1. MCP PET Simulation (7) – Pixelated X-tal
51.0
(not to scale)
-51.0
51.0 X
Detector geometry, dimension.
Beam energy, position, direction
Properties of LSO
LSO : Decay time 40ns
Lightout : 26,000/MeV
511keV two gammas at the center.
180 deg angle between two gammas.
50mm separation between two modules.
Surface: “groundbackpainted”
(Unified model)
Dimension : 102x102mm
LSO( 1 pixel => 4x4x25mm3)
pixelated into 24x24(left)
Crystal pitch : 4.25mm
MCP
Photocathode embedded in MCP.
Module = LSOs between 2MCPs.

2. Single Electron Responses
Pulse Shape
~500ps rise time(top)
( real measurement by J-F)
similar value for falling time
assume asymmetric gausian shape
2. Average gain factor : 10e6
Single electron gain
~70% in FWHM.
3. Transit Time Spread
sigma = 50ps( real measurement by J-F).
real measurement
Response to single electron
Pulse shape
2.Single electron gain
3.TTS
cf.
Seng’s slides at Picosecond workshop at Lyon08
Simulated pulse shape

3. Readout Scheme
Readout signals from 24 horizontally (vertically) running TLs.
Total 24x2x2 channels for a module.
Position : Anger logic using 5 TLs.
Energy : Sum of two sides( e.g, 5 TL sum w.r.t the maximum for each side)
Timing : Average of maximum Energy TL from each side.
TL direction
Front Side
Back Side

4. Number of p.e.
~1447 p.e for 511keV peak.
# of p.e.

5. Energy resolution 10^6 gain Sum of 5 TL charge. 12.0% FWHM
Event around 511keV
~62% of total events pc

6. CoincidenceTiming resolution
Select event around 511keV peak
~38% efficiency( 0.62*0.62)
10mV threshold LE pickup
375ps FWHM ns

7. Position Measurement Use Anger logic with 5 highest TL’s signal.
Xdet = Sum(Xi*Ei) / Sum(Ei) ( for Vertically running TL in Front)
Ydet = Sum(Yi*Ei)/ Sum(Ei) ( for Horizontally running TL in Back) B C
Reconstructed X coordinate.
Beam Entering Position(X cor)
B : 4.0mm
C : 4.5mm
Photon( Signal) is highly localized
within crystal pitchs( 4.25mm).
Position resol. for coincidence event
~ 2mm
Position reconstruction.
Show results with different beam entering data.

8. Signal Shape at TLs mV ns

9. Plans Depth of Interaction(DOI) Simulation.
Position by time difference.
Validation