__________ Report on October 2010 SHARP setup: ____ Overview: ____ During Oct 26-28 I removed the 450 micron HWP and installed the 350 micron HWP. I verified that the optical alignment was within spec. Then I tested the system via "fake observing". Basically, everything seems to be working well, though there is some odd behavior in the IRC-to-EDAS link which has me slightly concerned. But hopefully it will be OK. The odd behavior is described in the last section below. I did not test the chopper. ____ HWP swap: ____ I did not implement the new wavy washer system that we implemented for the first time in July 2010 using the 450 micron plate. Instead, I used the older cork system. This is due to a design flaw in the HWP pocket in the brass piece that the HWP slides into. It should have a diameter of around 4.005" but it is closer to 4.000". This can be changed in future though it is a bit of work. The cork has worked well for the 350 micron HWP in the past so it should be OK. I aligned the HWP according to the usual marks. ____ Optical alignment: ____ subarray misalignment was measured to be 0.2 pixel, and parallelism was measured to be 0.1 pixel. This is within spec; I decided not to make any adjustments. ____ System tests: ____ "Fake observing" was done, which tests whether all computers are talking. Via a "SHARP Single File" I verified that the telescope was nodding and the HWP was advancing and the HWP angles were being stored to the data file (i.e. I ran readsharc on the fake data file and got the usual "steps"). As noted above there was some odd behavior of the EDAS-to-IRC link. This is described in the last section of this report. ____ Grid Test: ____ The quick Vnull grid test was done and Vnull was found to be around 96, indicating that the HWP flag is around 90, as always for this 350 HWP. A more careful analysis will be done later. ____ Odd Behavior in the EDAS-to-IRC link: ____ Two differences were noted in comparison with recent behavior. (1) One time the system did not start properly. On Tuesday the system started up fine, but on Wednesday, the first time I tried to move the half-wave plate via the "SHARC Controls" window, I got a dialog box that said: "Polarimeter not Currently Available". I went to the EDAS web page and verified that hwp.exe was running. Then I shut down the client and server, power cycled the EDAS, and started up the server and client again. It worked fine. I repeated this EDAS-server-client shutdown/startup sequence two more times as a test, and it worked both times. On Thursday the system started up fine. So we are 5 for 6 on successful EDAS-IRC startups in October 2010. I can't think of anything I did to cause the one failure. (2) The second difference is that when the IRC server starts up, it now prints the following line 30 times in a row: InitializePolarimeter.run Both Darren and I agree that it never used to do this so many times. My memory is it used to print this message about 5-10 times in a row. This is all a bit worrisome but I think probably it will be OK. I plan to alert everyone who has expertise that is relevant to the EDAS-IRC link so they can be on standby in November in case of problems. __________