From ryantu at stanford.edu Tue Aug 22 00:06:06 2006 From: ryantu at stanford.edu (Ryan Tu) Date: Tue, 22 Aug 2006 00:06:06 -0700 Subject: Cryostation reservations Message-ID: Dear All, I would like to open a discussion to increase the availability of the cryostation. Currently users are blocking out up to three days at a time, 24 hours per day. I am guessing that a large portion of that time is not being used for actual probing, however, I would like to get feedback from users as to how much of the reserved time is actually used. Since the leak is now fixed, a pump down to appropriate levels before cooling should take less than two hours and then the cool down itself should take no more than an hour, for a total of three hours per sample load. As a start for the discussion how about limiting the reservation to a 8-10 hour block for a 24 hour period. This would give a user 5-7 hours of probing at low temperatures. If more time is needed, then the user can make additional reservations in subsequent days. Please reply for any comments or other suggestions. If users are finding that they need more than 5-7 hours to probe, that would be useful as well. I have just observed that in many instances, large blocks of reserved times are unused and could be used by other users. Ryan From aokyay at stanford.edu Tue Aug 22 00:31:12 2006 From: aokyay at stanford.edu (Ali K. Okyay) Date: Tue, 22 Aug 2006 00:31:12 -0700 Subject: Cryostation reservations In-Reply-To: Message-ID: <001701c6c5bc$f1db1c30$6500a8c0@Reyyan> Hi all, I tend to agree with Ryan that long block reservations do limit the availability of the station for other users. However, one also needs to consider the amount of time it takes to bring the sample up to room temperature after probing is finished. This seems to take as much time if not more than cooling down. We are looking at a 4-5 hour overhead time per sample. The rest of the time users do measurements, and more often than not at more than a single temperature point, simply increasing the probing time by a few factors. Given all the overheads, the current 2-day-max rule seems ok to me, but I guess we could try a 24-hour-max limit as well. Regards, Ali -----Original Message----- From: Ryan Tu [mailto:ryantu at stanford.edu] Sent: Tuesday, August 22, 2006 12:06 AM To: cryostation at snf.stanford.edu Subject: Cryostation reservations Dear All, I would like to open a discussion to increase the availability of the cryostation. Currently users are blocking out up to three days at a time, 24 hours per day. I am guessing that a large portion of that time is not being used for actual probing, however, I would like to get feedback from users as to how much of the reserved time is actually used. Since the leak is now fixed, a pump down to appropriate levels before cooling should take less than two hours and then the cool down itself should take no more than an hour, for a total of three hours per sample load. As a start for the discussion how about limiting the reservation to a 8-10 hour block for a 24 hour period. This would give a user 5-7 hours of probing at low temperatures. If more time is needed, then the user can make additional reservations in subsequent days. Please reply for any comments or other suggestions. If users are finding that they need more than 5-7 hours to probe, that would be useful as well. I have just observed that in many instances, large blocks of reserved times are unused and could be used by other users. Ryan From ahazeghi at stanford.edu Tue Aug 22 14:00:20 2006 From: ahazeghi at stanford.edu (Arash Hazeghi) Date: Tue, 22 Aug 2006 14:00:20 -0700 Subject: Do not leave the system unattended Message-ID: <5de16f72e28fb4654b704afe9fb0ee4d@stanford.edu> Hello, I saw today that the system was left at 77K for at least several hours with no one using it, I want to emphasize that users are not allowed to cool down overnight or leave the system unattended when liquid N2 is being used. There was frost all the way from the bayonet to the refrigerator and liquid was overflowing from the exhaust port. I closed the foot valve to prevent further spill. Please adjust your timing so that you can proceed with measurements as soon as the system is ready. If you need to do measurements two days in a row and you want to keep the system cool overnight make sure you close the back pressure line and open the foot valve by half a turn only. There should not be any liquid spill from the system. If the system is being found idle at 77K for more than two hours, system will be warmed up, sample removed and the current reservation cancelled. Thank you, Arash ------------------------------------------------------------------------ -- Arash Hazeghi PhD Candidate Stanford Center for Integrated Systems, 420 Via Palou Mall, CIS-X 300 tel: 650-725-0418 mobile: 650-353-1866 http://www.stanford.edu/group/nanoelectronics/index.htm From ryantu at stanford.edu Wed Aug 23 16:56:32 2006 From: ryantu at stanford.edu (Ryan Tu) Date: Wed, 23 Aug 2006 16:56:32 -0700 Subject: Broken chuck Message-ID: Dear Users, I just noticed that the chuck that is currently in the system is grounded and that the floating chuck is broken once again. In the future, can the user who breaks the connection send out an email or give some sort of notice? That way we can fix the problem immediately. Ryan From ahazeghi at stanford.edu Fri Aug 25 16:22:26 2006 From: ahazeghi at stanford.edu (Arash Hazeghi) Date: Fri, 25 Aug 2006 16:22:26 -0700 Subject: Please remove the transfer line Message-ID: <001301c6c89d$538e6760$6601a8c0@AHWK32> Transfer line is not allowed in the system when system is disabled, if you are doing measurements and need the transfer line connected keep the system enabled on Coral. Thanks, Arash -------------- next part -------------- An HTML attachment was scrubbed... URL: From aokyay at stanford.edu Wed Aug 30 10:28:40 2006 From: aokyay at stanford.edu (Ali K. Okyay) Date: Wed, 30 Aug 2006 10:28:40 -0700 Subject: res removed today Message-ID: <000501c6cc59$bc072ba0$e38d0c80@Reyyan> Sorry for the late notice. -------------- next part -------------- An HTML attachment was scrubbed... URL: