R. Pani Department of Experimental Medicine and Pathology University of Rome La Sapienza-Italy. Flat Panel PMT: advances in position sensitive photodetection 8th Topical Seminar on Innovative Particle and Radiation Detectors October 2002 Siena, Italy

Metal channel dynode PSPMT Flat Panel H inch Final goal

Large FoV PSPMT Packing density (effective area/outer size) (%) 5 inch1 inch R76002 inch Flat_ panel cm FoV or more

Parameter Flat Panel 1 Flat Panel 2 3” R24865” R3292 R5900 M64 R7600 C8/C12 Window thickness (mm) Dynode structure Metal channel Metal channel Proximity mesh Proximity mesh Metal channel Metal channel Dynode number of stage12 11 Anode structureMulti anode Crossed wire Multi anode Crossed wire Number of anodes64 (8x8) (8x8)4+4/6+6 Pixel size/ pitch (mm)5.6/ /2.255/5.5/3.6 Effective area (mm 2 )49x49 50 diam100 diam18.1x18.122x22 Outer size (mm 2 )53x5352x5276 diam132 diam26x26 PMT thickness (mm) Intr. charge spread (mm)<1 FWHM ? 7 FWHM11 FWHM<1 FWHM Packing density (effective area/outer size) (%) Cathode luminous sensitivity (  A/Lm) Gain Anode dark current (nA) Time response transit time (ns) 6617?55 Anode uniformity1:31:21:4 1:51:4

Inter-Channel Gain Variation Flat 1 Flat P1-1 P1-8P8-8 P P1-1 P1-8P8-8 P : : 100

Flat_panel CsI(Tl) scintillating array 16x16 array 1.4x1.4 mm 2 pixel size 15x15 array 3x3 mm 2 pixel size 48 mm 57 Co flood field irradiation S.R.= 0,63 mm FWHM S.R.= 0.72 mm FWHM 26 mm

24x24 array 1.8x1.8 mm 2 pixel size NaI(Tl) scintillating array 57 Co flood field irradiation Anode disconnected 48 mm Flat 1 Flat 2

NaI(Tl) scintillating array 24x24 array 1.8x1.8 mm 2 pixel size 57 Co flood field irradiation 48 mm R7600-C12 (1 inch)R3292 (5inch)

NaI scintillating array : Best energy resolution values Co 57 spot irradiation Flat Panel %12,1 % R3292 (5 inch)R7600-C12 (one inch) Flat Panel 2 10,4 %

Flat 1 Flat 2 Position linearity Flat panel PMT /NaI(Tl) scintillation array

Light spot scanning Readout Electronics Light pulser Flat panel PMT Optical Fiber  1mm

6,5mm6mm Maximum light spread 3,5 mm FWHM 1,2mm Light Spot Scanning PMT Boundary Response

Anode Crosstalk ,21,80,2- -1,81002,7- -0,22,60, Hamamatsu data Anode 37 Measured value <0,1<0,8<0,1- -<1,4100<2,4- -<0,1<1,8<0, Anodes 7 phe

(Max-min)/max = 13% Spot scanning positions 1 st metal channel dynode Intra-Anode Gain Variation Maximum light spread 3,5 mm FWHM 1,2mm 1mm

Anode 45 Anode 37 Light spot distribution evaluation Maximum light spread 3,5 mm FWHM 1,2mm 0,5 mm interspace

FWHM = 1,2 mm Light spot distribution evaluation Fiber-photocathode distance = 2mm (glass window) 1 mm diameter Fiber Photoelectrons number = 7 Single Anode Scanning Total Charge Collected Missing Charge

Position determination by light distribution centroide method Anger camera principle DRF = Detector Response Function P(x,y) = PSPMT gain uniformity response Spatial resolution = Standard error of the mean value

Light Spot Distribution Anodes FWHM <5 mm FWHM 7 mm FWHM 10 mm FWHM 13 mm 11 phe

11Phe PSF 16mm FWHM Spatial resolution vs high voltage

Light spot irradiation Light spot FWHM=16 mm Position distribution Pulse height distributions Anodes S.R. 2 mm S.R. 1,1 mm

Spatial resolution vs energy resolution Light PSF 16mm FWHM Phe 60

PSF vs Spatial Resolution 11 Phe

FWHM 6 mm FWHM 7 mm FWHM 5 mm FWHM 4 mm Light Sampling and Position Linearity 2mm step scanning Anode 6 mm