MeV photons from inverse Compton scattering and applications for science

Transcription

1 MeV photons from inverse Compton scattering and applications for science M. Saskatoon workshop 22-23, April Coherent Compton Scattering New aspect for inverse Compton Scattering (BCS γ-ray generation) 2. Nondestructive Radionuclide Assay

2 Collaborators: T. Hayakawa, N. Kikuzawa, R. Hajima, T. Shizuma, N. Nishimori, M. Seya, K. Kawase, and others (JAEA) Special Thanks to D. Habs, T. Tajima, J. Schreiber, C.P.J. Barty, P.G. Thirolf

3 σ T = 8π e e 3 4πε0mc 2 2 = cm 2 σ T Ζ 2 σ T Ν 2 σ T

4 φ φ φ ω φ φ ω γ d x n z i u n n d d N d n n n N n )) ( ) ( ( ))exp( ( ( Ω = + F.V. Hartemann, T. Tajima et al., Lawrence Livermore Lab. reprint Electrons are trapped by laser force Very short electron packet Very short laser

5 F = ev B Nature 431 (2004) 535

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7 NIM425 (1999) 65, V. Nelyubin, M. Fujiwara, T. Nakano, B. Wojtsekhowski

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9 Transmutation of actinide nuclei by photo-fission For example, the transmutation of Np by neutron induced nuclear fission, fission fragments with wide masses near A=120 remain. One serious RI is 129 I with a long half-life. Can we control the fission mode by selecting a special mode of fission? One possible route is to use Nuclear Resonance Fluorescence (NFR) Potential barrier and photo-fission Horizontal axis: nuclear deformation, Vertical axis: depth of potential. We irradiate 4 MeV photons to a stable nucleus with a deformation 0. Then, the levels in the first potential with 0 deformation are excited. The excited levels couple to the vibration level in the second potential, inducing an abnormal photo-fission mode. It is well known that there are the second-, and third-potential in addition to the first potential in actinide nuclei, when we consider the fission processes. One can use the coupling mechanism between the levels in the first- and second potentials. Theoretically, it is predicted that the mass distribution of the fission fragment is different from those of the usual neutron induced fission fragments. Feasibility test by photon-beams from FEL Back-Compton photons are an interesting research subject. Parity mixing may also play a role! Idea comes from by Dr. Nishio of JAERI.

10 Nucleosynthesis by high energy photons Heavy elements have been produced by stars in the Galaxy. Massive stars have contaminations of heavy elements synthesized at early generation stars. Massive Star New isotopes are produced by photons in supernova explosions. Supernova Explosion Temperature: 3x10 9 K! C Mg/Si Fe H He O/ Ne H H Seed Nuclues Nucleosynthsis New nucleus Photon Neutron Photon Neutron Goko et al., (Konan group) PRL 96, (2006)

11 Proposal of Novel Nondestructive Radionuclide Assay Energy [kev] Tunable Nuclear Resonance Fluorescence Shielded Materials Flux of gamma-rays Fe Absorption Emission Absorption Emission / / Pb 239 Pu 235 U 238 U Gamma-ray beam Hidden nuclides as U-235 Detector Hajiam et al. has proposed a novel method that measure any radionuclide inside a heavy shield as a few cm thickness steel. Energy tunable mono-chromatic gamma-ray beam Identification with Nuclear Resonance Fluorescence R.Hajima, T.Hayakawa, N.Kikuzawa, E.Minehara, J. Nucl. Sci. Tech. 45, 441 (2008).

12 Management of nuclear waste Clearance 27 万円 / 本 Ground Drams of nuclear wastes Depending on radioactivities Nondestructive radionuclide assay is crucial for the classification. Correct classification is important for the safety and cost 300 万円 / 本 800 万円 / 本 Deep 三代理事の資料より

13 Cycle of used nuclear fuel A new generation of nuclear fuel cycle Cycle without Water Project for Nuclear Separation and Transmutation technology (under discussion at government level) In this method, standard assay system Can not be used.

14 Development of Detection methods A proof-of-principle experiment Selection of detector (Ge semi-conductor, NaI, LaBr 3 ) Design of geometry of detectors High background from RI We have developed a simulation code based on a library GEANT 4 for design of the detection system. An example of simulation Peak of U-238 Drams of nuclear waste including U-238 Detectors Expected energy spectrum

15 A proof-of-principle Experiment at AIST TERAS Electron Storage Ring Electrons Laser LCS γ rays Flux Monitor Colision laser Target γ Ray Detector LCS gamma-ray source at TERAS in AIST Electron storage ring TERAS Nd:YVO4 Q-switched laser 1064 nm 570 MeV electrons

16 Detection of Pb hidden by 15-mm thickness iron plates Flux Monitor y x Pb-208 HPGe detector HPGe detector 20mm z LCS gamma-rays Target Experimental Setup Two High Pure Ge semi-conductor detectors NaI(Tl) Flux Monitor Fe There occurs Nuclear Resonance Fluorescence, if Pb-208 exists.

