[esa-t474] FW: water flow/vibration test in ESA enclosure

[Woods, Michael B.]

Message ID: 144     Entry time: 10/01/2007 01:41:21 PM  
Author: Johnny, Carsten, Mike  
Type: Routine  
Category: Other  
Subject: vibration in ESA enclosure with water off  
 
 
we took Zygo data after Carsten turned off the water flow INSIDE the tunnel/enclosure in ESA (closed individual 
valves to 3B1-3B4, Wiggler, 3C1 and 3C2); Neslab water to BPMs was off for all of these measurements.
Another set was taken after the water flow was turned on again.  Here is a summary

                                      RMS (nm)
Run   comment         BPM4 (axis 0)  BPM7 (axis 2)      BPM3 (axis 3)
84   water off        486 nm         958 nm            48 nm
85   water on         548 nm         1071 nm           95 nm

So, an improvement of 12-13% for BPMs 4 & 7 (these are on movers), and a factor of 2 improvement
for BPM 3.  

More tests planned, shutting off/reducing flow rate of water into the tunnel/enclosure.
  

-----Original Message-----
From: Johnny Ng [mailto:jng at slac.stanford.edu] 
Sent: Monday, October 01, 2007 1:45 PM
To: Woods, Michael B.
Cc: Hast, Carsten
Subject: RE: water flow/vibration test in ESA enclosure


hi all,
turning off the water seems to have some effect - see http://efd-mo.win.slac.stanford.edu/T474/144
so I think it's worth repeasting the test reducing the flow rate into the enclosure.

Johnny