Chapter 20 (pages )

Spectroscopy: Introduction. Required reading Chapter 18 (pages ) Chapter 20 (pages ) Spectroscopy: Introduction Required reading Chapter 18 (pages 378-397) Chapter 20 (pages 424-449) Spectrophotometry is any procedure that uses light to measure chemical concentrations Properties of Light

More information

2 SPECTROSCOPIC ANALYSIS

2 SPECTROSCOPIC ANALYSIS 2 SPECTROSCOPIC ANALYSIS 2.1 Introduction Chemical analysis falls into two basic categories: qualitative what is present quantitative how much is present Spectroscopy is capable of both types of analysis,

More information

How Does It All Work? A Summary of the IDEAS Beamline at the Canadian Light Source

How Does It All Work? A Summary of the IDEAS Beamline at the Canadian Light Source How Does It All Work? A Summary of the IDEAS Beamline at the Canadian Light Source What Makes Up The Canadian Light Source? 4. Storage Ring 5. Synchrotron Light 6. Beamline 1. Electron Gun 2. Linear Accelerator

More information

Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications

Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications Design and Development of a Smartphone Based Visible Spectrophotometer for Analytical Applications Bedanta Kr. Deka, D. Thakuria, H. Bora and S. Banerjee # Department of Physicis, B. Borooah College, Ulubari,

More information

MT Electron microscopy Scanning electron microscopy and electron probe microanalysis

MT Electron microscopy Scanning electron microscopy and electron probe microanalysis MT-0.6026 Electron microscopy Scanning electron microscopy and electron probe microanalysis Eero Haimi Research Manager Outline 1. Introduction Basics of scanning electron microscopy (SEM) and electron

More information

Atomization. In Flame Emission

Atomization. In Flame Emission FLAME SPECTROSCOPY The concentration of an element in a solution is determined by measuring the absorption, emission or fluorescence of electromagnetic by its monatomic particles in gaseous state in the

More information

Elemental analysis by X-ray f luorescence. Sequential benchtop WDXRF spectrometer

Elemental analysis by X-ray f luorescence. Sequential benchtop WDXRF spectrometer Elemental analysis by X-ray f luorescence Sequential benchtop WDXRF spectrometer Elemental analysis is one of the most important fundamental measurements made for industrial quality control and research

More information

EMISSION SPECTROSCOPY

EMISSION SPECTROSCOPY IFM The Department of Physics, Chemistry and Biology LAB 57 EMISSION SPECTROSCOPY NAME PERSONAL NUMBER DATE APPROVED I. OBJECTIVES - Understand the principle of atomic emission spectra. - Know how to acquire

More information

Nuclear Decays. Alpha Decay

Nuclear Decays. Alpha Decay Nuclear Decays The first evidence of radioactivity was a photographic plate, wrapped in black paper and placed under a piece of uranium salt by Henri Becquerel on February 26, 1896. Like many events in

More information

Understanding X-rays: The electromagnetic spectrum

Understanding X-rays: The electromagnetic spectrum Understanding X-rays: The electromagnetic spectrum 1 ULa 13.61 kev 0.09 nm BeKa 0.11 kev 11.27 nm E = hn = h c l where, E : energy, h : Planck's constant, n : frequency c : speed of light in vacuum, l

More information

Laboratory Manual 1.0.6

Laboratory Manual 1.0.6 Laboratory Manual 1.0.6 Background What is X-ray Diffraction? X-rays scatter off of electrons, in a process of absorption and re-admission. Diffraction is the accumulative result of the x-ray scattering

More information

Sample Examination Questions

Sample Examination Questions Sample Examination Questions Contents NB. Material covered by the AS papers may also appear in A2 papers. Question Question type Question focus number (section A or B) 1 A Ideal transformer 2 A Induced

More information

Diffractometer. Geometry Optics Detectors

Diffractometer. Geometry Optics Detectors Diffractometer Geometry Optics Detectors Diffractometers Debye Scherrer Camera V.K. Pecharsky and P.Y. Zavalij Fundamentals of Powder Diffraction and Structural Characterization of Materials. Diffractometers

More information

X-RAY SCATTERING AND MOSELEY S LAW. OBJECTIVE: To investigate Moseley s law using X-ray absorption and to observe X- ray scattering.