17 Result Counts Counts 10 We used Pb-208 instead of U-238, since we cannot use it at AIST Energy (kev) y = -8m m y = -12m m Pb-208 No Pb-208 Peak of Pb Pb (5.512M ev ) Energy (kev) Position (mm) Position of Pb 0.E+00 1.E-07 2.E-07 3.E-07 4.E-07 5.E-07 Counts/ph Yields of Pb-208 We detected Pb-208 hidden by 15mm iron N.Kikuzawa, Appl. Phys. Exp. 2, (2009)

18 Counter Terrorism Monitor system in a gate in nuclear plant, military base, and airport Passport System Inc. ( Lawrence Livermore National Laboratory Detection of Uranium bomb In a cargo. Pruet, Apply. Phys. Lett. 2005

19 Proposal of nondestructive assay Energy Flux of gamma-rays of chemical compound Pb Absorption C AIST Electron Storage Ring TERAS Colision Emission Absorption Laser 14 N Emission We extend the nondestructive assay method to chemical compound. In this method, several key elements are measured at the same time with energy tuned LCS gamma-ray. Electrons Laser Collimator Flux Monitor Target We carry out a proof-ofprinciple experiment A chemical compound, melamine (C 3 H 6 N 6 ), Is used as a test material

20 A proof-of-principle experiment Melamine target is shielded by 15-mm iron and 5-mm lead. カウント LCS energy spectrum N-14 and C-12 are Covered kev : 14 N 4439 kev : 12 C カウント NRF gamma-ray spectrum kev : 12 C kev : 14 N kev : 208 Pb エネルギー [MeV] エネルギー [kev] Exp= Melamine=0.5 We carried out a proof-ofprinciple experiment T.Hayakawa, Rev. Sci. Inst. 80, (2009)

21 Development of a new generation of ERL systems in JAPAN Compact LCS Gamma-ray source based on ERL with energy of a few 10 kev for material science ( ) Prototype of high-power ERL is under Construction by KEK- JAEA-ISSP (complete in 2012) normalized emittance = 0.054mm-mrad Laser Super Cavity for generation of Gamma-rays

22 High flux LCS source in future We have designed extremely high-flux gamma-ray source based on ERL. Laser Super Cavity Detection system Detectors Compton scattering γ-ray 3rd E=350 MeV Nuclear Fuel 2nd E=235 MeV 1st E=120 MeV Injector Linac Dump High Power ERL This system is constructed by new generation of accelerator and laser technology photons/(kev s) Flux is 6-8 order magnitudes Applications for Nuclear Engineering higher than available sources.

23 Proposal for detection system for nuclear material safeguards Concrete Wall Dump Spent Fuel Pool Water Detector system Concrete Wall Water Measurement Room Concrete Wall Measurement Room Linac/Laser Area Spent Fuel Assembly 3 m LCS Gamma-rays Wall Nuclear Fuel Assembly Ge detectors Water pool Terrorist and spy cannot access spent nuclear fuel to steal fissional materials. Hayakawa, et al. submitted to NIMA.

24 Simulation for proposed system We have extended GEANT4 to calculate NRF Position X [mm] Nuclear Fuel Rods Position Y [mm] Our designed system can observe Pu-239 in all rods. Hayakawa, et al. submitted to NIMA.

25 Development for industrial application with Microtron In general industrial applications, although extremely high flux is not requeired, the size should be small. 4 m

26 Generation of LCS gamma rays with Microtorn in JAEA We have generated LCS gamma-rays using 150 MeV microtron in JAEA. Detector LCS gamma-rays Incident angle: 16 4 m Bending magnet Microtron Electron beam dump Nd:YAG laser Photocathode RF-gun Synchronized operation Nd:YAG laser (Continuum Powerlite 9010) Pulse duration Output Repetition 23 ns (FWHM) 1 J (1064 nm) 10 Hz Microtron Energy Pulse duration Charge Repetition 150 MeV 10 ps (rms) 60 pc/pulse 10 Hz

27 Result Total energy of LCS gamma-rays in an electron pulse by LYSO (Mean energy number of photons) Demonstration Of imaging Laser on Laser off Target Number of gamma-rays is about 200 photons/pulse Result of IP for 2 hours K. Kawase et al., Rev. Sci. Inst. 79, (2008) K. Kawase et al., NIMA, in press (2010).

28 CERN Courier January/February 2010 X-ray generation from inverse Compton scattering between laser and ERL electrons

29 Summary 1.Possibility of Coherent LCS 2.New projects with ERL