Date: Wed, 26 Jun 2002 00:46:00 -0400 (EDT)                                   
From: Dennis Wellnitz <wellnitz@astro.umd.edu>                                
Subject: HRI-SIM ThermoVac delay                                              
                                                                              
Hi all,                                                                       
                                                                              
There will be a delay in the HRI-SIM ThermoVac 1 cool-down of about           
one day.  After beginning pumping at 2pm and shroud cooling at 7 pm,          
without incident, when we began cooling the liquid helium plate with          
liquid nitrogen we discovered a leak.  It appears to be one of the            
inlet joints for the liquid helium plate, inside the vacuum chamber,          
and it appears to be induced by the temperature reduction.                    
                                                                              
We are now re-warming everything in preparation for opening the               
chamber at about 7pm Wednesday morning, and fixing the leak.  If all          
goes well we expect to begin cooling again Wednesday afternoon.               
                                                                              
We still hope to conclude all cold testing before July 4.                     
                                                                              
Let me know if you have any questions or comments.                            
                                                                              
        Dennis