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Comparison of MIRAC-4 array with Cornell test array, both warm ver 3Bill Hoffmann November 10, 2009

Test configuration Array: MIRAC-4 array or Cornell test arrayController: NIC electronics box with new preamp, backplane, FPGA, bias, and clocksSoftware: Linux version Cornell server and gui’s plus UA filter and other gui’sPower supply: Original MIRAC-4 power supplyPower cable: Original MIRAC-4 long

Cable from backplane to cryostat: Original MIRAC-4 cable or Cornell test cableCable bulkhead to fanout board: Second edition MIRAC-4 cable or Cornell test cable

Bulkhead connectors: Original MIRAC-4 cryostat hermetic bulkhead connectors or Cornell test connectorsFanout board: MIRAC-4 or Cornell test board

Ground interconnects: Chosen by Paul Arbo for best operation

Results:

The Cornell test assembly gives clean images without digital pickup (flash bars). The Cornell array in the MIRAC fanout board with the Cornell cryo signal cable gives the same results. The MIRAC array in the MIRAC fanout board with the Cornell cryo signal cable has slightly more noise but no flash bars. Both the MIRAC and Cornell arrays in the MIRAC fanout board with the MIRAC cryo signal cable have flash bars.

Pickup from the motor power supply is large with the MIRAC system. It is small with the Cornell warm test assembly and the same with the MIRAC or Cornell array in the MIRAC fanout board with the Cornell cryo signal cable.

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On the following page the upper two images are for the MIRAC fanout board and MIRAC cryo signal cable. The MIRAC array is on the left and the Cornell array on the right. Both show “flash bars”. Three or so show on each image with the warm arrays. With the MIRAC system cold, these bars frequently appear all over the images.

The lower images are for the Cornell cryo signal cable. The two images on the left use the MIRAC fanout board. The leftmost image is the MIRAC array and the center image the Cornell array. The image on the right is with the Cornell warm test assembly including the the Cornell fanout board. The flash bars are absent from all three images.

The defects along the left and right side of the MIRAC images are debonding of the indium pads.

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MIRAC array; MIRAC fanout Cornell array; MIRAC fanout

MIRAC array; MIRAC fanout

MIRAC cryo signal cable

Cornell cryo signal cable

Cornell array; MIRAC fanout Cornell array; Cornell fanout

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Shields Fanout Screen Flux Stdev Screen Flux StdevConfig Warm Cryo Cut Other Board Array Loc Shot DET DU DU Shot DET DU DU

1 MIRAC MIRAC - MIRAC MIRAC in m14-04 1.456 8157 3.7 m14.03 1.456 8157 72 Cornell MIRAC - MIRAC MIRAC in m14-20 1.456 8000 3.7 m14-25 1.458 7900 6.53 Cornell MIRAC sig MIRAC MIRAC in m29-08 1.458 8650 3.8 m29.12 1.458 8360 6.54 Cornell MIRAC bias MIRAC MIRAC in m29-15 1.458 8442 3.8 m29-18 1.458 8527 6.55 Cornell MIRAC clock MIRAC MIRAC in m29-21 1.458 8550 3.8 m29-24 1.458 8439 6.26 Cornell MIRAC demount fanout MIRAC MIRAC in m29-27 1.456 8510 4 m29-30 1.456 8420 4.87 Cornell MIRAC MIRAC MIRAC in m29-45 1.457 8095 3.5 m29.48 1.457 8089 58 Cornell Cornell MIRAC MIRAC in m29-33 1.457 8510 3.6 m29-36 1.457 8379 3.79 Cornell Cornell remove strain MIRAC MIRAC in m29-39 1.457 8342 3.7 m29.42 1.457 8350 3.5

10 Cornell MIRAC MIRAC Cornell in m29-51 (2.002) (4795) 3.5 m29.54 (2.005) (4452) 4.711 Cornell Cornell MIRAC Cornell in m29-70 1.976 8360 3 m29-71 1.976 8350 3.3

Shields Fanout Screen Flux Stdev Screen Flux StdevConfig Warm Cryo Cut Other Board Array Loc Shot DET DU DU Shot DET DU DU

1 Cornell Cornell - Cornell Cornell in m29-70 1.976 8360 3 m29-71 1.976 8350 3.311 Cornell Cornell - Cornell Cornell in m29-70 1.976 8360 3 m29-71 1.976 8350 3.3

Motors onCables

Motors off

CablesMotors off Motors on

Clock 254 Hz, Frame 3.93 msec, Chop 4.89 Hz, Wait 98.3 msec, Time 0.21 sec, Stack 1, Source -4.52 V

The top table is with the MIRAC fanout board and various combinations of warm and cryogenic cables, fanout board mounting hardware, array, and motor power supply off and on. The lower table is for the Cornell warm test cable and array test assembly.

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Configuration

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mirac motors off mirac motors on cornell motors off cornell motors on

Isolate array from ground

Cornell cryo sig cable

MIRAC cryo sig cable

The red lines for the Cornell warm assembly and fanout board. The dashed line is for the motor power on. This is our baseline for no “flash bars” and minimum motor power pickup. The blue lines are for the MIRAC fanout board. Significant reduction in motor power pickup occurs with isolating the array cold finger from ground and using the Cornell cryo signal cable. These have little effect on the motor-off standard deviation. But with the MIRAC cryo signal cable both the MIRAC and Cornell arrays show flash bars. These are eliminated with the Cornell cryo signal cable. The filled orange triangles are the Cornell array in the MIRAC fanout board. The Cornell array has slightly lower noise in either the Cornell or MIRAC fanout board than the MIRAC array.