Alessandro Variola, Fabian Zomer (LAL, Orsay)

Transcription

1 IN2P3 Les deux infinis Alessandro Variola, Fabian Zomer (LAL, Orsay) Alexandre Loulergue, Nicolas Hubert (SOLEIL) The ThomX Project The ThomX Project Work supported by the EQUIPEX program, the Ile de Work supported by the EQUIPEX program Ministère de la recherche, Ile-de-France region, CNRS-IN2P3 and Université Paris Sud XI Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 1

2 The ThomX Project Compton effect ThomX is a light source based on Compton Back Scattering (CBS) Why CBS? - CBS is by far the most efficient photon energy amplifier : ω diff =4γ 2 ω laser, ThomX => γ~100 => it is possible to have at one s disposal hard X rays with a relatively low energy electron machine. Example : 50 MeV electrons and 1.23 ev laser give up to 50 kev back scattered X-rays - But for a light source: σ (Compton cross section) ~ cm 2, it is low!!!!! - Thomx target is a high AVERAGE flux so we need many electrons and photons colliding in a small volume at high frep => CHOICE: - Storage ring + high average power laser amplified in a Fabry Perot resonator (French collaboration among different kinds of expertise ) Target : Store one electron bunch of 1 nc over 20 ms in the ring Store one laser pulse of 25 mj in the FP cavity => Ph/s ==> Thom-X is a demonstrator Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 2

3 How it works ThomX scheme and design X-rays RF gun 3 GHz Cycle Frep = 20 msec RF pulse length 3 µs Energy MeV Easy integration 2 Interaction Points in the arcs Frees the straight sections Linac 3 GHz MeV Linac dump & diag Laser and FP cavity Feedback system & RF 500 MHz E-diag Interaction point 7 m. Matching section Inj & Ext section Ring dump 10 m. Acknowledgments to M.Jore, M Lacroix Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 3

4 Scientific Case Transfer of the SR techniques to these new machines. Many fields can be interested At present two contributors: Medical field (ESRF, INSERM Grenoble) Cultural Heritage (C2RMF CNRS Louvre Museum) Painting analysis Cultural heritage and medical science Physiopathology and Contrast agents, Dynamic Contrast Enhancement SRCT Convection Enhanced Delivery =>Stereotactic Synchrotron RT Paleontology Non-destructive analysis Imaging, Mammography Microtomography Biston et al, Cancer Res 2004, 64, K-edge imaging (Pbwhite, Hg vermilion ) of a Van-Gogh s painting J. Dik et al., Analytical Chemistry, 2008, 80, 6436 J Cereb Blood Flow and Metab, (2): Journal of Radiology 53, (2005) Thanks to G.Le Duc, P.Walter Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 4

5 Expected beams characteristics Injector, ring, laser, Fabry-Perot resonator and the source Injector Ring Charge 1 nc in 1 bunch Energy 50 MeV (70 MeV possible) Laser wavelength and pulse power 266 nm, 100 µj Gun Q and Rs 14400, 49 MW/m Gun accelerating gradient MW Normalized r.m.s emittance 8 π mm mrad Energy spread 0.36% Bunch length 3.7 ps Laser and FP cavity Laser wavelength 1030 nm Laser and FP cavity Frep 36 MHz Laser Power W FP cavity finesse / gain / FP waist 70 µm Source Photon energy cut off 46 kev (@50 MeV), 90 kev (@ 70 MeV) Total Flux ph/sec Bandwidth 1 % - 10% Circumference 16.8 m Crossing-Angle (full) 2 degrees B IP 0.2 m Emittance x,y (without IBS and Compton) m Bunch length (@ 20 ms) 30 ps Beam current ma RF frequency 500 MHz Transverse / longitudinal damping time 1 s /0.5 s RF Voltage 300 kv Revolution frequency 17.8 MHz Harmonic Number 28 σ IP (injection) 78 mm Tune x / y 3.4 / 1.74 Momentum compaction factor α c Final Energy spread 0.6 % Divergence Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 1/γ ~ 10 mrad without 50 MeV 5

