Synchrotron Radiation in IRAN

Transcription

1 Synchrotron Radiation in IRAN Helmut Wiedemann, Stanford University Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 1

2 Synchrotron Radiation is the tool of choice to study atomic and molecular structures Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 2

3 Synchrotron Radiation is used for Basic and Applied Research in fields like: Material Science Physics Biology Chemistry Medicine Geology Environmental Science Archeology Integrated Circuits Nuclear Physics Forensics Waste Remediation Drug Development wherever atomic and molecular structures are of interest Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 3

4 how do we generate synchrotron radiation? we build a circular electron accelerator, a storage ring Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 4

5 main synchrotron/storage ring components photon beam line rf-cavity injection system focusing bending vacuum chamber e - Insertion device beam line Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 5

6 Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 6

7 Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 7

8 why a synchrotron radiation facility in Iran? Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 8

9 Education University based research (about 50-70%) extension of University research (providing expensive instrumentation) masters and PhD programs : about 100 PhDs/year from NSLS and SSRL Publications (1997): BLs PUBs PRL Science Nature SSRL: NSLS: Nobel Prize to R. Kornberg (Stanford) Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran

10 Technical Development magnet technology (precision machining) ultra high vacuum technology rf-technology optics, spectrometers, imaging precision alignment of large systems control systems computer control/data acquisition electronics measurement techniques operation / maintenance organization/management/administration Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran

11 Industrial/Governmental Involvement drug development future integrated circuits materials like plastic, rubber, fibers, silk corrosion micromachining energy storage (e.g. hydrogen cells for automobiles) governmental application (security) Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran

12 School of Accelerators and Particles at the IPM is studying the design of synchrotron radiation sources has assembled in 2010 an enthusiastic project group of physicist and engineers have compiled a conceptual design report (CDR) identifying critical issues understand functionality of main facility components lattice design and linear/nonlinear beam dynamics ready to build a prototype bending magnet get ready for magnetic measurement prepare to build solid state amplifiers for RF collaborate with foreign laboratories for hands-on training set up a management structure Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 12

13 ILSF group is forcefully and effectively preparing on broad base these preparations during 2010 set the base to make the next step think about options think about optimization satisfy the particular needs of Iranian users meet particular design goal minimize cost, schedule and effort Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 13

14 To this effort I would like to add some suggestions: what should be the parameters of the ILSF? when will ISLF be available? ? will the design parameters still be up-to-date then? will technology advance we have to think ahead Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 14

15 consider design alternatives there are advantages/disadvantages to all designs what are the most important design feature? how can you proceed in existing economic environment? how can technology help us to minimize risk reduce construction and operating costs Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 15

16 main storage ring parameters? energy current 3 GeV 500 ma photon spectrum source size beam emittance photon beam brightness hard x-rays, > kev as mall as possible, <~ 1 nm undulator radiation source magnet free insertion sections for IDs many 6 12 m long all have impact on construction cost operating cost $$$$$$$ Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 16

17 electron beam energy and current energy 3 GeV is most common technologies exists to create desired spectrum current as much as possible and affordable technology limit (absorber) at about 500 ma Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 17

18 Biology most likely will be the most prominent future user community they need photon energies kev, sometimes lower, broad band or variable if monochromatic this also fits most other users Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 18

19 Bending magnet or wiggler magnet radiation log I log w is broad band up to 3-5 x critical photon energy c 3 2 c 3 c kev 2.22 E 3 GeV m w c E GeV B T Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 19

20 Beam Emittance source size: as small as possible (diffraction limit) small sample, aberrations energy resolution small beam emittance photon beam brightness B photons 4 x x y y E E ph t photons mm 2 mrad 2 0.1%BW s B 1 2 small beam emittance Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 20

21 how small an emittance? diffraction limit for ph 4 1Å ph m not possible with present technology E 2 3 many bending magnets larger circumference recent SRs have emittances of ~ 3 5 nm, future rings ~ 1 nm with 10 in Brightness! ILSF 1nm Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 21

22 Brightness is the photon density in phase space B photons 4 x x y y E E ph t photons mm 2 mrad 2 0.1%BW s need low emittance undulators with many periods N p, because long straight sections for long undulators long straight sections for 2 undulators t E E ph 1 N p bunch length limited to ps for technical reasons Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 22

23 Undulator Radiation Pattern need long undulators with many periods to get small band width Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 24

24 Undulator emits quasi-monochromatic radiation l p period length of undulator fundamental wavelength of undulator radiation p K2 p K2 Lorentz Contraction Doppler Effect Undulator strength parameter K 0.934B T p cm where q is the maximum deflection angle from the axis Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 24

25 l l p K2 2 2 q obs Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 25

26 Standard Spring-8 in vacuum undulator l p = 32 mm, N p = 140, gap > 8 mm, K max = 2.3, L = 4.5 m Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 26

27 suggestions for alternative ILSF storage ring option goals while not compromising performance: lower beam emittance (from 3.2 to <=1 nm) more and longer straight sections green machine - minimize power consumption easier design of components lower component costs lower operating costs unwanted impact: increased ring circumference! Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 27

28 0 2,000 1,000 4,000 3,000 6,000 5,000 8,000 7,000 10,000 9,000 12,000 11,000 14,000 13,000 16,000 15,000-1,400-1,200-1,000 mm x, magnetic midplane field, B_y(x,0.0) use low field bending magnets (0.5T instead 1.4T) produce hard x-ray bending magnet radiation only where needed low field, 0.5 T, 6 0 low field, 0.5 T, T 1 0 low field, 0.5 T, magnetic midplane field, B_y(x,0.0) -1,400-1,200-1, x, mm Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 28

29 low field bending magnets (0.5T instead 1.4T) benefits: lower beam emittance 1.2 nm (by factor 2.8) higher photon beam brightness (by factor 8) less magnet power (-64%) less radiation from bending magnets use high field inserts for hard x-rays less rf-power (-400 kw) less cooling of vacuum chamber more/longer straight sections (10x10.5m, 10x5.5m) vs (4x7.8m, 16x4m, 12x2.8m) negative circumference increases by 150m Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 29

30 solid state amplifiers for RF-system: conventional microwave power sources are klystrons expensive and hard to repair solid state amplifiers ~800 to 1000 W combine many to get 100 kw units can be developed locally with local components if one fails, just replace malfunctioning amplifier need 400 kw less in low field magnet option Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 30

31 before final decision need to consider a variety of lattice options in consultation with users in consultation with technical groups/interests in consultation with management to Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 31

32 eventually arrive at a truly Iranian design serving Iranian Science Community Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 32

33 I wish you and the ISLF continuing Good Progress and Good Luck Thank you Synchrotron Radiation in IRAN, Helmut Wiedemann, IPM, May 18, 2011, Tehran 33