Stave 4028 Thermal tests Electrical tests

4028: THERMAL TESTS We have studied the effect of the liquid speed on the modules heating. Test 1: all 13 modules are powered and configured (SURF and ROD): about 50 W Test 2: measure of (  T/power) for each module powered one at a time (only half stave - SURF). Is it possible to set a threshold for the variable  T/power as we have done until now indipendently of the cooling variables?

General conditions We are using 2 indendent circuits to cool down the stave and the box T_CoolingStave= -20C T_CoolingBox = -6C T_InsideBox = 3C Speed of the cooling inside the Al pipe set to 1 (slow), 4, 8 (fast).

Test 1: all modules powered Test 2: modules powered one at at time Example of monitoring on 4 modules…

Example of temperature monitoring on 4 central modules… Test 1: all modules powered Test 2: modules powered one at at time Speed 4 Speed 1 Speed 8 Speed 4 Speed 1 Speed 8

Results of Test 1 (all modules on) Cooling direction When speed is low 1 -4, there is a significant increase of temperature along the stave (Tmax –Tmin 10C!) A better uniformity is achieved incresing the cooling speed (Tmax –Tmin 4C)

How cooling speed change the  T/power?

4028 Electrical tests LOAD/STAVE tests are performed using 2 SURF boards. Comments: In the STAVE macro with respect to the list, it is not included DVDD scan as DVDD is not controlled by TDAQ anymore but by ambush. The scan can be done modyfing the ambush script but… Threshold scan with HV off with SURF is sometimes very different from scan HV off with MAC (due to my SURF or my script??)….see slides 10-11

Example of T monitoring during STAVE test: MODULES 7-13 TEMPERATURE 7 hours for half stave (source excluded) Cooling flow Test Test Test Module Test direction

HV off with SURF or with MAC Noise ~400e!

Then the analysis finds Unconnected bad pixels with this low rows peculiar pattern!

Electrical tests analysis STAVE\FLEX Comparison done using the “official” STAVE cuts without cut on HVoff data (as there is the source scan). LOAD\BURN comparison done with the official LOAD cuts (but some fake problems as HVoff is unusually good) The two modules with pre-existing large defects increase the number of bad pixels during loading and cycles. In 2 modules new small defects (about 20 pixels) are visible between chip 4 and 5 after loading.

Bad pixels New Defect between 4 and 5 Increasing in pre-existing defects

M2a and M4a There after loading: is there anything that can damage that point?

M5a Increasing both in loading and cycling

M6A Increasing mainly in loading