Compton Gamma-ray Camera Using a Gaseous TPC and GSO(Ce)- LaBr 3 - PowerPoint PPT Presentation

Compton Gamma-ray Camera Using a Gaseous TPC and GSO(Ce)- LaBr 3 (Ce) Scintillator Pixel Arrays for Astronomy and Medical Imaging Shunsuke KUROSAWA K. Hattori, C. Ida, S. Iwaki, N. Higashi, S. Kabuki, H. Kubo, K. Miuchi, K. Nakamura, H. Nishimura, J. Parker, T. Sawano, A. Takada A , M. Takahashi, T. Tanimori, K. Taniue, K. Ueno Dept. of Physics, Graduate school of Science, Kyoto University, Kyoto, Japan A ISAS / JAXA, Kanagawa, Japan AstroMed09 - Sydney, Australia, 15 December 2009

Contents • Introduction – MeV gamma Astronomy / Medical imaging – Electron-Tracking Compton Camera (ETCC) • Astronomy – Balloon-born experiment (SMILE project) – Imaging of pair-creation process • Medical Imaging – Animal imaging – Proton Therapy • Summary

Sensitivity in X / Gamma-ray Astronomy Observation of MeV gamma-ray keV MeV GeV TeV erg/cm 2 /sec INTEGRAL bad IBIS EGRET 1mCrab sensitivity Air Goal Fermi Cherenkov Astro-H All sky survey ASCA Sensitivity gap good Chandra, XMM in the MeV gamma-ray region ～１°

Medical Imaging (functional image)  New radioactive tracer with new radioisotopes PET : E = 511keV It is possible that SPECT : E < 360keV we obtain various images: anti-body, enzyme, Narrow protein reaction  Multi-radioisotope Imaging With wide energy range Wide dynamic Simultaneous observation of some energy range metabolisms and interactions 139 Ce 133 Ba 131 I 198 Au 22 Na 18 F 54 Mn 65 Zn 60 Co E 167 354 364 412 511 511 835 1116 1173 [keV] 1275 1333 PET SPECT

Electron-Tracking Compton Camera (ETCC) gaseous TPC (time projection chamber) ： [containing  -PIC(MPGD),  GEM (Sauli (1997), Inuzuka et al. (2004)) ] 10cm --- energy and 3-D track of Compton-recoil electron Scintillation camera ： [Pixel array Scintillator] --- energy and position of μ -PIC scattered gamma ray GEM Scintillator  Large FOV (~3str) Reconstruct incident  Kinematical background rejection gamma ray event by event by comparison of two  angles Energy dynamic range: from 0.1 to ~10 MeV

Imaging with ETCC Target Event number 5 Event number 2 Event number 100 Event number 3 Event number 1 Event number 10 Event number 50 Error region (arc) Incident Gamma rays Gaseous TPC Recoil electron (Electron cloud) Scintillator Scattered gamma rays

Vs. Conventional Compton Camera Advanced Our ETCC Conventional COMPTEL Measure DO NOT measure the 3-D track of a Recoil electron the track of a Recoil electron •Reconstruction : point •Reconstruction : circle •Direction error region: arc •Direction error region : donut 15 15 150 events Y [cm] Y [cm] 600 events -15 -15 -15 X [cm] 15 -15 X [cm] 15 137 Cs(1MBq)  2, Advanced Compton 137 Cs(1MBq)  2, Classical Compton

Gaseous Time Projection Chamber (TPC) 3-D electron Drift cage tracking GEM 10cm e -  -PIC 0.4kV / cm 1 GEM Gas gain: ~30,000 0 c  -PIC Position Resolution m (FWHM) ： ~0.4 mm (3-D)  -PIC (micro pixel chamber) X-ray image with  -PIC  2-D gaseous detector: ~ 65,000 pixels 400μm pitch 10cm anode cathode Position resolution:120  m

Position-Sensitive Scintillation Camera GSO(Ce) 8x8 pixels 0.8 Pixel size: 6x6x13mm 3 500 Reflector: ESR TM (3M) 65  m thickness Y-position (a. u) 0.4 400 6 mm 300 0 13mm 200 -0.4 5cm 100 0 137 Cs -0.8 Counts (a. u.) 5cm Multi-anode Photo Multiplier Tube (PMT) HPK H8500 8x8 anodes -0.8 -0.4 0 0.4 0.8 X-position (a. u.) Dynamic energy range: 0.08 -1 MeV Eng. Resolution: 10.5 % @662 keV 2-D image in flood-field irradiation

Astronomy SMILE Project Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment

Schedule (10cm) 3 ETCC (2006) SMILE-1  Operation test of ETCC @ 35km  Measurement of Diffuse cosmic and atmospheric gamma rays ~ 4hours (30cm) 3 ETCC (2011) Observation of Crab or Cyg X-1 ~ 3hours (40cm) 3 ETCC long duration balloon ～ 10days (50cm) 3 ETCC All sky survey Orbiting balloon (~30days) or satellite

SMILE-1 Flight Model  Dynamic energy Range:0.1 – 1 MeV GSO scintillator 3x3PMTs@bottom  Field of view (FOV): 4x(3x2)PMTs@side 3 str (FWHM) (10cm) 3 - (0.15 - 1 MeV) sizeTPC  Efficiency: gas: 1m ~10 -4 @ 0.1-1 MeV Xe(80%)+  Energy resolution Ar(18%)+ C 2 H 6 (2%) (ETCC):~12% 1atm, sealed Electronics @ 662 keV, FWHM  Angular resolution ARM: Incident  Angular ARM: 22 deg. Resolution SPD: SPD: 165 deg. Measure Scatter Plane @ 662 keV, FWHM Deviation Scattered  Recoil electron

