Status of installed target

Preparation of “demonstrator” target

Chris BoothSheffield

25th January 2008

Chris Booth University of Sheffield 2

IntroductionAim was to have both systems ready by 20th January.A lot of minor problems and delays:• Over half the mechanical parts ordered via RAL &

DL and produced externally were not to specification.

• Most have been recoverable, but this has meant extra machining work– Diamond-edge seals sub-standard.– Mounting holes incorrectly centred on upper & lower

flanges.– Incorrect target orientation on shaft.– Magnet clamps incorrectly made.– Optics block (for second system) distorted.– …

Chris Booth University of Sheffield 3

Status of Installed Target & ControlsChecked out in R78 Wednesday 16th

• Stepper motor & interlocks ok.• Target actuated 1000 times ok.• Good vacuum (3.3×10–7 mbar).• Absolute position w.r.t. beam pipe measured.Moved to ISIS and connected Sunday 20th

• Several damaged fibres discovered. (Neither route nor protection were as had been requested.)

• Optics (approximately) set up.• Stepper motor & interlocks checked.• Target raised & lowered several times.• Operation from MICE LCR difficult without network.• “Incident” resulted in damaged IGBTs. Power supply

returned to DL, now repaired. (Better protection in future?)

Chris Booth University of Sheffield 4

Requirements for Operation of Installed Target• Adjustment of optical amplifiers (2 hours?)• Changes to interlock programming (1 hour?)• Cables and signals from ISIS: synchronisation,

local beam loss, beam current.• Matching receivers to above signals (gain,

termination, timing) (2 hours?)• Ethernet – essential to monitor temperatures,

voltages etc from LCR, and to control PSU.• Gate valve to be open. (Changes to control rack

(Tuesday?) plus reconnection inside ISIS.)• Procedure for personnel protection. (Limit switch

missing?)• And, of course, permission from ISIS to operate!

Chris Booth University of Sheffield 5

Commissioning of Target (Basic minimum)Start with stepper motor raised• Operate for few hundred actuations

– Check synchronisation with ISIS (50/64 Hz?).– Adjust optical amplifiers if required.– Check coil temperatures with ISIS cooling water.– Check readout of beam-loss and ISIS current.– Set to minimum dip depth.

Lower stepper motor to normal position and actuate• Increase dip until see beam loss

– Study stability of target and beam loss (how many pulses?)

• Gradually increase dip depth within allowed losses– Study correlation of loss with depth (and time?).– Other tests depend on readiness of beam monitors.– Do ISIS want a minimum number of pulses to check induced

radiation?– Other tests??

Chris Booth University of Sheffield 6

Preparation of Second TargetNote: Preparation of mechanics and electronics are not independent!!• Mechanics

– Stator wiring completed Friday 25th.– Check wiring, clean flanges & tube Monday.– Stator to DL Tuesday 9:00 a.m. for welding Tuesday (???), return to

Sheffield Wednesday?– Clean & assemble optics block, collimators etc Monday p.m.– Alignment of optics Tuesday-Wednesday– Assemble shaft Tuesday-Wednesday. (Maybe remove DLC coating from

target later??)– Modify bearing Wednesday p.m.– Complete assembly Thursday morning.– Minor parts (laser screen etc.) Thursday p.m.

• Electronics– Control crate wired, checked (without actuator) OK Friday 25th.– DAQ box to be finished Saturday 26th.– Quadrature amplifiers, 24-bit timer, PS crate ready DL Monday p.m.– Collect above 9:00 am Tuesday.– Interconnect, start debugging ASAP Tuesday (NB new printed circuits!)– (If problems with timer, leave till later – only needed for monitoring).– Connect full system to actuator Thursday p.m. Start optical amplifier

adjustment and debugging. Complete by end Friday?