DAQ-expert materials
Test of Si detector packages:
A-6 A : STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A6_detAcorrect.pdf
A-6 B : STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A6_detBcorrect.pdf
A-6 C : STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A6_detCcorrect.pdf
A-6 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A6_detDcorrect.pdf
A-6 Trigger system: STAR/system/files/userfiles/2729/file/Assembly_test/A_6_cosmic.pdf
A-1 A: STAR/system/files/userfiles/2729/file/Assembly_test/AssemblyA1_detA(1).pdf
A-1 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A1_detB(1).pdf
A-1 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembl_A1_detC.pdf
A-1 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembl_A1_detD.pdf
Trigger system for A-1 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/PMT_A1.pdf
A-4 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A_4_detA.pdf
A-4 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A_4_detB.pdf
A-4 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A4_detC.pdf
A-4 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A4_detD.pdf
Trigger system for A-4 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/PMT_A_4.pdf
B-1 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B1_detA.pdf
B-1 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_1_detB.pdf
B-1 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_1_detC(1).pdf
B-1 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_1_detD.pdf
Trigger system for B-1 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/B_1_cosmic.pdf
B-2 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B2_detA.pdf
B-2 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_2_B.pdf
B-2 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_2_C.pdf
B-2 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B_2_D.pdf
Trigger system for B-2 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/PMTB2.pdf
B-4 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B4_detA.pdf
B-4 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B4_detB.pdf
B-4 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B4_C.pdf
B-4 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_B4_detD.pdf
Trigger system for B-4 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/B_4_cosmic.pdf
B(A)-5 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_BA5_detA.pdf
B(A)-5 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly%20_BA5_detB.pdf
B(A)-5 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_BA5_detC.pdf
B(A)-5 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_BA5_detD.pdf
Trigger system for B(A)-5 assembly: STAR/system/files/userfiles/2729/file/Assembly_test/PMT_BA5.pdf
A-3 A: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A3_detA.pdf
A-3 B: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A3_detB.pdf
A-3 C: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A_3_detC.pdf
A-3 D: STAR/system/files/userfiles/2729/file/Assembly_test/Assembly_A3_detD.pdf
A-3 Trigger system: STAR/system/files/userfiles/2729/file/Assembly_test/A_3_cosmic.pdf
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Test of trigger counters:
Setup
Test of the trigger counters was performed using (see first photo):
- high voltage power supply,
- Tektronix MSO 3034 Mixed Signal Oscilloscope,
- beta radiation source 90Sr.
Trigger counters were left in the storage boxes to avoid possible damages. Both PMTs in the counter were supplied with the same voltage, which was changed in a range 800-1200 V. Beta source was always sitting on the surface of the scintillator, pointing to it (like on the second photo). Measurements were done with the source in a few different points on the surface of the scintillator, in order to determine position dependencies. As shown in the third photograph, storage boxes with trigger counters were additionally placed inside the folder with zipper to fully avoid influence of the external light.
In order to enable offline analysis, some number of waveforms from both channels (PMTs) was stored on a USB flash memory in *.isf format (internal save format of the scope). Then, isf files were converted into ROOT histograms and processed (contact me to get the converting program).
Dark noise measurement
This measurement was done without use of the 90Sr source. Signals were triggered with very low threshold value (order of mV, depends on supplying voltage). The lack of signal in the PMT other than the triggering one (like on the figure below; red = channel 1, blue = channel 2) was a confirmation for non-cosmic-ray origin of the pulse.
For such events the dark-noise peak amplitudes were histogramed. Links to plots of these histograms are contained below.
A-3 A-6 B(A)-5 B-1
As an output the dark noise levels as a function of the supplying voltage were prepared for each channel separately: DARK NOISE vs. VOLTAGE.
Detailed tests with 90Sr source - part 1
The main part of the test was done with the beta source placed in three points on the scintillator, as shown in red on the right-hand side sketch. For each position of the source and each PMT voltage, about 150 triggers were collected. The triggering threshold was set to ~2sigma above the noise level, based on the dark noise measurement (see above). Only one of the channels was set to trigger. An exemplary output from oscilloscope is presented in the left-hand side figure (below), together with description of quantities whose distributions are available in the table below.
| quantity \ counter | A-3 | A-6 | B(A)-5 | B-1 |
|---|---|---|---|---|
| Signal amplitudes (correlation between channels and 1-D amplitude distributions) |
||||
| Signal integrals (correlation between channels and 1-D integral distributions) |
||||
| Time difference between moments of reaching the threshold by signals in two channels |
||||
| Rise time (correlation between channels and 1-D rise time distributions) |
||||
| Fall time (correlation between channels and 1-D fall time distributions) |
Explanation of quantities from the table:
Signal amplitude is nothing but the maximum absolute value of the pulse (at peak).
Signal integral is simply an integral of the pulse over time.
Time difference (\delta t, difference in time of discrimination) is the time interval between the moment of reaching the threshold level by the pulses in two channels (see the left figure above).
Rise time is defined as the time interval for the pulse to reach 10% and 90% of its peak value (see the left figure above).
One should note, that the time difference contains a component which depends e.g. on the lenght of wires connecting PMTs with the oscilloscope, so only the relative time difference ("difference between time differences") should be studied.
Detailed tests with 90Sr source - part 2
The second part of the tests was also done with the use of beta source, this time however a more detailed position dependence (11 different points) of the pulse properties was checked. For each position of the source and supplying voltage only one waveform (for each channel) was saved (instead of ~150 as in part 1), however, a waveform itself was an average of 512 triggered pulses (the same trigger thresholds were set for corresponding voltages as in part 1). Examples of the average pulses from two channels are presented in figure below. Results of the 2nd part of tests are contained in the table below.
| quantity \ counter | A-3 | A-6 | B(A)-5 | B-1 |
|---|---|---|---|---|
Average-signal amplitudes |
||||
Time difference (for average signals) |
The black contour in the plots in the table above marks the area of the scintillator (8 cm x 5 cm). Colours of markers correspond to the value of presented quantity (see description of z-axis).
- Printer-friendly version
- Login or register to post comments