X-RAY SCATTERING AND MOSELEY S LAW. OBJECTIVE: To investigate Moseley s law using X-ray absorption and to observe X- ray scattering. X-RAY SCATTERING AND MOSELEY S LAW OBJECTIVE: To investigate Moseley s law using X-ray absorption and to observe X- ray scattering. READING: Krane, Section 8.5. BACKGROUND: In 1913, Henry Moseley measured

More information

CHAPTER A2 LASER DESORPTION IONIZATION AND MALDI

CHAPTER A2 LASER DESORPTION IONIZATION AND MALDI Back to Basics Section A: Ionization Processes CHAPTER A2 LASER DESORPTION IONIZATION AND MALDI TABLE OF CONTENTS Quick Guide...27 Summary...29 The Ionization Process...31 Other Considerations on Laser

More information

Atomic Structure and Radioactivity

Atomic Structure and Radioactivity Atomic Structure and Radioactivity Models of the atom know: Plum pudding model of the atom and Rutherford and Marsden s alpha experiments, being able to explain why the evidence from the scattering experiment

More information

What happens during nuclear decay? During nuclear decay, atoms of one element can change into atoms of a different element altogether.

What happens during nuclear decay? During nuclear decay, atoms of one element can change into atoms of a different element altogether. When Henri Becquerel placed uranium salts on a photographic plate and then developed the plate, he found a foggy image. The image was caused by rays that had not been observed before. For his discovery

More information

Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002

Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002 Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002 More Quantum Physics We know now how to detect light (or photons) One possibility to detect

More information

Analytical Technologies in Biotechnology Prof. Dr. Ashwani K. Sharma Department of Biotechnology Indian Institute of Technology, Roorkee

Analytical Technologies in Biotechnology Prof. Dr. Ashwani K. Sharma Department of Biotechnology Indian Institute of Technology, Roorkee Analytical Technologies in Biotechnology Prof. Dr. Ashwani K. Sharma Department of Biotechnology Indian Institute of Technology, Roorkee Module - 2 Radioisotopes Techniques Lecture - 3 GM Counting and

More information

Chapter 7 - Radioactivity. Science 10 P

Chapter 7 - Radioactivity. Science 10 P Chapter 7 - Radioactivity Science 10 P286-328 What is Radiation? Radiation is: anything that radiates away from something. Radiation may be in the form of: particles (neutrons, alpha particles, and beta

More information

Emphasis on what happens to emitted particle (if no nuclear reaction and MEDIUM (i.e., atomic effects)

Emphasis on what happens to emitted particle (if no nuclear reaction and MEDIUM (i.e., atomic effects) LECTURE 5: INTERACTION OF RADIATION WITH MATTER All radiation is detected through its interaction with matter! INTRODUCTION: What happens when radiation passes through matter? Emphasis on what happens

More information

Ba (Z = 56) W (Z = 74) preferred target Mo (Z = 42) Pb (Z = 82) Pd (Z = 64)

Ba (Z = 56) W (Z = 74) preferred target Mo (Z = 42) Pb (Z = 82) Pd (Z = 64) Produced by accelerating electrons with high voltage and allowing them to collide with metal target (anode), e.g, Tungsten. Three Events (Two types of x-ray) a) Heat X-Ray Tube b) bremsstrahlung (braking

More information

Core Questions Physics unit 4 - Atomic Structure

Core Questions Physics unit 4 - Atomic Structure Core Questions Physics unit 4 - Atomic Structure No. Question Answer 1 What did scientists think about atoms before the discovery of the They were tiny spheres that could not be broken up electron? 2 Which

