LINAC

1
LINAC

• Werner Portmann
• Controls Pikett Training
• March 1st 2007

2
What is the LINAC?

• LINAC is the abbreviation for Linear Accelerator.
• The LINAC accelerates electrons, which are
  produced in an electron source, to an
  intermediate energy of 100 MeV.

3

• The Linac consists of an electron source and two
  accelerating sections.
• In the electron source (also called "electron
  gun") the electrons are pulled out of a hot wire
  (cathode) by applying a high voltage of 90 kV
  between cathode and anode.
• The two accelerating structures are each 5.2 m
  long and operate at an RF frequency of 3 GHz.
  They increase the energy of the electrons to 100
  MeV and the speed of the electrons to almost the
  speed of light.
• A 16 m long beam transport system, consisting of
  several magnets, guides the electrons towards the
  booster, into which they are injected with so
  called kicker magnets.
• The LINAC (inclusive control system) has been
  built as a turn-key system by the German company
  "ACCEL".

4
Klystron 1
Klystron 2
Modulator 1
Modulator 2
RF Hutch
5
(No Transcript)
6
(No Transcript)
7
VME Crates

• ALIRF-VME-GUN 7-slot TRENEW crate (inside tunnel)
  with obsolete VME boards (spares available)
• ALIRF-GPIB-GUN GPIB bridge (inside tunnel) for
  high voltage power supply (- 90 kV)
• ALIRF-PC-GUNB microIOC for RF phase shifter
  (electronical phase shifter), phase A and B
• not standard
  installation, see trouble shooting
• ALIRF-VME-MOD Modulator 1 and Modulator 2 control
  system
• ALIRF-VME-A Timing system for LINAC
• ALIRF-VME-AS RF phase shifter (mechanical phase
  shifters), Kly1 and 2, SPB
• ALIRF-VME-B Phase measurement, Post Mortem
  Installation
• ALIMA-VME-A Magnet control (obsolete ADA boards,
  spares available), OMS card FPU, PBU
• ALIMA-VME-B Magnet control

8
Specialties

• A Siemens PLC in rack 11.0.2 controls all LINAC
  Interlocks.
• A Siemens Operator Panel allows to change the
  interlock values (together with RF colleagues).
• The PLC Interlock Control is not able to detect
  the first fault! A First Fault Detection System
  is in planning (Post Mortem Analysis).

9
Magnet control crate ALIMA-VME-A

• Contains obsolete ADA boards. If they need to be
  replaced, check all the jumpers and switches!
• This crate contains an OMS board for the LINAC
  phase shifters too.
• 2 Projects
• A/MA/LI for magnet part
• A/RF/LI/LIPH for the
  OMS motor card (Phases)
• bump less reboot should be possible
• Emergency Stock

10
Timing (A) and Phase Shifter Crate (AS)

• ALIRF-VME-A
• ALIRF-VME-AS
• 2 systems in one crate!
• Be aware in case of rebooting!
• Known problem ALIRF-VME-AS
• Arc detectors are not read correctly
• (inverted one/zero in bi records)

11
Warning
You are not allowed to open the Modulator Racks
(LMOD1 and LMOD2)! Only the following persons
have the permission Fichte Werner Fitze
Hansruedi Jaggi Andreas Christian
Geislhart Pedrozzi Marco Horvat Mladen Tron
Wolfgang
12
Trouble shooting

• Ggeneral remark
• call RF pikett if necessary!

• GUN Hight Voltage
• if the GPIB communications hangs
• telnet ALIRF-GPIB-GUN, -gt reboot
• rmc ALIRF-VME-GUN, -gt reboot
• (do both /- simultaniously)

Modulator stays in state pulsing, but is switched
off Unknown reason (perhaps not working arc
reading) switch back to STANDBY then RESET and
try PULSING if no success, try OFF RESET PULSING
(needs preheating....)
13
Modulator problem
14
Trouble shooting (continue)
ALIRF-PC-GUNB (microIOC) portmann_at_pc4494
portmann more A/RF/LI/GUNB/README the files got
from cosylab, to control the digital phase
shifter of Chris Gough with serial control (RS
232) microIOC is ALIRF-PC-GUNB (machine
net) user root, passwd cosylab12 all epics
important files under /opt actual position of the
tar file /exchange/share/microIOC_phaseshifter/
Header /cvs/A/RF/LI/GUNB/README,v 1.1
2006/10/10 083526 portmann Exp