Chad and i did a leak check on TM1 heat shield circuit with new Nb#7 target installed. It took about 5 mins pump down the circuit to leak rate 0.0x E-9atm.cc/sec and 0.0x E-4 torr on leak detector.

All vacuum lines and joints which connected to the leak detector had been helium sprayed and they are leak  tight. Chad sprayed helium on each VCR joints for 2 seconds every time. During 45sec waiting time, there is no any response on leak detector. Chad repeated same test again for double checking and we got same result. Chad finally flushed the helium around the target heat shield for 10 seconds.we waited for 45minute and found no response on the leak detector. The heat shield circuit is leak tight at this stage. I will do a helium pressure test on this circuit when TM1 is in CS and under vacuum.