More information

Sample Copyright. Academic Group ATOMIC STRUCTURE 1. Topics covered in this chapter:

Sample Copyright. Academic Group ATOMIC STRUCTURE 1. Topics covered in this chapter: ATOMIC STRUCTURE Topics covered in this chapter:. Structure of the Atom.2 Atomic Number, Mass Number.3 Isotopes.4 The Mass Spectrometer.5 Atomic Structure and Light Spectra.6 Electron Arrangements in Atoms.7

More information

Pros and Cons of Water Analysis Methods

Pros and Cons of Water Analysis Methods Water Lens, LLC 4265 San Felipe, Suite 1100 Houston, Texas 77027 Office: (844) 987-5367 www.waterlensusa.com Pros and Cons of Water Analysis Methods Prepared by: Adam Garland, CTO Water Lens, LLC ICP-MS/OES

More information

X-ray practical: Crystallography

X-ray practical: Crystallography X-ray practical: Crystallography Aim: To familiarise oneself with the operation of Tex-X-Ometer spectrometer and to use it to determine the lattice spacing in NaCl and LiF single crystals. Background:

More information

Classical and Planck picture. Planck s constant. Question. Quantum explanation for the Wein Effect.

Classical and Planck picture. Planck s constant. Question. Quantum explanation for the Wein Effect. 6.1 Quantum Physics. Particle Nature of Light Particle nature of Light Blackbody Radiation Photoelectric Effect Properties of photons Ionizing radiation Radiation damage x-rays Compton effect X-ray diffraction

More information

Praktikum zur. Materialanalytik

Praktikum zur. Materialanalytik Praktikum zur Materialanalytik Energy Dispersive X-ray Spectroscopy B513 Stand: 19.10.2016 Contents 1 Introduction... 2 2. Fundamental Physics and Notation... 3 2.1. Alignments of the microscope... 3 2.2.

More information

GAMMA RAY SPECTROSCOPY

GAMMA RAY SPECTROSCOPY GAMMA RAY SPECTROSCOPY Gamma Ray Spectroscopy 1 In this experiment you will use a sodium iodide (NaI) detector along with a multichannel analyzer (MCA) to measure gamma ray energies from energy level transitions

More information

Energetic particles and their detection in situ (particle detectors) Part II. George Gloeckler

Energetic particles and their detection in situ (particle detectors) Part II. George Gloeckler Energetic particles and their detection in situ (particle detectors) Part II George Gloeckler University of Michigan, Ann Arbor, MI University of Maryland, College Park, MD Simple particle detectors Gas-filled

More information

Advances in Field-Portable XRF

Advances in Field-Portable XRF Advances in Field-Portable XRF Volker Thomsen and Debbie Schatzlein Field-portable x-ray fluorescence (XRF) allows us to take the laboratory to the sample. The latest generation of such handheld x-ray

More information

Classification of spectroscopic methods

Classification of spectroscopic methods Introduction Spectroscopy is the study of the interaction between the electromagnetic radiation and the matter. Spectrophotometry is the measurement of these interactions i.e. the measurement of the intensity

More information

10.1 RADIOACTIVE DECAY

10.1 RADIOACTIVE DECAY 10.1 RADIOACTIVE DECAY When Henri Becquerel placed uranium salts on a photographic plate and then developed the plate, he found a foggy image. The image was caused by rays that had not been observed before.

More information

LAB 01 X-RAY EMISSION & ABSORPTION

LAB 01 X-RAY EMISSION & ABSORPTION LAB 0 X-RAY EMISSION & ABSORPTION REPORT BY: TEAM MEMBER NAME: Ashley Tsai LAB SECTION No. 05 GROUP 2 EXPERIMENT DATE: Feb., 204 SUBMISSION DATE: Feb. 8, 204 Page of 3 ABSTRACT The goal of this experiment

More information

Higher Physics. Particles and Waves

Higher Physics. Particles and Waves Perth Academy Physics Department Higher Physics Particles and Waves Particles and Waves Homework Standard Model 1 Electric Fields and Potential Difference 2 Radioactivity 3 Fusion & Fission 4 The Photoelectric

