Ladder QA manual

Check items 1 Interlock - Temperature of NOVEC. ✓ Check the difference from the value where the QA in RIKEN was performed is less than 5 ℃. - Humidity inside test box. ✓ Check the difference from the value where the QA in RIKEN was performed is less than 5% Power supply - Voltage and current of the power supply for SPIRO and LADDER at the operational voltage. ✓ SPIRO: Check the difference of the current from the value of the same SPIRO is less than 0.1A. ✓ LADDER: Check the difference of the current from the value where the QA in RIKEN was performed is less than 0.1A. - Bias voltage and leakage current at each 5V. ✓ Check the difference of the leakage current from the value where the QA in RIKEN was performed is less than 0.3μA.

Check items 2 DAC value - Reference voltage. (DAC_REF_VDD, DAC_MID, and GTL_REF) ✓ Check the difference from the value of the same SPIRO is less than 2. - Threshold value for each chip. ✓ Check the difference from the value where the QA in RIKEN was performed is less than Mask pixel. ✓ Check there are difference from the result of the QA in RIKEN. Hit map using β ray source. ✓ Check the difference of dead area.

Procedure of QA

Set a ladder You have to do all the processes very carefully. 1. Remove the top cover and bottom acrylic plate. 2. Put tubes for NOVEC. - Silicon grease is used to put on and off them smoothly. 3. Set extenders and cables for power supplies for ALICE chips and bias voltage and for GND. - You have to be care about the connection at connector for data or control signals since a wrong connection cause some wrong responses of ladders.

Interlock system First of all, you have to unlock the interlock system. Interlock system check humidity inside test bench, flow rate and temperature of NOVEC, and whether the valve is open or not. 1. First, you have to flow N2 gas to decrease the humidity. This has to be done before flowing NOVEC to prevent dew condensation on ladders. 2. After the humidity get enough low, you start to operate the chiller and open the valve.

Low voltage After all interlocks are unlocked, you can start to supply voltages to SPIRO board (SPIRO), chips on ladder (LADDER), and silicon (BIAS). First you have to supply to SPIRO, next to LADDER, and the last to BIAS. The voltage supplied to SPIRO is 5.0V. When you supply to LADDER, you have to turn up the voltage slowly from 0V to 3.5V. - Before you turn on the power supply, you have to check the output voltage set to 0. - If the current is over 5.5A (this is a empirical value.), you have to doubt there are some trouble. When you supply to BIAS, you have to turn up the voltage slowly from 0V to 50V. - If the current is anomalously large, in comparison with the value at the test in RIKEN, you have to doubt there are some trouble. - There are some modules which can not operate with the bias voltage of 50V due to large leakage current or continuous increase of leakage current. You have to check proper operational bias voltage before supplying the voltage.

Data acquisition Data are send from SPIRO board to FEM via fiber cable and read from FEM through USB cable. Ops system is used for data acquisition. User name and password of DAQ PC is - User name : pixel - Password : pixel*3186

Detail of DAQ operation

1. Select USB mode. 2. Check the HS channels which you are using. 3. Push “RST” button. 4. Push “GO” button

Set proper values for taking data at some registers. - ADDR=0x4, 0x14, 0x24 : select the chips where FastOR signals (self trigger signal) are accepted. ✓ If you use readout channel of 0-3 and accept all FastOR signal from them, you have to set 0x4, 0x14=0xff and 0x24=0x0. - ADDR=0x60, 0x61 : set the maximum trigger rate ✓ 0x60=0x20 and 0x61=0x0 means the maximum rate is 20Hz - ADDR=0x62, 0x63 : set trigger mode. (external trigger mode or self trigger mode) ✓ External trigger mode : 0x62=0x0 and 0x63=0x0 ✓ Self trigger mode : 0x62=0x1 and 0x63=0x1 (Ladder QA is carried out in self trigger mode.)

Set DAC values (DAC_VDD, DAC_MID, GLT_REF) of analog pilot. - Set the HS channel which you intend to set DAC values via “HS Channel Number” panel and set proper DAC values via “Set Analog Pilot DACS” panel. - The DAC values are optimized so that the reference voltage be proper values. ✓ The proper reference voltages are DAC_REF_VDD=1.8V, DAC_REF_MID=0.955V, GTL_REF=0.8V ✓ The reference voltage can be measured at tester adapters. - They are for SPIRO board. The DAC values for each SPIRO are stored in a file and you can obtain from the file. For the initial setup, the serial number of the SPIRO are identified and the DAC values are set automatically.

Set trigger latency Set threshold values for each chip Set mask and test bit

Set threshold values Threshold values have to be optimized. - You can this optimization by checking FastOR signals which are triggered by noise. FastOR signal can be checked via tester adapters. - Setting larger number means setting lower threshold. - You can find the pixels which have to be masked. The pixels whose threshold is higher than the other pixel at the same chip have to be masked.

Set mask and test bit 1. Select the chip which has the pixel you want to mask (send test pulse). 2. Select the pixel position. 3. Set mask (test) bit. - ALL : Set all the pixel in the chip. - COL : Set all the pixel in the column. - BIT : Set the pixel in the column and the row. 4. You can save and read the bit information

Two dimensional hit map for each chip is shown Take data with external or self trigger Take data with force trigger. Convert data to EXEL file.

DAQ rate is shown Start data taking with external of self trigger. Stop data taking. - Write file: Write data to a file - Graph Display Display hit map. If you display hit map, DAQ rate decrease. It is better not to display when you intend to store data for analysis. Clear hit maps. Take data with force trigger by pushing this button.