P.P. & APD gain ratio report—4 month testing
Ken Chiang, J.Y. Lin, Jeri Chang2009/3/19
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Two kinds of Samples
(photo pentode tubes)
(avalanche photodiodes)
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Schematic Diagrams for APD
)10&()10&(
)300&()300&(_
VdarkVVlightV
VdarkVVlightVRatioGain APD
We use 400V400V for Serial No. AA0705& 450V450V for Serial No. AA0724
•Light Source: Blue LED•Light Intensity: detected by PIN Photodiode simulate very weak light (very simple scale)
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Schematic Diagrams for P.P.
Pentode mode
Diode modediodediode
pentodepentodePP VdarkVVlightV
VdarkVVlightVRatioGain
)100&()100&(
)1000&()1000&(_
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Status of Gain factor of APD
Gain Ratio is temperature sensitive.
2008 2009March
Nov. Dec. Feb. Mar.
Temp.( )℃
23.2~26 18.5~24.6 18.5~26.6 18.4~23.4
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Check temp. vs. Gain ratio of APD2009 Feb. results
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Status of Gain factor of PP
2008 2009
Nov. Dec. Feb. Mar.
Temp.( )℃
23.0~26.4 18.5~24.7 18.5~26.2 18.5~23.3
Gain Ratio is NOT temperature sensitive.
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Output Voltage of APD (HV applied)
2008
2008
2009
2009
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Output Voltage of APD (LV applied)
2008
2008
2009
2009
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Output Voltage of PP (pentode mode)
2008
2008
2009
2009
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Output Voltage of PP (diode mode)
2008
2008
2009
2009
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Next Steps
We will get some more APDs from KEK. (4 pcs of APD made by Hamamatsu.)
One of the APD will be attached on the pure CsI crystal One pure CsI crystal, ~4cm tall, was shipped to Taiwan last week. (2 master students will work on it).
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Simulation for the readout circuit (TINA software)
~10,000 photons are expected to be seen. We use a almost same PCB to measure the high energy cosmic ray before.
Current from APD
Function Generator
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making a 1.5T magnetic field
2 undergraduate students are making a 1.5T magnetic field now.
Because the temperature is too high while we applied current. We are thinking about the other way.
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Summary
The gain ratio of PP and APD samples are under testing for 4 months.
The readout setup for pure CsI crystal+APD is in progress.
We are making a magnetic field in order to understand the effect on PP and APD.
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Backup Slides
Setup picturesMonitoring pictures
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Setup: Outside View
APD
P.P.
Box Size
Setup
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Inside the Box: P.P.
20cmPIN PD
The distance between LED and PP samples is 34cm.
The wave length of blue LED is about 450 nm.
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Inside the Box: APD
20cmPIN PD
The distance between LED and APD samples is 34cm.
The wave length of blue LED is about 450 nm.
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Output Monitoring
VoltageTemperature