More information

Understanding X-rays: The electromagnetic spectrum

Understanding X-rays: The electromagnetic spectrum Understanding X-rays: The electromagnetic spectrum 1 ULa 13.61 kev 0.09 nm BeKa 0.11 kev 11.27 nm E = hn = h c l where, E : energy, h : Planck's constant, n : frequency c : speed of light in vacuum, l

More information

PHOTOELECTRON SPECTROSCOPY IN AIR (PESA)

PHOTOELECTRON SPECTROSCOPY IN AIR (PESA) PHOTOELECTRON SPECTROSCOPY IN AIR (PESA) LEADERS IN GAS DETECTION Since 1977 Model AC-3 Features: Atmospheric pressure operation (unique in the world) Estimate work function, ionization potential, density

More information

Practical 1P4 Energy Levels and Band Gaps

Practical 1P4 Energy Levels and Band Gaps Practical 1P4 Energy Levels and Band Gaps What you should learn from this practical Science This practical illustrates some of the points from the lecture course on Elementary Quantum Mechanics and Bonding

More information

Analytical Methods for Materials

Analytical Methods for Materials Analytical Methods for Materials Lesson 6 Production & Properties of X-rays Suggested Reading Chapter 1 in Waseda et al. Section 2.1 in Leng Other Reference B.D. Cullity and S.R. Stock, Elements of X-ray

More information

MODULE 4.3 Atmospheric analysis of particulates

MODULE 4.3 Atmospheric analysis of particulates MODULE 4.3 Atmospheric analysis of particulates Measurement And Characterisation Of The Particulate Content 1 Total particulate concentration 1 Composition of the particulate 1 Determination of particle

More information

Harris: Quantitative Chemical Analysis, Eight Edition

Harris: Quantitative Chemical Analysis, Eight Edition Harris: Quantitative Chemical Analysis, Eight Edition CHAPTER 21: MASS SPECTROMETRY CHAPTER 21: Opener 21.0 Mass Spectrometry Mass Spectrometry provides information about 1) The elemental composition of

More information

DAY LABORATORY EXERCISE: SPECTROSCOPY

DAY LABORATORY EXERCISE: SPECTROSCOPY AS101 - Day Laboratory: Spectroscopy Page 1 DAY LABORATORY EXERCISE: SPECTROSCOPY Goals: To see light dispersed into its constituent colors To study how temperature, light intensity, and light color are

More information

R O Y G B V. Spin States. Outer Shell Electrons. Molecular Rotations. Inner Shell Electrons. Molecular Vibrations. Nuclear Transitions

R O Y G B V. Spin States. Outer Shell Electrons. Molecular Rotations. Inner Shell Electrons. Molecular Vibrations. Nuclear Transitions Spin States Molecular Rotations Molecular Vibrations Outer Shell Electrons Inner Shell Electrons Nuclear Transitions NMR EPR Microwave Absorption Spectroscopy Infrared Absorption Spectroscopy UV-vis Absorption,

More information

2001 Spectrometers. Instrument Machinery. Movies from this presentation can be access at

2001 Spectrometers. Instrument Machinery. Movies from this presentation can be access at 2001 Spectrometers Instrument Machinery Movies from this presentation can be access at http://www.shsu.edu/~chm_tgc/sounds/sound.html Chp20: 1 Optical Instruments Instrument Components Components of various

More information

10/2/2008. hc λ. νλ =c. proportional to frequency. Energy is inversely proportional to wavelength And is directly proportional to wavenumber

10/2/2008. hc λ. νλ =c. proportional to frequency. Energy is inversely proportional to wavelength And is directly proportional to wavenumber CH217 Fundamentals of Analytical Chemistry Module Leader: Dr. Alison Willows Electromagnetic spectrum Properties of electromagnetic radiation Many properties of electromagnetic radiation can be described

More information

This experiment is included in the XRP 4.0 X-ray solid state, XRS 4.0 X-ray structural analysis, and XRC 4.0 X-ray characteristics upgrade sets.

