1 Geant4 Simulation :MCP PET 4’’(102mm) Scintillator ( LSO) 4’’(102mm) 10mm Glass( Borosilicate) PhotocathodeI(Carbon) Space(Vacuum) MCP(Alumina) Space(Vacumm) Trans-Line(Gold) Isolator(Alumina) Ground(Copper) Scintillator MCP Assembly 0.060’’ 0.002’’ 0.040’’ 0.200’’ 0.040’’ 0.035mm 0.400mm 0.025mm Air Gap 0.001’’ 9.15mm

2 Simulation Setup 113.2mm 28.3mm 102mm(4’’) 511keV 2 gamma 50mm Scintillator : LSO, LaBr3

3 # of photoelectron at photo-cathode # of p.e at 1 st layer Sum of 2 sides( front and back) 371 for LSO 976 for LaBr3( ~2.6 times larger than LSO) LaBr3 has more compton scattering events. # of p.e ( LSO) LaBr3

4 Single Electron Responses 1.Pulse Shape ~500ps rise time(top) ( real measurement by J-F, 18 p.e) 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. Simulated pulse shape real measurement

5 Readout Scheme TL direction Front Side( -> Extract X cor)Back Side(-> Extract Y cor) Readout signals from 24 horizontally (vertically) running TLs. TL : 4mm width, 4.25mm pitch. Total 384(24 TL x 2 ends/TL x 2 sides x 4layers) channels for a module. Position : 5 TL energy weight Energy : Sum of two sides( e.g, 5 TL sum w.r.t the maximum for each side) Timing : Average of maximum TL from each side.

6 Sample pulses(LaBr3) TL#7TL#8TL#9 TL#10 TL#11TL#12 TL#13TL#14TL#15 Layer#0 Front side One end. # of p.e = 259 Beam: Middle of TL#11 & TL#12 mV ns

7 Pulse( close-up) ( LaBr3) mV ns TL#11TL#12

8 Energy resolution(LaBr3) pC Sum of 5 TLs ( around the maximum) Integrated Charge. 10^6 gain 50ohm termination. ~24% of effi. Around 511keV peak. ( > 130pC) ~9% FWHM Energy resol. at 511keV.

9 Position(LaBr3) A) X = 0mmB) X = 2.125mmC) X = 4.25mm Recon. X(peak)0.05mm2.14mm4.24mm A) Beam X = 0mm B) Beam X = 2.125mmC) Beam X = 4.25mm Position : Energy weighted of 5 TLs (w.r.t the maximum energy TL.)

10 Coincidence Timing resolution(LaBr3) Event time: Average of 4 timing 1. Finid first non-zero signal layer. 2. Find maximum signal TL. 3. Apply 5mV threshold, Leading Edge. Top: ~1ns FWHM ( ~62% eff.) Before energy cut Bottom : 375ps FWHM ( 6.7% eff.) Select the event around 511keV energy. Energy > 130( pC)

11 Summary 1.Four layers of MCPs+Scintillator 2.Continuous Scintillator( 4’’x4’’) ( LaBr3, LSO) mm pitch ( ) of TLs. 4. Energy : ~9% at 511keV CoincidenceTiming : ~375ps ( ~7% effi.)

12 Backup: Pulse shape( LSO) Layer#0 Front side One end. # of p.e = 90 Beam: Middle of TL#11 & TL#12