DRD6 Liquid xenon detector technology 3 g Medical

D_R&D_6 Liquid xenon detector technology 3 g 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 Workshop FJPPL’ 07, 9 -12 May 2007, KEK, Japan

1. 3 g Medical Imaging : concept and motivation 2. 44 Sc production at ARRONAX 3. Simulation and expected results with liquid xenon telescope 4. Liquid xenon technology 5. Expected schedule and Milestones

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

Positron Emission Tomography with + emitters + disintegration L Main incertitude on the emitter position : LOR length Human body Rat body L ~ 30 cm ~ 6 cm TOF-PET (260 ps) L ~ 9 cm LOR 2 D 5 mm 1 mm T. Doke et al. NIMA 569 (2006) Sub-centimetre precision along the LOR achievable ?

Single detection with a Compton telescope ray Known Event quantities: E 0 = Incident energy Measured Event quantities: E 0 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 E 1, x 1, y 1, z 1 Derived Event quantities: E 0 and E 1 => scatter angle from Compton kinematics E 2, x 2, y 2, z 2 x 1, y 1, z 1 and x 2, y 2, , z 2=> cone axis Reconstructed direction: spatial resolution => axis of the cone energy resolution => opening angle LXe. GRIT: E. Aprile et al. NIMA 480 (2002)

… 3 imaging With a Compton telescope and a 3 emitter … 3 emitter L Reconstructed cone: axis , opening angle E 0 L related to Compton Telescope - positron range - LOR 2 D - Compton Telescope Which emitter ? Which Compton telescope ? 1 2 For which performances ?

A Compton telescope in association with a new radio-medicament + 94. 3 % E ~ 1 Me. V Only one Good for the Compton telescope No background Ultra fast emission Very precise time coincidence Mean + energy: 632 ke. V Maximum + energy: 1474 ke. V Other nuclides could be used, but 44 Sc is the most promising …

44 Sc, 44 m. Sc and 47 Sc productions at ARRONAX Accelerator for Research in Radiochemistry and Oncology in Nantes Atlantique Projectile Energy Me. V Intensity µA Proton 30 - 70 < 350 35 - fixed < 50 Deuteron 15 - 35 50 Alpha 70 - Fixed < 35 • 1 hall for high intensity • 1 experimental hall F. Haddad et al. , To be published, ND 2007 conf. September 2008: first beam 2009 : 44 Sc et 44 m. Sc production 2010 : 47 Sc production

Simulation for the proof of concept with small animal Present: Geant 4, Future: GATE (Subatech joined the collaboration in 2006) Liquid xenon Compton telescope 44 Sc point 8 8 individual cells (30 30 120 mm 3) source positron range, + acolinearity isotropic emission for 3 rd 120 mm Rat phantom (water): f= 60 mm Length = 150 mm Micro-PET (LSO crystals): Transverse FOV: = 260 mm Axial FOV = 76 mm 240 mm 148 mm + (Line Of Response) measured in a classical micro-PET 3 rd -ray measured in the Compton Telescope

44 Sc emitter Image Compton Telescope cone Micro-PET (LSO crystals) Rat phantom + LOR L ~ 2 mm XY slice Keys characteristics for the Compton telescope : Absolute sensibility on 3 th > 5% Angular resolution < 2° Maximum Flux per inch 2 ~ 104 s-1 Activity in the field of view ~ 1 MBq Liquid xenon is the good technology voxel: 2 2 2 mm 3

R&D on liquid Xenon Compton telescope

Liquid xenon technology : main physical properties Liquid xenon : Z = 54, r ~ 3 kg/l 95 % Compton Interaction @ 1 Me. V Energy deposited in liquid xenon : Both light and charge conversion Intrinsic scintillation due to dimer : 175 nm For @ 2 k. V/cm: Scintillation yield ~ 17000 UV/Me. V Ionization yield ~ 55000 e-/Me. V

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

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

R&D on UV detector G(Gaseous)PM : 1 inch PMT : Collaboration founded by French Ministry for Foreign Affairs 27 mm Developed by T. Doke et al. for liquid xenon TOF-PET R 5900 -06 AL 12 S-ASSY In test inside the prototype from June 2007 HPD : Gas-Avalanche Charge induction Amos Breskin et al. , NIM A 530(2004)258 Under discussion with PHOTONIS-DEP → Choice before end of 2008

R&D on ionization detector MICROMEGAS Y. Giomataris et al. NIMA 376 (1996) 511 ke. V Micromesh Spacer anode t 0 E 2 Conversion (AU) cathode t 0 t 1 Expected Induced current on anode without amplification 12 cm E 1 t 2 Ampli E 1 50 mm t 0 t 1 E 2 t 2 Induced current shape mostly independent of altitude → First tests in liquid xenon from June with unsegmented anode to check the liquid xenon purity Associated electronic and anode segmentation : Adaptation of the IDEFIX chip, a low noise charge preamplifier for Cd. Te device 200 e- noise on (¼ inch)2 pixel ? → Compton tracking in 2008

Schedule and Milestones Proof of concept Expected 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 2006 April 2007 Small Animal Imaging July 2007 Oct. 2007 Feb. 2008 End 2008 Submission to FJPPL in 2008 ? 7/ Conception and design for the Small Animal 8/ Whole Body simulation with GATE 9/ Small Animal camera characterization 3 Imaging on Small Animal at the Ecole Nationale Vétérinaire de Nantes June 2008 End 2008 2009 First Image 2009/2010 Future 3 Imaging dedicated to the Whole-Body and the Public Health, research or industrialization ? Decision ~ 2010