This experiment is included in the XRP 4.0 X-ray solid state, XRS 4.0 X-ray structural analysis, and XRC 4.0 X-ray characteristics upgrade sets. The intensity of characteristic X-rays as a TEP Related topics Characteristic X-radiation, energy levels, Bragg s law, and intensity of characteristic X-rays Principle The X-ray spectrum of an X-ray tube

More information

Lecture 23 X-Ray & UV Techniques

Lecture 23 X-Ray & UV Techniques Lecture 23 X-Ray & UV Techniques Schroder: Chapter 11.3 1/50 Announcements Homework 6/6: Will be online on later today. Due Wednesday June 6th at 10:00am. I will return it at the final exam (14 th June).

More information

EDS User School. Principles of Electron Beam Microanalysis

EDS User School. Principles of Electron Beam Microanalysis EDS User School Principles of Electron Beam Microanalysis Outline 1.) Beam-specimen interactions 2.) EDS spectra: Origin of Bremsstrahlung and characteristic peaks 3.) Moseley s law 4.) Characteristic

More information

Basic physics Questions

Basic physics Questions Chapter1 Basic physics Questions S. Ilyas 1. Which of the following statements regarding protons are correct? a. They have a negative charge b. They are equal to the number of electrons in a non-ionized

More information

CASSY Lab. Manual ( )

CASSY Lab. Manual ( ) CASSY Lab Manual (524 202) Moseley's law (K-line x-ray fluorescence) CASSY Lab 271 can also be carried out with Pocket-CASSY Load example Safety notes The X-ray apparatus fulfils all regulations on the

More information

Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry

Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry Chapter 13 An Introduction to Ultraviolet/Visible Molecular Absorption Spectrometry 13A Measurement Of Transmittance and Absorbance Absorption measurements based upon ultraviolet and visible radiation

More information

Chemical Analysis in TEM: XEDS, EELS and EFTEM. HRTEM PhD course Lecture 5

Chemical Analysis in TEM: XEDS, EELS and EFTEM. HRTEM PhD course Lecture 5 Chemical Analysis in TEM: XEDS, EELS and EFTEM HRTEM PhD course Lecture 5 1 Part IV Subject Chapter Prio x-ray spectrometry 32 1 Spectra and mapping 33 2 Qualitative XEDS 34 1 Quantitative XEDS 35.1-35.4

More information

Introduction to light Light is a form of energy called electromagnetic radiation. A chart of the electromagnetic spectrum is shown below.

Introduction to light Light is a form of energy called electromagnetic radiation. A chart of the electromagnetic spectrum is shown below. Experiment: Spectroscopy Introduction to light Light is a form of energy called electromagnetic radiation. A chart of the electromagnetic spectrum is shown below. Radiowave Microwave Infrared Visible Ultraviolet

More information

Explain how line spectra are produced. In your answer you should describe:

Explain how line spectra are produced. In your answer you should describe: The diagram below shows the line spectrum of a gas. Explain how line spectra are produced. In your answer you should describe: how the collisions of charged particles with gas atoms can cause the atoms

More information

Particles and Waves Final Revision Exam Questions Part 1

Particles and Waves Final Revision Exam Questions Part 1 Particles and Waves Final Revision Exam Questions Part 1 Cover image: cutaway diagram of CERN, CERN Version 2013 P&W: Exam Questions Part 1 Version 2013 Contents Section 1: The Standard Model 1 Section

More information

Radiation Dose, Biology & Risk

Radiation Dose, Biology & Risk ENGG 167 MEDICAL IMAGING Lecture 2: Sept. 27 Radiation Dosimetry & Risk References: The Essential Physics of Medical Imaging, Bushberg et al, 2 nd ed. Radiation Detection and Measurement, Knoll, 2 nd Ed.

More information