[Aidan, Jordan, Radhika]
Radhika and Jordan identified some particulates (hair and flecks of foil) on the O-ring on the IR labs dewer. Additionally, we saw a scratch in the O-ring groove and a nick on the metal of the base of the dewer where it meets the O-ring. All were in the leaky vicinity previously identified by the He testing.
We set up a cradle to hold the dewer while we are working on it. Still needs vertical supports.
R & J replaced the O-ring with a new one with Crytox applied.
Purchased from Lesker, for venting of IR Labs Cryostat:
- P/N C35103000 (KF10 Valve for up-to-air)
- P/N QF25XQF10 (KF25-KF10 Reducer)
- P/N QF25-100-T (KF25 Tee)
(to be connected in between the Chamber Tee and the Gate Valve)
Should be in next week!
[JC, Chub, Radhika]
Chub and I ordered a few parts from McMaster in order build a handrail-like stopper to keep the dewar from falling over. We also cut off the excess 8020 which was leaning over the table to fit. To hold down the support for the Dewar, Radhika and I decided to use C-clamps from the EE shop.
Stephen and I added a new valve to Dewar's vacuum system. This valve allows the flow of atmospheric pressure into the system. We added 3 components to the system which were the valve, an adapter, and a T-intersection. After added these components, we continued to pump down only the highlighted yellow and green area with Dewar being closed off. The system pumped down to .1 mTorr until we decided to close off the pump. Once we close the pump off, we noticed the pressure began to rise. We took apart the system again and looked over the O-rings. We came across one ring with a sticky and clear material surround the rim and another ring with a fiber on it. We proceeded to clean and reassemble the system, but ran into this same issue. We tried to find where this leak was by squirting isopropyl around each ring and posibbly so a slower rise in pressure, but had no luck.
Afterwards, I checked both T-intersections individually and came across the same rise in pressure after closing off the valve for both tests. We suspect this may have been normal beforehand?
We continued by putting it all back together and taking data of the pumpdown.