AB/BT Septa presentation for KEK visitors 22/9/2004

PS complex and septa overview

Jan Borburgh

AB-BT-Septa section leader

AB/BT Septa presentation for KEK visitors 22/9/2004

CERN Septa operating parameters• Vacuum: typically 10-9 mbar range, for LEIR and

AD <10-12 and <10-10 mbar respectively

• Magnetic septa currents: from 7 to 40 kA for pulsed septa, up to 2.8 kA for DC septa outside vacuum

• Electrostatic septa electric fields: up to 11 MV/m, cathode lengths from 720 mm up to 3 m

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

PS

PSB

AD

LINACs

CTF3

LEIR

ISOLDE

cv

East Hall

AB/BT equipment in PS complex

17 magnetic septa

2 electrostatic septa

3 magnetic septa

1 electrostatic septum

Ions for LHC ProjectPS Complex

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

Electrostatic septa

LEIR electrostatic septum (diagonal deflection)

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

Under vacuum magnetic septa

Stack of 4 booster extraction septa with the flexible strip line

Under vacuum infra-red bake out lamps

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

Septum exchange

Aligned chassis before plug-in (PS septum 31) installation

Septum installed in the PS ring

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

Radiation levels in the PS complexPS ring radiation dose rate after 32 hrs (2002)

1

10

100

1000

10000

uS

v/h

upstream

downstream

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

Design constraints due to maintenance of radioactive equipment

• Relative easy exchange of equipment in case of failure (plug in units)• Initial alignment with surveyors, no realignment in case of an

exchange• Quick disconnect vacuum flanges to speed up installation in

accelerator• Use of ‘radiation hard’ materials as much as possible• Minimize maintenance needs due to elastic construction and fixation of

coils for pulsed septa• Still tri-monthly exchange of insulation fluid of High Voltage

feedthrough of electrostatic septa in PS ring• Programmed exchange of electrostatic septa• Manual installation of flexible strip line connection for pulsed

magnetic septa • Manual quick disconnecting cooling water supply• Permanent installation of bake out system, except the for the

regulation electronics

PS complex and septa overview

AB/BT Septa presentation for KEK visitors 22/9/2004

SPS Septa maintenance and radiation related issues

Bruno Balhan

SPS extraction activities coordination

AB/BT Septa presentation for KEK visitors 22/9/2004

5 Magnetic Septa (MSE)

5 Electrostatic Septa (ZS)

Extractions for the SPS

3 Magnetic Septa Thin (MST)

West Extraction (LSS6)

5 Magnetic Septa (MSE)

5 Electrostatic Septa (ZS)3 Magnetic Septa Thin (MST)

North Extraction (LSS2)

6 Magnetic Septa (MSE)

East Extraction (LSS4)

CERN Accelerator ComplexSPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

Radiation Measurement in Extraction Areas.

Radiation evolution on the monitor PMIU603 (mSv).

Monitors implantation in the west extraction channel.

Radiation probes are installed close to the equipment.

SPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

Radiation levels for SPS extraction channels. North Extraction Dose Rate at about one meter after 30h of cool down.

These measurements are taken around the entire SPS ring after every run.

SPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

Maintenance and Intervention on SPS septa.

• Planned exchange/replacement guidelines in order to avoid interventions during runs (H.V cables, water filters, …)

• Remove and store equipments for long interventions, especially during replacement of radiation damaged cables (~ every 5years)

• Monitoring of critical parameters to assure correct operation and septa lifetime ( Spark rate, faults, beam losses, water quality, …)

• Use portable remote camera for interventions (motor calibration)

• Bunker for refurbishment and spreading of dose taken over several people (equipment specialists perform only expert tasks)

SPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

H.V. feedthrough replacement

• Diagnostics, five electrostatic septa in the same vacuum sector

• Intervention planning with people involved (physics coordinator, equipment experts, safety coordinator, radiation protection service, vacuum and transport services)

• Intervention preparation (actions, detailed radiation dose planning, spares,)

• Wait for radiation cool down and exact measurement before access

• Vacuum venting with dry N2 on equipment concerned

• Remove damaged HV feedthrough under constant N2 flow

SPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

H.V. feedthrough replacement

• Install “pre-conditioned” feedthrough (baked, HV tested, vacuum stored)

• Installation of mobile vacuum pumping groups

• Pumping, leak detection and removal of pumping equipment

• HV conditioning of equipment when correct vacuum level is obtained

• Hand over the equipment in “good shape” to the main control room

• Intervention analyses with involved people to improve/update procedure

SPS Septa maintenance and radiation related issues

AB/BT Septa presentation for KEK visitors 22/9/2004

Design issues of the SPS Magnetic Septa in LSS4

Wim Weterings

LSS4 Project engineer

AB/BT Septa presentation for KEK visitors 22/9/2004

AB/BT equipment in PS complexDesign issues of the SPS Magnetic Septa in LSS4

Main Design Issues

Quick disconnectPreventive maintenanceRadiation hard materials

Accessibility of componentsPre-alignment & Plug-in installation

AB/BT Septa presentation for KEK visitors 22/9/2004

Vacuum tank

Support structure

Bake-out system

RF Shielding

Support girder

Adjustable jack Ball bearingBus-Bar system

Motorization

Cooling circuit

Plug-in system

Contact elements

Personel protection cover Power feedthrough

Alignment target

Septum coil

Laminated yoke

Adjustable support feet

AB/BT equipment in PS complex

MSE septum magnet parameter

Septum thickness mm 17.25

Gap height mm 20

Maximum field T 1.508

Kick at 450 GeV/c mrad 2.249

Magnetic length m 2.237

B.dl max Tm 3.373

Peak current A 24,000

B.dl / I Tm/A 1.41 10-4

Total resistance m 3.48

Total inductance mH 84

Peak voltage V 80

Minimum rise/fall time ms 200

Magnet spacing mm 3,234

Design issues of the SPS Magnetic Septa in LSS4

AB/BT Septa presentation for KEK visitors 22/9/2004

AB/BT equipment in PS complex

MSE Magnet

Plug-In System

Magnet Cooling System

Power and Cooling Feedthrough

Design issues of the SPS Magnetic Septa in LSS4

AB/BT Septa presentation for KEK visitors 22/9/2004

Design issues of the SPS Magnetic Septa in LSS4

Dummy Septum structure for alignment

purpose in clean-room & SPS tunnel

AB/BT Septa presentation for KEK visitors 22/9/2004

AB/BT equipment in PS complexFast extraction channel in LSS4 – Extraction Septum

MSE Magnet

Pre-aligned Pumping Module

Support Feet

Magnet support feet

Control Cabling

Patch Panel

AB/BT Septa presentation for KEK visitors 22/9/2004

AB/BT equipment in PS complex

Pre-aligned support feet

Vacuum Pumping Module

Design issues of the SPS Magnetic Septa in LSS4

AB/BT Septa presentation for KEK visitors 22/9/2004

Unique Control & Bake-out

Connection

Control Cabling

Patch Panel

Girder Motorization

Local Cabling (periodically preventive

replacement)

Further documentation:AB-Note-2003-027-BTSL-Note-2002-014-BT http://sl.web.cern.ch/SL/BTGroup/EXsection/LSS4/LSS4.htm

Design issues of the SPS Magnetic Septa in LSS4