6 Ring Linear optics and mechanics Dynamic aperture < physic aperture (28*40mm) Supports X Line Pumping and integrated SR port SR port Pumping ports Bellows Acknowledgments to A.Loulergue, T.Vandenberghe, C.Prevost, B Mericer, A. Gonnin, R.Marie Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 6

7 Ring injection dynamics Longitudinal mismatch 1 nc 50 MeV Typical longitudinal shape from the linac Strongly mismatch in the ring Undergoes turbulent dynamics Strong collective effects Strong Needs: Position feedback in the 3 planes Side effects : Horizontal emittance increase Main risk : To brake the bunch / losses Finally reach a ring matched form Still subject to some head tail effects Acknowledgments A. Loulergue Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 7

8 Ring injection dynamics Transverse side effect from longitudinal mismatch Transverse emittance in the first turns versus chromaticities 6D tracking : symplectic mapping + long. Collective effects at 50 MeV, 1 nc turns =0.5 ms Over 20 ms storage Long. Turbulent time Horizontal Stable with Chro-X > 0 Vertical : no skew error Acknowledgments A. Loulergue Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 8

9 Ring dynamics Compton recoil and Intra-Beam Scattering effects 50 MeV, 1 nc Horizontal emittance x 6 over 50 ms ==> IBS dominated Relative E-spread x 2 over 50 ms ==> CBS dominated Electron beam density reduction -> X-Rays flux reduced by ~2 over 50 ms Acknowledgments A. Loulergue Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 9

10 Injection One septum, two kickers 2 kickers (15 mrad): - injection - Extraction 1 septum (150 mrad) R&D for kicker pulsers (pulse <= 1 turn=56ns) Clean extraction - Dedicated extraction kicker - Beam dump Extraction in foreseen to be done few turns before new injection Acknowledgments to P.Lebasque, T Vandenberghe Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 10

11 Diagnostics Diagnostics for ThomX: Charge (BCM x3) Position (5 striplines, 12+1 button BPMs) Ion cleaning (polarization on 1 button bpm) Tune (oscillation at injection + BPM) Bergoz in-flange ICT Beam position monitors Transverse size (screens: YAG + OTR) Emittance (Q-scan + screen, Pepper pot + screen) Energy (Dipole + screen) Diagnostic station x4 FBT Stripline Length (Cherenkov@LINAC /synchrotron radiation@ring + streak camera) Feedbacks Acknowledgments to M.Lacroix, Y.Peinnaud Bunch length measurement Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 11

12 Fabry-Perot cavity Towards ThomX Dipoles Integration Dedicated BPM Bakable Easy to access, mounting 2 degrees collisions Laser insertion Laser and FP cavity Laser wavelength Laser and FP cavity Frep Laser Power 1030 nm 36 MHz W FP cavity finesse / gain / FP waist 70 µm Acknowledgments to M.Lacroix, Y.Peinnaud Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 12

13 Synchronisation Acknowledgments to N. Delerue Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 13

14 X ray line X ray characterization. beam divergence 20 mrad Ultra-vacuum air vacuum Hodeau box Transfocator Slit Beam Profile Shutter Fluorescent screen Diaphragm Diode detector Acknowledgments to M.Jacquet, J.L Hodeau, J.L Hazemann, P.Jeantet Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 14

15 Integration and Site Paris-Sud University Campus OLD Orsay IGLOO Acknowledgments to A.Pichot, M.Tran Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 15

16 Planning 2010 CDR 2011 Founded by EQUIPEX program 2012 TDR 2013 Equipments order 2014 Installation - commissioning 2015 commissioning - photon Acknowledgments to A.Pichot, M.Tran Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 16

17 Conclusions Compton effect : new generation of gamma and X source Very nice accelerator and laser physics Different kinds of expertise in French Labs => Compton X Rays source Collaboration established, CDR published Financing!!!! Equipex (French minister), Ile-de-France Region, CNRS- IN2P3, Université Paris Sud XI Industrial collaboration: ThomX can be industrialized as an allintegrated product Construction starts in 2013 Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 17

18 Nicolas HUBERT Libera Workshop, October 11-12,2012, Sveta Gora 18