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FS Detector. 2002/05/21@Huntsville. H.M.Shimizu. Old Baseline. 45%. R7600-M64. small insensitive area. R7600-03-M64. baseline choice at the beginning of Phase-A. Sensitive area is 45% of its physical dimension distributed in the central region of the device. Weight = 28.8g / PMT
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FS Detector 2002/05/21@Huntsville H.M.Shimizu
Old Baseline 45% R7600-M64 small insensitive area R7600-03-M64 baseline choice at the beginning of Phase-A Sensitive area is 45% of its physical dimension distributed in the central region of the device. Weight = 28.8g / PMT Gain = 1x106 @ -900V
Optical Adaptor for Old Baseline (90%) Insensitive area can be removed by employing additional optical adaptors which demagnify the images on the focal surface on to the sensitive area of photomultipliers. R7600-M64 + Optical Adaptor 75% 65%
Present Baseline More direct solution has been introduced. R8900-03-M36 (M25/M16) current baseline choice Sensitive area is increased 83% of its physical dimension. The sensitive area can be increased up to 95% by attaching a simple optical adaptor (tapered glass or reflector). Weight = 26.7g / PMT Gain = 2x106 @ -900V Weight = 26.0g / PMT Gain = 4x106 @ -900V Weight = 27.3g / PMT Gain = 2x106 @ -900V 83% 95%
R8900-03-M36 R8900-03-M36 ZA1114 Gain Map Sum Individual Anodes readout electronics connection fault UV-window weight = 27.3g gain = 2x106 (@-900V)
Next(?) Baseline Further improvement is in progress. (R8400-00-M256) Sensitive area is increased 90% of its physical dimension. The device weight is further reduced. Only borosilicate window versions are available. 89% Weight = 77g (=4x19.3g) Gain = 5x105 @ -900V Realization of R8400-03-M256/M144 requires additional development of fabrication techniques. (test fabrication scheduled in Jun. 2003)
Comparison of Tile-shape Multianode Photomultipliers under consideration Hamamatsu Flatpanel (Metal-channel Multianode Photomultipliers) Burle Planacon (Microchannel Plate Photomultiplier) Dynode Metal Channel Microchannel Plate < 1:1.5 Uniformity < 1:3 Electron Collection Efficiency ~ 70 % ~ 60 % HV for the gain of 106 1000 V 2900 V 3 mm 6 mm Pixel Size Available at this moment
FS Detector Candidates Bialkali Photocathode 12-stage Metal Channel Dynodes Hamamatsu Photonics R7600-M64 device dimension = 25.7 mm x 25.7 mm anode format=8x8 FS pixel size = 3.3mm Asens/Adevice = 45% anode crosstalk = 3% Weight = 28.8g / PMT Gain = 1x106 @ -900V B < 0.8 mT uniformity = 1:3 device dimension = 25.7 mm x 25.7 mm (26.2 mm x 26.2 mm) R8900-M36 anode format=6x6 FS pixel size = 4.5mm Asens/Adevice = 83% Weight = 27.3g Gain = 2x106 (@-900V) anode crosstalk = 7% B < 0.2 mT uniformity = 1:3 R8400-M256 device dimension = 52 mm x 52 mm anode format=16x16 FS pixel size = 3.3mm Asens/Adevice = 89% Weight = 77g (=4x19.3g) Gain = 5x105 @ -900V (uniformity = 1:2?)
