Activities at the Laboratory of the Nuclear Engineering Department of the Polytechnic University of Valencia

7 th Workshop on European Collaboration for Higher Education and Research in Nuclear Engineering & Radiological Protection Bruxelles, Belgique 30 May - 1 June 2011 Activities at the Laboratory of the Nuclear Engineering Department of the Polytechnic University of Valencia B. Juste 1, J. Ródenas 1, R. Miró 1, S. Gallardo 1, J. Ortiz 1, R. Sanchis 1, A. Escribá 1, J. Sancho 1, S. Martorell 1 1 Chemical and Nuclear Engineering Department. Universidad Politécnica de Valencia, Spain

Nuclear Physics Laboratory The Nuclear Physics Laboratory from the Nuclear Engineering Department at the UPV has its main activity in the field of radiation dosimetry and activity measurement and it is oriented to the undergraduate (mostly 4th or 5th year and Master) students from UPV. Students carry out physics experiments, analyzing their results, estimating experimental errors and individually writing and submitting the laboratory reports. The choice of experiments in the Laboratory is consistent with the program of the different subjects and lectures given at faculties of Industrial and Chemistry Engineering of Valencia. The experiments in the Laboratory are organized in two main groups: ionizing radiation optics Normally, students work in teams of 2 or 3 persons and they should carry out the experiment and progress with data analysis. Prior to practical exercises, all students have to know safety rules related to handling radioactive sources.

Nuclear Physics Laboratory experiments (A) Ionizing radiation Oscilloscopes and pulse-detection electronics. Geiger-Müller counter. Radiation and contamination monitors. Dosimeters. Scintillator detector. Semiconductor detector X-ray fluorescence analysis (XRFA)

Oscilloscopes and pulse-detection electronics GOAL: Learning the use of an oscilloscope and a pulse generator for signal tracing and measurements, and the use of pulse electronics components, such as preamplifieramplifier combination. Other counting circuit components are studied more briefly: discriminator, scaler, countrate meter. EXPERIMENT. Using the Pulser as the Linear Input to a Typical Counting System EQUIPMENT: Ortec bin modules and osciloscoppe.

Geiger-Müller detector GOAL: Investigation of Characteristics of the Geiger-Müller counter and statistical aspects of radioactive decay. EXPERIMENT: A Geiger counter is used to observe the properties of gas counters in the proportional and Geiger-Muller (G-M) regions. The G-M plateau is determined and dead-time and attenuation coefficient of lead and aluminium measured. EQUIPMENT: Ludlum Model 2200. Radiation Scaler/Ratemeter SCA Geiger muller inside lead shielding structure

Dosimeters Radiation and Contamination monitors This experiment aims to familiarize students with the most common measurement devices in radiation protection: Radiation monitors Contamination monitors Personal dosimeters

NaI detector GOAL: Investigation of energy spectra of γ-radiation using a NaI scintillator detector. EXPERIMENT: The acquisition of γ- spectra for several radiation sources and the determination of photo-peak positions and identification of Compton edges and back scattering peaks. The objective of the experiment is to acquire energy spectra using multichannel analyzers and analyze them with some computer programs (GammaVision and Genie) to obtain the energy and efficiency calibration. EQUIPMENT: Canberra NaI Scintillation Detector, 3- x 3-in. crystal, 3-in. tube

Germanium detector Because germanium has a relatively low band gap, these detectors must be cooled in order to reduce the thermal generation of charge carriers to an aceptable level. The CANBERRA Ultra-Low Ge detector extends the performance range of Ge detectors down to a few hundred electron volts, providing resolution, peak shape, and peak-to-background ratios once thought to be unattainable with semiconductor detectors. The goal of the experiment is to study the efficiency and resolution advantages of Ultra-Low Ge.

XRFA X-ray fluorescence analysis (XRFA) is used for quick and non-destructive elemental analyses of different samples. With a small 30 kv X-ray tube and a solid state detector (Si-pin diode from Amptek) students can analyze the characteristic peaks of several samples.

Nuclear Physics Laboratory experiments (B) Optics Spectrometer-Goniometer. Determining Planck s constant.

Spectrometer-Goniometer When used with a prism, students can observe visible light as it is dispersed according to its wavelength. When used with a diffraction grating and a gas discharge tube, students can observe the emission spectrum of various gases. Wavelengths of each electron transition in the spectrum can be calculated. EQUIPMENT: Spectrometer-Goniometer. 4 gas discharge lamps (Hq, Na, Cd, He)

Planck s constant Determining Planck s constant using the photoelectric effect, and assuring that only the light of a single spectral line of the high-pressure mercury vapor lamp falls on the cathode of the photocell at any one time after crossing a narrow-band interference filters to select different wavelengths. The capacitor is used to generate the opposing voltage U between the cathode and the anode of the photocell. The voltage at the capacitor is measured and plot. Planck constant can be determined by multiplying the slope of the graph by the charge of an electron.

Thank you for your attention

Thank you