D_R&D_6 Liquid xenon detector technology Workshop FJPPL’07, 9-12 May 2007, KEK, Japan 3  Medical Imaging with liquid xenon and 44 Sc Eric Morteau, Patrick Le Ray, Cyril Grignon Noel Servagent, Jean-Pierre Cussonneau Dominique Thers (Nantes) Tom Haruyama (KEK) Wednesday, 09 May 2007

1. 3  Medical Imaging : concept and motivation Sc production at ARRONAX 3. Simulation and expected results with liquid xenon telescope 4. Liquid xenon technology 5. Expected schedule and Milestones

3  Medical Imaging – never imagined before ? Not a “standard” imaging !

Positron Emission Tomography with  + emitters  + disintegration LL Main incertitude on the emitter position : LOR length 1 mm5 mmLOR 2D ~ 6 cm~ 30 cm LL Rat bodyHuman body TOF-PET (260 ps)  L ~ 9 cm T. Doke et al. NIMA 569 (2006) Sub-centimetre precision along the LOR achievable ?

Single  detection with a Compton telescope Measured Event quantities: E 1 = Energy lost by the scattered electron at the first hit x 1,y 1,z 1 = First Interaction Location x 2,y 2,z 2 = Second Interaction Location   E0E0 E 1,x 1,y 1,z 1 Known Event quantities: E 0 = Incident  energy Derived Event quantities: E 0 and E 1 => scatter angle  from Compton kinematics x 1, y 1,  z 1 and x 2, y 2,,z 2 => cone axis  E 2,x 2,y 2,z 2 spatial resolution => axis  of the cone  ray Reconstructed  direction : energy resolution => opening angle  LXeGRIT: E. Aprile et al. NIMA 480 (2002)

 emitter … 3  imaging With a Compton telescope and a  emitter … Compton Telescope LL Reconstructed cone: axis , opening angle  E0E0 1 2   - positron range - LOR 2D - Compton Telescope  L related to Which emitter ? Which Compton telescope ? For which performances ?

E  ~ 1 MeV  Only one  No  background  Good for the Compton telescope Ultra fast emission  Very precise time coincidence  Mean  + energy: 632 keV Maximum  + energy: 1474 keV  % A Compton telescope in association with a new radio-medicament Other nuclides could be used, but 44 Sc is the most promising …

44 Sc, 44m Sc and 47 Sc productions at ARRONAX Accelerator for Research in Radiochemistry and Oncology in Nantes Atlantique < Fixed Alpha Deuteron < fixed < Proton Intensity µA Energy MeV Projectile 1 hall for high intensity 1 experimental hall F. Haddad et al., To be published, ND2007 conf. September 2008: first beam 2009 : 44 Sc et 44m Sc production 2010 : 47 Sc production

 + (Line Of Response) measured in a classical micro-PET Liquid xenon Compton telescope 8  8 individual cells (30  30  120 mm 3 ) 240 mm 120 mm Micro-PET (LSO crystals): Transverse FOV:  = 260 mm Axial FOV = 76 mm Rat phantom (water):  = 60 mm Length = 150 mm 148 mm Simulation for the proof of concept with small animal Present: Geant 4, Future: GATE (Subatech joined the collaboration in 2006)  Sc  point source positron range,  + acolinearity isotropic emission for 3 rd  3 rd  -ray measured in the Compton Telescope

Rat phantom 44 Sc  emitter Compton Telescope Micro-PET (LSO crystals) XY slice voxel: 2  2  2 mm 3 Image Rat phantom  + LOR cone  L ~ 2 mm Absolute sensibility on 3 th  > 5% Angular resolution < 2° Maximum Flux per inch 2 ~ 10 4 s -1 Activity in the field of view ~ 1 MBq Keys characteristics for the Compton telescope : Liquid xenon is the good technology

R&D on liquid Xenon Compton telescope

Liquid xenon technology : main physical properties Liquid xenon : Z = 54,  ~ 3 kg/l 95 % Compton 1 MeV Energy deposited in liquid xenon : Both light and charge conversion Intrinsic scintillation due to dimer : 175 nm For 2 kV/cm: Scintillation yield ~ UV/MeV Ionization yield ~ e - /MeV

Cryocooler External cryostat Internal cryostat Prototype for the proof of concept and for the R&D PMT Micromeshes and Anode Liquid xenon Cathode Teflon Entrance window Cryogenic and xenon distribution will be presented by Tom

Liquid Xenon Compton Telescope Principle 3 x 3 cm 2 Micromegas (micromesh + anode) 12 cm Cathode LXe PMT 44 Sc  -ray 1 2 collection of e/i => t 1, E, x, y TPC : z = (t 0 -t 1 ) x v drift UV Z X Y 1 individual cell e- R&D for the TPC read-out … detection of scintillation light => trigger time t 0

R&D on UV detector Amos Breskin et al., NIM A530(2004)258 Gas-AvalancheCharge induction → Choice before end of 2008 Collaboration founded by French Ministry for Foreign Affairs R AL12S-ASSY 27mm 1 inch PMT : HPD : Developed by T.Doke et al. for liquid xenon TOF-PET Under discussion with PHOTONIS-DEP G(Gaseous)PM : In test inside the prototype from June 2007

R&D on ionization detector cathode Conversion anode Ampli 12 cm 50  m t0t0 t0t0 t1t1 t2t2 E1E1 E2E2 Micromesh Spacer  511 keV t0t0 t1t1 t2t2 E1E1 E2E2 (AU) Expected Induced current on anode without amplification  Induced current shape mostly independent of altitude MICROMEGAS Y. Giomataris et al. NIMA376 (1996) → First tests in liquid xenon from June with unsegmented anode to check the liquid xenon purity Associated electronic and anode segmentation : → Compton tracking in 2008 Adaptation of the IDEFIX chip, a low noise charge preamplifier for CdTe device  200 e - noise on (¼ inch) 2 pixel ?

Schedule and Milestones Proof of conceptExpected Achievement 1/ Conception and design 2/ Liquefaction commissioning (next Tom’s talk) 3/ First Signal and safety investigation 4/ Liquid xenon light and charge yield measurement 5/ Compton Tracking 6/ R&D for the TPC read-out July 2007 Oct Feb End April 2007 Decision ~  Imaging dedicated to the Whole-Body and the Public Health, research or industrialization ? Future 3  Imaging on Small Animal at the Ecole Nationale Vétérinaire de Nantes First Image 2009/2010 7/ Conception and design for the Small Animal 8/ Whole Body simulation with GATE 9/ Small Animal camera characterization June 2008 End Small Animal Imaging Submission to FJPPL in 2008 ?