1. TRT HV System status and plans for LS1 LPI Moscow, K. Zhukov

2. outline HV problems review February 2012 breaks December 2012 breaks Crates configuration Jolanta: over/undershoot events Schedule for LS1 visits and works Plans for HV system works in LS1

3. HV problems in 2012 It caused shortcut in UPS line which was tripped. February 2012. Crate 003 (EC A) PS dropped. The crate didn’t tripped but had damages on the board surfaces. February 2012. Crate 004 (EC A) PS had the same damages. All misbehaved cells were changed Few small problems with individual cells. Bottom crate in Barrel rack dropped twice during 10 days -> dust in the PS board surface. December 2012. Crate 010 (Barrel) dropped.

4. February 2012 problems It’s seems there was shortage 450 V pin to the ground. It lead to some destruction of the board surface. Valera A. found some remains of electrolyte which caused the shortage. It was some defect in capacitor. The both crates 003 and 004 were recovered successfully. The opened part of the HV pins was covered with lacquer for protection. The PFCs were repaired in Dubna and set back in the PS3500s. To be check: both crates were in the same rack -> External factor? The both crates 003 and 004 were recovered successfully. The opened part of the HV pins was covered with lacquer for protection. The PFCs were repaired in Dubna and set back in the PS3500s. To be check: both crates were in the same rack -> External factor?

5. December 2012 problems In December we had problems with bottom crate 010 in Barrel. It happened twice during 10 days. In both cases damages were caused by some external debris or dust. It caused shortcut in the HV diodes -> diodes overheating -> breaks On the surface of the PS3500 board small debris of Al and dust were found. It points that we should think about HV rack cleanliness (see 2013 plans). The crate was recovered successfully. The surface of the board was covered with protection lacquer. On the surface of the PS3500 board small debris of Al and dust were found. It points that we should think about HV rack cleanliness (see 2013 plans). The crate was recovered successfully. The surface of the board was covered with protection lacquer.

6. HV crates status End-cap ABarrelEnd-cap C Crate 006 (OLD)Crate 009 (NEW)Crate 002 (OLD) SC508 3SC508 10SC508 5 PFC board (NEW) PFC board (OLD, Upgraded) Crate 005 (OLD)Crate 010 (NEW)Crate 008 (OLD) SC508 4SC508 2SC508 6 PFC board (OLD, Upgraded)PFC board (NEW)PFC board (OLD, Upgraded) USA 15, sparesSR1, TRT SETUP HVSR1, Jola’s firmware test Crate 003Crate 007Crate 004 SC508 SC508 X, LVs problems PFC board (OLD,Upgraded)PFC board (OLD)PFC board (OLD, Upgraded)

7. Over/undershoot events (Jolanta)

8. HV system 2012 1.Spare HVM modules were received and calibrated. Ready to use. 2.Spares pool is full. Enough components and spares. 3.UPS line in USA15: There was problem that we had 10A protective element on UPS line and crate have 16 A fuse on input. If there’s trip of crate UPS line would trip. Now it’s OK. For two crates this protective element has 32 A limit. 4.Vitaly Shutov started preparing HV firmware upgrade of SC508 to work with higher baud rate. 5.All crate’s breaks were repaired successfully. November experience said when there’s HV crate trip it’s needed 40-60 mins (thanks to Andrei) to change it for spare one and switch them back to work with TRT.

9. Timetable for LS1

10. 1.Revise of all HV crate PS3500. Inviting Valera A. for a week to check PS3500 boards for any misbehaves. + over/undershot events explanation. 2.Covering power supply boards with HV lacquer to prevent debris or dust shortcuts. Other maintenance. 3.Cleaning HV racks from dust and debris. Thinking about new ventilation panels in HV racks. Maybe installing some filters. 4.Calibrations of HV cells. Other measurements (stability, checking HV cables etc.) 5.Firmware upgrade for higher baud rate. 6.Devices for fuse burning. Possibility to use them in TRT (V. Kantserov)

11. Thank you very much!