XEMIS: L IQUID X ENON C OMPTON C AMERA FOR 3 γ I MAGING Yajing XING, IMT Atlantique 23 May 2017 @Beijing, China
XEMIS: XEnon Medical Imaging System Motivation: Personalized Medicine ↪ Concept: Low activity medical imaging ↪ Principles: 3 γ imaging & Liquid xenon Compton camera XEMIS1 XEMIS2 XEMIS3 R&D Total-body imaging Small animal imaging LXe clinical camera Neurology: ∼ 250 kg Paediatrics: ∼ 700-800 kg Whole body: few tons 30 kg 200 kg 2 May 22, 2017 Yajing XING -TIPP2017@Beijing
Outline PTR Liquefaction 3 γ imaging technique • Heat exchanger Purification XEMIS1 XEMIS1: R&D prototype • DAQ Storage Cryostat Getters XEMIS2: small animal imaging • ReStoX XEMIS2 Purification Summary • 3 May 22, 2017 Yajing XING -TIPP2017@Beijing
Principle of the 3γ Compton Imaging - Direct 3D location of the radioactive source ⚀ Radioisotope (β + ,γ) emitter in quasi-coincidence: - Administered activity reduction &/or shorter scan times β + (E max = 1.472 MeV) ↪ 44 Sc M2 (x 2 , y 2 , z 2 ) γ (E 0 = 1.157 MeV) T 1/2 = 4 h 𝛿 511𝑙𝑓𝑊 M1 (E 1 , x 1 , y 1 , z 1 ) ⚁ Position of the source: LOR ↪ Line of Response (LOR) & Compton Cone Compton ⚂ γ direction reconstruction : Telescope 𝜾 ↪ Compton kinematics ∆ ↪ Spatial Resolution ↪ Axis of the cone ∆ Energy Resolution 𝛿 511𝑙𝑓𝑊 ↪ Opening angle Compton cone 4 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMiS1: R&D prototype LXeTime Projection Chamber (TPC) Principle 30 kg LXe PhotomultiplierTubes 𝒖 𝟏 12 cm drift TPC Field ring (23) PMT Scintillation signal LXe Homogeneous 1” V UV VUV detection by PMT drift field sensitive ↪ ƴ −Xe Interaction Time 𝒖 𝟏 up to 2.5 kV/cm VUV 𝑭 𝒆𝒔𝒋𝒈𝒖 Ionization signal Charges transport & collection ↪ Drift time 𝑢 1 e - e - ↪ Energy E ∝ 𝑂 𝑓 ↪ (𝑦, 𝑧) ⟹ Interaction vertex (𝑦, 𝑧, 𝑨, 𝐹) 𝑭 𝒉𝒔𝒋𝒆 Segmented anode Frisch Grid 𝒖 𝟑 𝒖 𝟐 (2.5 x 2.5 cm 2 active) in 64 pixels 500LPI 125 μm 5 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS1: Ionization Signal Readout ID IDeF-X X Asic ics y Io Ioniz izatio ion sig ignals ls of f 64 p pix ixels ls Developed for CdTe @ IrFU (Gevin et al. 2006) Adapted by Subatech for LXe Even reconstruction Compton scattering @511 keV Anode 64 pixels In LXe .1 mm 2 3.1 .1 x x 3.1 Ultra-low noise front-end electronics Noise < 100 e - (at LXe Temp) x 511 keV (@1 kV/cm) ⇒ 27200 e‐ 6 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS1: Ionization results@511 keV (1 kV/cm) MC simulation of primary electron trajectory LXe 511keV electrons ↓ Drift time resolution: ∼ 50 ns DOI resolution: ∼ 100 μm ∼ 100 μm for 511 keV Beginning 1𝑛𝑛 𝑂𝑓 𝑛𝑓𝑏𝑡𝑣𝑠𝑓𝑒 𝑂𝑓 𝑗𝑝𝑜𝑗𝑨𝑓𝑒 Frisch Grid 𝐻𝑠𝑗𝑒 γ 𝐻𝑠𝑗𝑒 End 𝐵𝑜𝑝𝑒𝑓 𝐵𝑜𝑝𝑒𝑓 𝑨 (𝑛𝑛) 7 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS1: Ionization results @511 keV Resolution along the LOR Attenuation length > 1 m 0.75 kV/cm α Gallego et al., NIMA (2015) Equivalent to ΔL = 8.2 mm (FWHM) for a 5 cm distant source σ(E) = 4.92 ± 0.04 % E • Angular resolution limited by active area of XEMIS1 • XEMIS2 is the key Motivation! 