Burle Leak Check3/19/2012

Jeff Williams

Jun Xie

System Info

• Ion gauge not functional due to baratron issues • Use RGA to view He background and total

system pressure• Initial test performed last week 3/15/2012 on

bottom side components, oven was on precluding chalice test

• Chalice tested 3/19/2012, and a 2nd test of other components also done at that time

• Pressure in the low 10 -7 Torr range on 3/19 after weekend pumping

Observations• No change in helium background during testing

in static condition• There is an increase in helium and other gases

(H2, N2) when hi vac valve is actuated (closed)• Pressure increase from approx. 2E-7 to 2E-6 in

10 minutes with hi vac closed• No discernable difference in level of helium

increase whether helium just sprayed in the valve area or not prior to valve actuation

Next Step

• Do one final test with a helium leak detector

• Close hi vac valve and record pressure vs. time. If outgassing, the rate of rise should decay over time. If a leak is present the rate of rise should remain consistent.