2016/01/28 (Thursday)

Previous Day

	Setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50
	Taking Y-Be photoneutron data overnight. Last flash at 07:01
	Last night's data failed, because DIB3's phonon trace lengths were set wrong. Need to be more careful after modifying trace lengths with pulse viewer.
	Also looking at data it appears that the raw event rate was much too high. We will probably need more lead shielding with the current setup.
0830	Removed strong Y source from Y-Be source holder.
0840	Tower/MC(H35)/MC sensor/Cold Plate = 31.4/27.2/41/161 mK, Still = 1.30 K / 0.12 mbar, G1/G2 = 190/185 mbar, 1K Pot = 1.73 K / 19 mbar, Main bath = 71.6%
0845	Fill LN2 cold trap Dewar.
0855	Check phonon channels, all look OK
1000	Anthony has modified the way the DAQ queries the DCRCs for triggers. It may change our max read rate. The following series will serve as a test of this.
1013	Start 1 30min background(bg) series at -4/+4V with FG=5/2/5, OG=3, with 1000 initial randoms, 1000 ending randoms, 30s flash and 25 minute cooldown before series. Trigger on DIB1 phA with threshold of 20ADC bins.
1155	Checking raw background rate, now that we have the north-side lead removed. Count 50 events in 0.5 s for 100 Hz.
1205	Put Y-Be source in place in yesterday's setup: two layers of lead brick (4“), stacked two high. Count ~31 events in 0.05 s, 620 Hz. (86% pileup)
1210	Using taller bricks as bottom layer, so that shielding reaches higher. Still 4” thick. Count ~31 events in 0.05 s again. Same as above.
1235	Rearranged so that lead is 5“ thick. Count ~33 events in 0.05 s. Still high.
1235	Rearranged so that lead is 6” thick. Count ~26 events in 0.05 s, 520 Hz. Still high.
1253	We cannot move the source back any further from the detector without removing the aluminum frame of the north-side of the shield. Then we'll have to extend the platform that's holding the source-holder somehow.
1420	Several phonon channels railed for some reason. Most came back after a relock. Had to change ADCoffset of DIB1pD from -0.11 to 0.15.
1445	Rearranged Y-Be source holder so that there is 8“ lead between source and fridge. Count 55 events in 0.25 s = 220 Hz (52% pileup).

Y-Be source setup, north shield wall removed, with 8” of lead
In this setup, Y source is nearly level with detector
Y source is 11“ from inner side of inner poly sheet

1526	Two “bugs” were added to CDMSDAQ Jira page. The first was to report sporadic crashing of SQUID tuning GUI in MidasTools, and the second was to request that QET Bias slider range in DCRC UI settigns be increased from (-27,27) to (-1000,1000). commit version:76bee74ceb347f32c25102c5dbae37a5399eca1c
1525	Place Ba source inside mu-metal shield near top
1526	Start 1 30min Ba series at +4/-4V with FG=5/2/5, OG=3, with 1000 initial randoms, 1000 ending randoms, 30s flash and 25 minute cooldown before series. Trigger on DIB1 phA with threshold of 20ADC bins.
1640	Fill LN2 cold trap full.
1700	Start 15 hours of 30min Y-Be series at -4/+4V with FG=5/2/5, OG=3, with 1000 initial randoms, 1000 ending randoms, 30s flash and 25 minute cooldown before series. Trigger on DIB1 phA with threshold of 20ADC bins.

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