8 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS2: Small animal imaging Camera ReStoX LXeTPC Camera Purification Active volume - axial : 2 x 12 cm - radius: 7 -> 19 cm LXe LX Air ir High Purity LXe 12 120mm 12 120mm at 1.2 bar (168 K) LXe: 200 kg Vacuum Fiducial volume ∼ 24 L Ionization Scintillation 2 x 10 4 3.1x3.1 mm 2 64 x 1’’ PMTs in LXE pixels with ultra-low covering 16 sectors in f noise cold FEE 9 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS2: Complete simulation with Geant4 Detectable Event Fraction Quite uniform response of the detector! PMTs Phantom length Phantom radius Mouse Phantom XEMIS2 expected image 20 kBq, 20 mns Cathode Simulated true distribution Reconstructed image Anodes 44Sc Total: 20.0 kBq Hot Sphere: 0.5 kBq 10 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS2: cryogenic commissioning ReStoX : Re covery and Sto rage system of X enon Xenon cryogenics of XEMIS2 : Installation in HOSPITAL ✓ powerfull (up to 10 kW) ✓ compact (210 kg capacity) ✓ ultra clean (ppb impurities lvl) ✓ safe (from RT to -110°C) Xenon temperature (K) Without LN2, RT would be reached in ~ 1 year 11 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS2: cryogenic commissioning Assisted Gravity Recovering Equivalent to 732 kg/h Differential pressure First LXe recovery in 10 minutes! 12 May 22, 2017 Yajing XING -TIPP2017@Beijing
XEMIS2: DAQ for Ionization IDeF-X HD LXe Challenge: continuous read-out with negligible dead-time I maging De tector F ront-end Goal : record on disc 10 4 charge and time signals/pixel/s IRFU - SUBATECH 20480 pixels 640 IDeF-X 640 XTRACT 80 PU 6 FPGA X 8 X 8 8 x 32A IDEF-X XTRAC 2A+1D IDEF-X XTRAC PU X 32 IDeF-X XTRACT X 32 X 32 MICHRAU - SUBATECH X 8 X 8 LVDS XTRACT 8 x 32A 2A+1D IDEF-X XTRAC X emis T PC R eadout for IDEF-X XTRAC PU X 32 IDeF-X XTRACT X 32 X 32 A cquisition of C harge and T ime x6 > 2m X 8 X 8 FPGA 8 x 32A IDEF-X XTRAC 2A+1D IDEF-X XTRAC PU X 32 IDeF-X XTRACT X 32 Board X 32 T Operating T XTRACT = -80 °C T PU = -30 °C T IDeF-X = -100 °C T FPGA = 25 °C P Heat ( 40W) 500mW/PU (32W) 50mW/chip (32W) 50mW/Chip 13 May 22, 2017 Yajing XING -TIPP2017@Beijing
Conclusions ✓ 3 γ imaging will be a new medical modality thanks to LXe ✓ It involves lots of technologies and innovations for the camera design ✓ XEMIS covers initial TRLs inside a scope compatible with Fundamental Research frame ✓ Expected image qualities are very promising: - very low activity in the FOV - good spatial resolution in all the FOV - fast scan of all the FOV ★ XEMIS2: The first LXe camera will be installed in a hospital ★ LXe technology is scalable: design of large total-body camera could be investigated. 14 May 22, 2017 Yajing XING -TIPP2017@Beijing
CIMA Thank you for your listening Any questions?
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