Chad and I did a leak check on TM1 Nb5 target heat shield circuit. The leak detector was connected to heat shield circuit.The pumping down  of the  circuit is very smooth.Base leak rate is 0.0xE-9atm.cc/sec,and the base pressure is 0.0xE-4 torr. Chad checked the helium flow downstairs .He sprayed helium to both up and down VCR joints 2seconds each time. There is no any response on leak detector(30 seconds waiting time). Both joints did the same test twice, no response . Finally, he flushed helium around the target for 10 seconds,and i didnt see any response on leak detector either.The heat shield circuit on TM1 Nb5 target is leak tight at this stage.