P.P. & APD gain ratio report—4 month testing

Ken Chiang, J.Y. Lin, Jeri Chang2009/3/19

Super Belle Meeting 2

Two kinds of Samples

(photo pentode tubes)

(avalanche photodiodes)

Super Belle Meeting 3

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)

Super Belle Meeting 4

Schematic Diagrams for P.P.

Pentode mode

Diode modediodediode

pentodepentodePP VdarkVVlightV

VdarkVVlightVRatioGain

)100&()100&(

)1000&()1000&(_

Super Belle Meeting 5

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

Super Belle Meeting 6

Check temp. vs. Gain ratio of APD2009 Feb. results

Super Belle Meeting 7

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.

Super Belle Meeting 8

Output Voltage of APD (HV applied)

2008

2008

2009

2009

Super Belle Meeting 9

Output Voltage of APD (LV applied)

2008

2008

2009

2009

Super Belle Meeting 10

Output Voltage of PP (pentode mode)

2008

2008

2009

2009

Super Belle Meeting 11

Output Voltage of PP (diode mode)

2008

2008

2009

2009

Super Belle Meeting 12

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).

Super Belle Meeting 13

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

Super Belle Meeting 14

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.

Super Belle Meeting 15

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.

Super Belle Meeting 16

Backup Slides

Setup picturesMonitoring pictures

Super Belle Meeting 17

Setup: Outside View

APD

P.P.

Box Size

Setup

Super Belle Meeting 18

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.

Super Belle Meeting 19

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.

Super Belle Meeting 20

Output Monitoring

VoltageTemperature