I did a HV test on TM3 at TCS yesterday. HV Ramp up speed: 1KV per 5 minutes when below 30KV,1KV per 10 minutes from 30-36KV. There is no major spark below36 KV . I could see lots small and big vacuum response on IG1 and PNG2 when conditioning from 30-36 KV, especially when closing to 36 KV. However, At 36.4 KV, There is a big continuous spark occurred. It could not be stopped until I lowed the HV to 14KV. I have to ramp up from 14 KV again. This behavior on TM3 HV test is same as before we saw. The module can not pass 36KV at present condition. During the test., EL is tied to 60KV bias. The HV cover on TM3 top is installed. And, Service tray cover plate is installed on TM3. |