Measurement

We have 14 wafers. Each wafer has a diameter of 5 cm, and a thickness of 2 mm. The measurement usually takes one or two weeks.

Processed data

Each data file lasts three hours. The processed background data for different types of wafers can be found under these directories, (T: standard, CF: low light yield, fast time response , HL: high light yield)

cd /data/Reconstructed_GAGG_wafer_T1/

cd /data/Reconstructed_GAGG_wafer_T2/

cd /data/Reconstructed_GAGG_wafer_T3/

cd /data/Reconstructed_GAGG_wafer_T4/

cd /data/Reconstructed_GAGG_wafer_T5/

cd /data/Reconstructed_GAGG_wafer_T6/

cd /data/Reconstructed_GAGG_wafer_T7/

cd /data/Reconstructed_GAGG_wafer_T8/

…T wafers to be continued…

cd /data/Reconstructed_GAGG_wafer_CF1/

cd /data/Reconstructed_GAGG_wafer_CF2/

cd /data/Reconstructed_GAGG_wafer_HL1/

cd /data/Reconstructed_GAGG_wafer_HL2/

The processed calibration data for different types of wafers can be found under this directory,

cd /data/Reconstructed_GAGG_wafer_calib

PSD

Gamma events with an integral of above 20000 and less than 30000 are selected to build the average spectrum. The waveform's amplitude should be larger than 600.

To have a quick look at the PSD power, type the following command in the terminal,

global→Draw(“chi2_poweraverage.relativeamplitude:integral.integral»(1000,0,80000, 100, 0, 2)”,“”,“colz”)

In the chi2 module, the relativeamplitude shall be used, instead of the amplitude.

The figure below shows an example of wafer “T1” with 5 days data-taking

Things could be done

* Decay time: fit the average spectrum with two separate step functions times exponential functions, one representing the slow component of the decay time, and the other for the fast component. The time response should change with wafers

* Count rate of 152Gd, should be similar for different wafers, and the 147Sm may differ depending on the contamination

* Alpha contamination