SMILE-1 Flight Altitude [km] 32-35km: level flight 4 hours ~3 hours The balloon was Launched on Sep. 1, 2006 @ Sanriku Balloon Center JAXA / ISAS, Japan Launching landing

Energy spectrum diffuse cosmic  atmospheric  rays rays Flux [photons / (cm 2 sec str keV)] Flux [photons / (cm 2 sec str keV (g / cm 2 ))] 10 -2 10 -1 Previous results Previous results 10 -4 10 -3 10 -6 SMILE-1 10 -5 SMILE-1 10 -8 10 -7 We detected 420 photons (Total) @0.15-1 MeV, 32-35 km for 4 hours 10 10 2 10 3 10 4 10 5 10 10 2 10 3 10 4 10 5 [Energy] [Energy]

(30cm) 3 ETCC for SMILE-2 to launch in 2011 40cm TPC 60cm 137 Cs (662 keV) Two source image 54 Mn (835 keV) 137 Cs Scintillator (GSO(Ce)) 54 Mn Energy[keV]

Imaging of Pair-Creation Process 10 MeV μ -PIC GEM Scintillator We detected 10 MeV gamma rays with our camera as pair creation detector using AIST laser-Compton gamma-ray beam Collaborator: H.Toyokawa (Advanced Industrial Science and Technology: AIST, Japan)

Medical imaging Our Camera diagnostic tool Treatment : monitor tool Function imaging Proton therapy Animal imaging Water phantom test

To obtain a higher angular resolution / spatial resolution (  1cm) Angular resolution of the Compton camera depends on the energy resolution of scintillator Incident   φ Angular resolution Angular resolution (FWHM) [degree] GSO array (ARM) Scattering Spatial resolution : Recoil e - angle φ  1 cm (FWHM) Scattered  (detector – target: 15 cm) m e c 2 K cos φ ＝ 1 － ( E + K ) E Sci. Eng. Res. Com. Angular @662keV Res. @662keV (Ce) :  E/E~ 3 % 4.2  10.5 % LaBr 3 2.1  3% @ 662 keV (FWHM) Loef et al . (2001)

Assembly of LaBr 3 (Ce) array Using our technique, 133 Ba GSO monolithic we assembled an 8  8 array. LaBr 3 monolithic  E/E = 4.1  0.1 % @ 356 keV (FWHM) GSO array 6.1 mm pitch (=multi-anode PMT LaBr 3 H8500 anode pitch) array 54mm 20mm GSO FWHM(%)= (10.4  0.3)  (E/662keV) -0.51  0.01 LaBr 3 ： hygroscopic LaBr 3 FWHM(%)= Hermetic package (5.7  0.4)  (E/662keV) - 0.53  0.01

Setup of ETCC Source 2m LaBr 3 (Ce) arrays Gaseous TPC (10cm) 3 (576 pixels) Angular resolution [deg.] @662 keV (FWHM) GSO : 6.4 ± 0.2 LaBr 3 : 4.2 ± 0.3 Spatial resolution : ~1cm

Mouse (small animal) imaging 65 Zn 2+ (1116keV) 131 I-MIBG (365keV) Imaging (ETCC & CT) Imaging (ETCC & photo) Collaborator: H. Kimura, H. Amano, H. Saji, (Kyoto Univ., Japan)

131 I-MIBG (365keV) & 18 F-FDG (511keV) simultaneous imaging Collaborator: H. Kimura, H. Amano, H. Saji, (Kyoto Univ., Japan)

Rabbit (medium-sized) imaging Collaborator: H. Kimura, H. Amano, H. Saji, (Kyoto Univ., Japan)

Dual head Compton Camera Scintillator TPC Target TPC 20cm Scintillator 3-D image: 133 Ba source

Proton Therapy Attack on Cancerous cells 200MeV Monitoring 150MeV proton Before treatment: ionization chamber After treatment: PET technique (PET: positron emission tomography) Depth in Tissue (water) [mm] Real time : none Simulation study Gamma ETCC : rays  ability to detect Prompt gamma proton rays as the monitor  Wide energy range (0.1-10 MeV) Water phantom neutron  Rejection of Neutron  Wide field of view (~3 str.)

Proton Therapy Attack on Cancerous cells 200MeV Monitoring 150MeV proton Before treatment: ionization chamber After treatment: PET technique (PET: positron emission tomography) Depth in Tissue (water) [mm] Real time : none Simulation study Simulation Gamma ETCC : 511keV 2.2MeV rays  ability to detect Prompt gamma proton Gamma rays rays as the monitor  Wide energy range (0.1-10 MeV) neutron Water phantom neutron  Rejection of Neutron  Wide field of view (~3 str.)

We are developing a monitor for Proton Therapy ETCC 160 MeV Proton (10cm) 3 TPC Water Phantom collaborator : J. Kim (Research Institute and Hospital, 30cm National Cancer Center, Korea) Experiment in Osaka Univ. Research Center for Nuclear Physics (RCNP)

Summary • We have developed Electron-Tracking Compton Camera • For Astronomy: – SMILE-1 (10cm) 3 TPC + GSO(Ce) array We measured the cosmic / atmospheric gamma rays – SMILE-2 (30cm) 3 TPC + GSO(Ce) array We are optimizing the gas mixture and pressure, and developing the detector for SMILE-2 (2011, launch !) – Pair creation mode at ~ 10 MeV • For Medical Imaging: – animal imaging (10cm) 3 TPC (Ar(90%) C 2 H 6 (10%) 1atm) + LaBr 3 (Ce)array FWHM angular resolution 4.2 ± 0.3 deg. at 662 keV – Proton therapy Real time monitor of prompt gamma rays to measure the Bragg-peak position

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