Systematics Relation between Physics Requirements and Instrument Requirements anode cross-talk 7% Dj ~ 0.4 deg increase of angular uncertainty (30% Dj ~ 0.9 deg) DEth ~ 1% increase of threshold energy (for E=1020eV 60o) D E / E ~ ±0.1 De /e ~ ±0.1 D Eth / Eth ~ +0.1 -0.2 e(MAPMT) DT = ±25oC Gain Change = accuracy of front-end-comparator and HV D Vth / Vth = 50% D HV = 23 V (for HV=-900V)
Threshold Energy D log10(Ethreshold) ~ - 5.3 De(FS) Ethreshold is defined as the energy where the triggering efficiency is 50%. D log10(Ethreshold) Np.e.≥6 continuously for 5 GTU 10% relative change of quantum efficiency De(FS) ≤ 0.012 ~ 0.1*e(FS) Np.e.≥3 continuously for 5 GTU corresponds to 0.06 change in D log10(Ethreshold) e(FS) Ethreshold 0.132 3.5 x 1019 eV 0.12 4 x 1019 eV e(FS) 0.108 4.7 x 1019 eV De(FS) / e(FS) ≤ 0.1 |D log10(Ethreshold) | ≤ 0.064 |DT| ≤ 25oC
e(MAPMT) = S Npulse Nphoton V≥Vth Npulse R8900 Allowable Misadjustment of HV and Front-end-comparator nominal threshold setting single photoelectron peak x = 1/3 V=V0 a ~ -7 a = De(MAPMT) / Dx * 100 V Vth = V0 / 3 nominal threshold setting x = Vth / V0 a is the measure of influence to e(MAPMT) of misadjustment of comparator level and also of high voltage
nominal threshold setting x = 1/3 5 ≤ |a| ≤ 8.5 a = De(MAPMT) / Dx * 100 x = Vth / V0 Allowable Misadjustment of HV and Front-end-comparator R8900 (M16)
Allowable Misadjustment of HV and Front-end-comparator In case we require |De(MAPMT)| ≤ 0.015 ~ 0.1*e(MAPMT) Allowable Misadjustment of Front-end-comparator 5 ≤ |a| ≤ 8.5 Dx ≤ 0.17 Dx / x ≤ 0.5 x must be larger than the noise level. x can be as large as 0.5. Allowable Misadjustment of HV a = De(MAPMT) / Dx * 100 Dx / DHV = 0.0076 @HV=-900V 5 ≤ |a| ≤ 8.5 DHV ≤ 23 V @HV=-900V DHV / HV ≤ 0.025
Further Development Enhancement of Quantum Efficiency of GaAsP PMTin near UV regionusing Wavelength-shifter and Dichroic Mirror
Single Crystal Photocathode High Quantum Efficiency in l > 400nm photon photoelectron
Recover UV Sensitivity (1) Development of New Fabrication Process crystal growth with negligibly thin buffer layer crystal growth without buffer layer (2) Additional Wavelength-shifting Layer UV escaping visible UV visible photoelectron
UV UV-transparentvisible-reflective visible photoelectron Wavelength-shifter + Dichroic Mirror Jpn. Patent Pending No.2000-399940 The dichroic mirror must haveexcellent wavelength selectivity at l=400nmfor incident angles of 0-30 degrees.
high quantum efficiency line-up first trial in Aug. 2003 Pixel Size bialkali Development of Multianode Photomultipliers for EUSO 7mm R8900-M16 R8400-M64 R7600-M16 (+optical adaptor) 6mm R8900-M25 (R8400-M100) 5mm Dec.2002 R8900-M36 (R8400-M144) 4mm R8400-M256 Jun. 2003 3mm R7600-M64 (+optical adaptor) 5% 10% 15% 20% FS Efficiency
Time-scale of R&D of New Devices 1. UV-window version of R8400-M256 check if we lose the transparency of entrance window due to the heat during its attaching process test fabrication is scheduled in Jun. 2003 2. Multianode GaAsP Photomultipliers trial fabrication is scheduled in Aug. 2003 (?) incomplete compatibilities with existing models Does it function ? Sensitive area may not be maximum Is the life time sufficiently long for data accumulation? Can we successfully achieve good UV sensitivity?
x = 1/3 a = De(MAPMT) / Dx -13 ≤ a ≤ -6 x = V / V0 Allowable Misadjustment of HV and Front-end-comparator | De(MAPMT) | ≤ 0.015 Dx ≤ 0.2 Dx / DHV = 0.0076 @HV=-900V | De(MAPMT) | ≤ 0.015 Dx / DHV = 0.0076 @HV=-900V