An Overview of the Activities of ICS Sources in China

Transcription

1 An Overview of the Activities of ICS Sources in China Chuanxiang Tang *, Yingchao Du, Wenhui Huang * tang.xuh@tsinghua.edu.cn Department of Engineering physics, Tsinghua University, Beijing , China Nuclear Photonics 2018, June 24-29, 2018, Brasov, Romania

2 Content An Brief Introduction to ICS gamma-ray sources An overview of the activities in China Recent research on ICS source at Tsinghua University Performance and the experiments on TTX-I The projects of ICS sources by THU Summary

3 Electron Accelerator: electromagnetic wave frequency convertor RF Microwave THz Infrared Visible light UV X ray Gamma Ray Microwave tubes Interacted with structures Supplying RF Power Free Electron Laser & Synchrotron Radiation Magnetic Fields: Undulator or Dipole Inverse Compton Scattering Interacted with high power laser DC High Voltage

4 Advantages of TS/ICS Sources Small source size(~10 s um) Tunable energy from kev to MeV Quasi-monochromatic Radiation in a small divergence High peak brightness and spectral density Ultra-short X-ray Pulse Good synchronization for pumpprobe Tunable polarization Compact and affordable

5 ICS/TS Sources in China ICS-BEPC an Probe Construction Operation

6 SLEGS Project at Courtesy of Jianhui Chen

7 Flux of SLEGS Courtesy of Jianhui Chen

8 Technical Implementations of SLEGS Courtesy of Jianhui Chen

9 Gamma-ray at a conceptual design Courtesy of Jianhui Chen

10 IHEP: MeV Courtesy of Yongsheng Huang

11 Courtesy of Yongsheng Huang

12 γγ IHEP Courtesy of Yongsheng Huang

13 Courtesy of Yongsheng Huang

14 TS/ICS source Studies at Tsinghua University : TTX-I upgrade and TTX-II* XGLS-3MeV* Probe X-ray source for PTS * Compact γ-ray source TTX-I

15 Tsinghua Thomson scattering X-ray source (TTX): TTX-I is operating, TTX-II is under technical design. TTX-I: High Peak Brightness TTX-II: High Average Brightness Energy: 20-50keV Repetition Rate: ~10Hz Average X-ray Flux: ~ ph/s X-ray Pulse Length: fs-ps X-ray beam size at IP: ~10um Energy: keV Repetition Rate: ~10MHz Average X-ray Flux: ~10 12 ph/s X-ray Pulse Length: ~20ps X-ray beam size at IP: ~10-100um

16 The 50MeV Electron linac beam line of TTX The maximum gradient of the gun is ~110MV/m and the bunch charge from a few pc to ~1nC. An S-band TW cavity was installed for ballistic bunching before the acceleration. The acceleration phase is set at ~-90 to introduce an energy chirp Simulations show the emittance can be preserved when compression factor C<3 A 4-dipole chicane has been installed after the linac The bend angle can be varied up to ~15. The combination of ballistic bunching and magnetic compression enable us to generate ultrashort (rms<20fs) and high-intensity (~10kA) electron beam.

17 UV and IR Laser system UV driver laser for photocathode rf gun 30TW 800nm scattering laser

18 Upgrade of TTX-I photons/pulse 1E E E E NIM A 608 (2009), NIM A637(2011), RSI 84, (2013), NIM B402(2017)

19 X-ray spectra measurement with Highly Oriented Pyrolytic Graphite (HOPG) Bandwidth: 52.35keV ~2.3% RSI 88,045110(2017)

20 Advanced X-ray Imaging with TTX-I Small spot size, small divergence: Phase Contrast Imaging (including PC CT) Narrow Spectra: Mono-Energetic X-ray CT Tunable Energy: Multi-Energy X-ray Imaging (Material Identification, K-edge Imaging ) Short Pulse Length: Fast Process Imaging

21 In-line phase contrast imaging Shrimp Proc. SPIE 10391(2017)

22 Mono-energetic X-ray CT imaging at TTX n μ = ω ρ i mmm i=1 μ ρ i E. C. McCullough, Med. Phys., 1975 μ tttttt = 0.538cc 1 μ RRR,1 = 0.459cc 1 μ RRR,2 = 0.486cc 1

23 Multi-Energy Mono-energetic X-ray CT Imaging The effective atomic number Z eff and the electron density ρ e can be retrieved X-ray energy: 29keV and 68keV

24 The iodine solution K-edge imaging Original image R = I/I 0 image

25 The X-ray polarization control and measurement MC simulation of the polarization Theoretical : flux modulation X-ray from TTX MC simulation of the photon flux modulation MC simulation Experimental results Hongze Zhang, et al, Experimental Polarization Control of Thomson Scattering X/γ-ray Source arxiv: v2

26 Two color x-ray pulses from the twin-bunch

27 Two color x-ray pulses from the twin-bunch

28 Dual-energy X-ray generation

29 The projects of ICS sources by THU TTX-II with LESR and Optical Cavity (under technical design) Energy: keV Repetition Rate: ~50MHz Average X-ray Flux: ~10 12 ph/s X-ray Pulse Length: ~20ps X-ray beam size at IP: ~10-100um XU H., et al, PRSTAB, V17, (2014) XU H., et at, PRAB, V19, No.6, (2016) XU H., RSI V85 No (2014)

30 XGLS: a 3MeV ICS gamma-ray source Mono-Chromatic Mode drive laser:~mj, 266nm electron linac: ~400MeV X-ray and electron experimental hall scattering laser: ~5J, ~ps, 800nm Ultra-short pulse Mode

31 Status of the XGLS S-band photon-injector has been installed and is commissioning now. Charge: >500pC, Energy: ~110MeV, emittance: ~0.6mm mrad

32 A keV Thomson scattering x-ray source as a probe for PTS (a z-pinch facility) X-ray source for high energy density physics diagnostic: X-ray energy : keV Flux: 1-5x10 8 photons/pulse Spot size: <20um Pulse length: ~10ps

33 A Compact ICS Gamma Ray Source

34 The Compact ICS gamma-ray source can be installed in a standard container.

35 Storage Ring Based ICS Gamma Ray Source Gamma ray 1 ~10 12 ph/s ~10MeV ~MHz Gamma ray MeV Storage Ring Gamma ray N ~10 9 ph/pulse ~1ps ~10MeV Gamma ray with high peak brightness ~100TW Laser Gamma ray 3 800MeV Linac with Photocathode RF Gun

36 emittance 3.37 dispersion less than 0.4m,zero dispersion at drift section energy of the γ-ray: 4~20MeV Circumstance 59.14m,4 cells Drift section 4.045m Electron energy at 500MeV,to 800MeV Lattice: 5BA Zhilong Pan, Changchun Sun, John Byrd,Y.K.Wu, Hao Hao,Wenhui Huang, and Chuanxiang Tang, Design and dynamic simulation for a compact storage ring to generate gamma-ray light source based on Compton scattering, to be

37 Summary TTX-I has been supplying x-ray beams for experiments. X-ray imaging and other applications have been carried out. Several projects of ICS source: SLEGS, TTX-II, XGLS and Probe X-ray Source for PTS are under construction in China A Compact gamma-ray source based on high gradient linacs has been designed. A storage ring based multi-user ICS gamma-ray source with photon energy of MeV, can be a good facility for nuclear physics and other researches.

38 Thanks!