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 SPIRO S/N Confirm that the SPD FEM is reading the correct S/N 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

Test Box Setup You have to do all the processes very carefully. 1. Remove the top cover and bottom acrylic plate. It is helpful to place across the test box to support the stave just above it until you’re ready to lower the stave into the box. This is also useful during disassembly. 2. Attach tubes for NOVEC. - Silicon grease is used to put on and off them smoothly. It is applied to the inside of the tubes. 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.

Applying Silicon Grease

Ladder Connector Bias Voltage input Bias may be connected to either Bus Data Connectors 3.5 V Gnd

Bus Connections Bus data connectors Ground Ladder 3.5 V Bias Bus/ladder power connections Ground and Ladder wires may be connected in any position within their correct connector

Connecting Bus and ladder Power connections: Ladder and Ground are soldered onto the ladder side, so they must be plugged into the bus connection. Bias should remain connected to the bus, and plugged in to the ladder Data connectors are attached after power. They should be clean of dust before connection. Use canned/compressed air, and make sure that you are blocking or preventing dust from blowing onto the ladder itself. Line up the bus and ladder connectors and when the connection is aligned, press the connectors into place. Be Careful with this connection.

Interlock system Before powering the system, you must pass the interlock system checks. Interlock system checks humidity inside test bench, the 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 condensation on ladders. 2. After the humidity gets low enough (0% relative humidity), start the pump and refrigeration, and open the valves (including the valve on the interlock).

Interlock system Valve control: Open Close Interlock power Relative Humidity: measured threshhold Temperature reading (here, of the NOVEC, as no temp. sensor is on the staff) System Checks: green light indicates check passed, red light indicates check failed Valve, Output, Humidity, Temp, Flow Humidity sensor reading

Low voltage After all interlocks are passed, 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. (approximately at the rate of.1V/sec) - Before you turn on the power supply, you have to check the output voltage set to its lowest value. - As you increase the voltage the current through the ladder goes through a rapid rise around 2 V. If it rises quickly to 5 A, pause to allow the system to equilibrate and then continue without allowing the current to pass 5 A. You’ll notice after the system is powered up, the current will drift down over time. 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, consider that there may be some problem. - 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.

Low Voltage Setup Right Half-LadderLeft Half-Ladder

Disassembly notes In general, simply proceed through the assembly procedures in reverse Gradually decrease the Ladder/Bias voltage, power down electronics. Turn off cooling, allow the stave to come closer to room temperature (to prevent condensation when you open the test box) Open test box, lift out stave. Carefully disconnect the NOVEC tubes: Use a ~2mm or 5/64” hex (Allen) wrench to support the Stave (see following picture) Twisting back and forth, slowly pull off the NOVEC tube. Using a plastic sheathed eyeglass screwdriver (as pictured) carefully pry the bus data connection off of the ladder. Disconnect the Ladder and Ground from the Bus, and the Bias from the Ladder. Tilt ladder to drain remaining NOVEC. Return stave to casing.

Disassembly Tools Minor divisions are ~ 1mm

Novec Tube Removal Note the position of the wrench supporting the stave

Removing Data Connector

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. - The above values are stored for each SPIRO board in a spreadsheet. The FEM should read off the proper S/N automatically, but you should confirm that the S/N matches each time you power up the FEM.

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.

Additional Pictures

Chiller

Supporting the Ladder We used this book to support ladders coming out of and going into the test box.

Spiro connection on Bus

Bus connection on SPIRO Test Boards

SPIRO board connected

Left Ladder connection