D_R&D_6 Liquid xenon detector technology

Workshop FJPPL’07, 9-12 May 2007, KEK, Japan

3 Medical Imaging with liquid xenon and 44Sc

Eric Morteau, Patrick Le Ray, Cyril GrignonNoel Servagent, Jean-Pierre CussonneauDominique Thers(Nantes)

Tom Haruyama (KEK)

Wednesday, 09 May 2007

1. 3 Medical Imaging : concept and motivation

2. 44Sc 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

Main incertitude on the emitter position : LOR length

1 mm5 mmLOR2D

~ 6 cm~ 30 cmL

Rat bodyHuman bodyTOF-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:

E1 = Energy lost by the scattered electron at the first hitx1,y1,z1 = First Interaction Location x2,y2,z2 = Second Interaction Location

E0

E1,x1,y1,z1

Known Event quantities:

E0 = Incident energy

Derived Event quantities:

E0 and E1 => scatter angle from Compton kinematics

x1, y1, z1 and x2, y2,,z2=> cone axis

)E(EE

Emc=θ 2

100

1 1cos

E2,x2,y2,z2

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

LReconstructed cone:axis , opening angle

E0

1

2

- positron range- LOR2D - 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 keVMaximum + energy: 1474 keV

+ 94.3 %

A Compton telescope in association with a new radio-medicament

Other nuclides could be used, but 44Sc is the most promising …

44Sc, 44mSc and 47Sc productions at ARRONAXAccelerator for Research in Radiochemistry and Oncology in Nantes Atlantique

< 3570 - Fixed Alpha

5015 - 35Deuteron

< 5035 - fixed

< 35030 - 70Proton

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 beam2009 : 44Sc et 44mSc production

2010 : 47Sc production

+ (Line Of Response) measured in a classical micro-PET

Liquid xenon Compton telescope 88 individual cells (3030120 mm3)

240 mm

240 mm120 mm

Micro-PET (LSO crystals): Transverse FOV: = 260 mmAxial FOV = 76 mm

Rat phantom (water): = 60 mmLength = 150 mm

148 mm

Simulation for the proof of concept with small animalPresent: Geant 4, Future: GATE (Subatech joined the collaboration in 2006)

Scpoint sourcepositron range, + acolinearity

isotropic emission for 3rd

3rd -ray measured in the Compton Telescope

Rat phantom

44Sc emitter

Compton Telescope

Micro-PET (LSO crystals)

XY slice

voxel: 222 mm3

Image

Rat phantom

+ LOR

cone

L ~ 2 mm

Absolute sensibility on 3th > 5%Angular resolution < 2° Maximum Flux per inch2 ~ 104 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 Interaction @ 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 ~ 17000 UV/MeV Ionization yield ~ 55000 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 cm2

Micromegas(micromesh +

anode)

12 cm

Cathode

LXe

PMT

44Sc -ray

1122

collection of e/i=> t1, E, x, y

TPC :z = (t0-t1) x vdrift

E UV

Z

XY

1 individual cell

e-

R&D for the TPC read-out …

detection of scintillation light => trigger time t0

R&D on UV detector

Amos Breskin et al., NIM A530(2004)258

Gas-Avalanche Charge induction

→ Choice before end of 2008

Collaboration founded by French Ministry for Foreign Affairs

R5900-06AL12S-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

t0

t0

t1 t2

E1

E2

Micromesh

Spacer

511 keV

t0 t1 t2

E1 E2

(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 concept Expected Achievement

1/ Conception and design 2/ Liquefaction commissioning (next Tom’s talk)3/ First Signal and safety investigation4/ Liquid xenon light and charge yield measurement5/ Compton Tracking6/ R&D for the TPC read-out

July 2007Oct. 2007Feb. 2008End 2008

2006April 2007

Decision ~ 2010

3 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 Image2009/2010

7/ Conception and design for the Small Animal8/ Whole Body simulation with GATE9/ Small Animal camera characterization

June 2008End 2008

2009

Small Animal Imaging Submission to FJPPL in 2008 ?