2017/08/28 (Monday)

Status	IVC open, 4K disassembly finished. Both LN2 traps warm and pumped out. Mixture in dump (LHe cold trap isolated at around 20 K). 1K Pot needle valve open. Cryostat vacuum jacket pumped out.
1115	Finish wirebonding S1502 (see Aug 18). On channel C it was difficult to get bonds to stick to detector pads, used power setting of 495. Resistance check: no leaks to chassis, channel-to-channel all a few hundred Ω. Also measured from DIB pin to channel on detector directly - a few Ω for the channel in question. There seemed to be a short between Channels D (ring next to center channel) and E (center channel) - only a few Ωs between them - we inspected and found a place where there seemed to be a thin connection across the channel separating D and E, so we tried surgery by scraping that spot with a hypodermic needle. This seemed to fix it - the channels now show a few 100 Ω between them.

Status

IVC open, 4K disassembly finished. Both LN2 traps warm and pumped out. Mixture in dump (LHe cold trap isolated at around 20 K). 1K Pot needle valve open. Cryostat vacuum jacket pumped out.

1115

Finish wirebonding S1502 (see Aug 18). On channel C it was difficult to get bonds to stick to detector pads, used power setting of 495. Resistance check: no leaks to chassis, channel-to-channel all a few hundred Ω. Also measured from DIB pin to channel on detector directly - a few Ω for the channel in question. There seemed to be a short between Channels D (ring next to center channel) and E (center channel) - only a few Ωs between them - we inspected and found a place where there seemed to be a thin connection across the channel separating D and E, so we tried surgery by scraping that spot with a hypodermic needle. This seemed to fix it - the channels now show a few 100 Ω between them.

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