# Presentation: 735842

## AGSELECTRICAL LEGACY ISSUES

**JON SANDBERG**
**Chief Electrical Engineer**
**Collider-Accelerator Department**
**Jsandberg@bnl.gov**
**Nov. 2004**

## Legacy Issues

**Primary WBS Areas Covered:**

**1.4.1.3.1 AGS                                 $2,044,060**

**1.4.1.2.1 Booster                           $   763,288**

**Total=  $2,807,348**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Legacy Issues

**Radiation Issues**
**ALARA Concerns**
**Magnet Coil Deterioration**
**Bus Insulation Replacement**
**Damaged Cable Insulation**
**Cable Tray Overload**
**Obsolescence**
**Power Supplies (PS)**
**Controls (PS)**
**Computer Interface**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Legacy Issues

**Lifetime Issues**
**Pulsed Power Supplies**
- Many PFN Components are subject to failures based on Accumulated pulses. Component Replacement required to insure Future Reliable Performance
**New Performance Criteria**
**Power supplies**
**P.S Controls**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Radiation Issues

-  Radiation Burden requires Quicker Access and Shorter Repair times for Ring Components such as Injection and Extraction PFN’s (pulse forming networks)
- MTTF (mean time to failure) and MTTR (mean time to repair) of Equipment must be Improved
- Electrical Hipot results show a steady degradation of Main Dipole Coil Insulation.  High intensity running in the Booster historically requires the replacement of One Magnet per Year.

**Radiation Issues**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Radiation Issues

- Unused Cables were often not removed in Ring trays to reduce personnel radiation Burden.
- Many Cables Show signs of Radiation Damage.
- Manipulation of Cables in Trays has been restricted to reduce further damage to insulation
- New Cable runs will require cleaning out existing Tray as well as some additional  Tray.
- Many Signal Cables use Teflon insulated Connectors.

**Radiation Issues**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Obsolescence

**Power Supplies**
- Some Key Power Supplies are Antiquated and require upgrades.  The F10 ejector is composed of 1960’s components that are no Longer Available.
- Switchmode Supplies Bought in the early Nineties utilize Obsolete Components.
- Controls and Computer Interfaces for Many Power Supplies are from the Early 1970’s.  Components are No Longer Available.  Reliability is Questionable.  Repair and Trouble Shooting is very Time Consuming.

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Lifetime Issues

**Pulse Forming Networks**
- PFNs are Located in the Booster and AGS Rings adjacent to the F3 (booster) and A5 (AGS) Kickers.  This makes repair difficult and time consuming.
-  The service life of the pulsed power devices is limited by the number of pulses delivered and the operating condition, such as voltage, pulse current, repetition rate, and the environment.
- The F3 and A5 Kickers have been operating in a radiation environment and above their nominal electrical ratings.

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Lifetime Issues

**Pulse Forming Networks**
**Changes Include**
-  Rebuilding of A5 (AGS) Kicker PFN’s.  Replacement of Capacitors and Thyratrons and radiation damaged Cabling. Investigate Schemes to lower operating Voltage Or Increase Component Ratings
- Component changes in the F3 Kicker (different Capacitors and possibly different Coils) will reduce system impedance and decrease Voltage Levels.
- Reducing the Voltage level will increase the Capacitor Lifetime.

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## New Performance Criteria

- Higher Booster Extraction Energy would Increase the Voltage stress on the Booster F3 Kicker
- Redesign of AGS F10 (56% more Current) and F5 (47% more Current) Ejector Magnets will require larger PS’s.
- Synchronization of the Booster A5 and A10 Kicker will require new PLC designs
- Digital Scopes are required to better Monitor and Synchronize the Extraction and Injection Kickers.  This will help improve beam transfer efficiency.

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## New Performance Criteria

- The AGS Spill Ripple will be reduced with the Introduction of a Second Active Filter
- Reduce Ripple with Improved J10 (AGS)  Dump Bump Power Supply.  This will allow the use of the Dump during the entire Acceleration Cycle and Reduce Uncontrolled Radiation Losses

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## AGS Main Magnet Bus

**AGS Main Magnet Bus**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster - RSVP Mechanical Issues

**Magnet Coils - Preparation for High Intensity**

**Half Cell Coil Repairs:**
- 1998 May C7 half cell
- 2000 Sept F7 half cell
- 2002 Sept D7 half cell
- 2003 Oct C5 half cell
- 2004 Aug E7 half cell
-    (discovered 2002)

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster - RSVP Mechanical Issues

**Booster Magnet Coil Preparation for High Intensity**
- Booster Magnet Coils have failed due to radiation damage to epoxy fiberglass insulation
- New coils for two magnets are on hand with internal Kapton wrap to improve radiation resistance – new coils will use Kapton as well
- Procurement lead time is 9 to 12 months
- Magnets will be repaired as failures occur – repair time 10 to 14 days.

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster F7 Damaged G10

**Booster F7 Damaged G10**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster C5 Damage

**Booster C5 Damage**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster C5  Damage

**Booster C5  Damage**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Booster F7 Coil

**Booster F7 Coil**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## AGS A5 Injection Kicker

- ~ 0.95 meter

**AGS A5 Injection Kicker**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## AGS Magnet History

**AGS Magnet History**

## Obsolete PS Controls

**Obsolete PS Controls**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## F10 Ejection Power Supply

**F10 Ejection Power Supply**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Controls Interface for Ejector PS’s

**Controls Interface for Ejector PS’s**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Obsolete  Interface

**Obsolete  Interface**

**F5 & F10 Computer**
**Interface**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## F10 Cable Sleeve

**F10 Cable Sleeve**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## AGS Cable Tray

**AGS Cable Tray**

- Damaged and Unused
- Cables Should be
- Removed before
- High Intensity Running

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## AGS RC Bypass Assemblies

**AGS RC Bypass Assemblies**

- J. Sandberg, BNL             AGS-Booster Electrical Issues

## Conclusions

**Conclusions**

- Load Changes required for reliable High Intensity Running necessitate  several new power supply procurements
- ALARA concerns and increased usage make changes to some in Ring components, such as PFNs, necessary.
- Adding new cables to some Tray within the AGS Ring would exacerbate existing Radiation Damage to Insulation.  Damaged cables must be removed and some new Tray added.
- Magnet Coils which exhibit poor HiPot test results should be replaced before a long High Intensity Run Begins.
- Antiquated  Electronics must be replaced to insure reliable trouble free operation.

- J. Sandberg, BNL             AGS-Booster Electrical Issues