4GLS Diagnostics Discussion Meeting, 14th May 2007

CDR design has obviously changed, but the diagnostic principles haven't changed. The

HACL Gun:

Gun energy - temp diagnostics line
Gun emittance - temp diagnostics line
Cathode emitted bunch length
Issues of run-up from low current to high current
(separate meeting!)

Assume built gun (check Cornell prototype): current measurements, beam centroid measurements, beam profile measurements, insertable screen/Fcup?
Interlocking issue - make sure screens don't go in at high current.

HACL Injector:

Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list item.

Boris/Rob/Julian/Hywel to look at essential measurements

XUV Injector:

Collaboration with PITZ?
Fast amplitude stabilisation of RF amplitude and phase during 20 us RF pulse in XUV injector.

Output energy, chirp, bunch length - phase/voltage measurement of each cavity
Tranverse phase space measurement? May be a 'wish-list' item.
Include BC1 setup

Main Linac:

HACL team - measurements list: (Hywel)/Bruno/Rob/Alex

Need to think about the modes we will be running in:
XUV only: 1nC at 1kHz
HACL only: low current/high current/
XUV/HACL only:

Transfer matrix measurements - are they needed?

Energy Recovery/Dump

Measurement of energy recovery efficiency. Measurement of loss at level required?

HACL and IDs

Modes for commissioning again.
Profile monitors - low current with screens only, high current with alternative monitor - are they needed?
Tomography measurement - SR output resolution vs. resolution of other instruments for measuring of transverse profile, e.g. wavelength, diffraction etc.,

THz measurement in straight 1?
Streak cameras at short bunch length - 100 fs resolution under development, 10 fs
EO does not work at high current, use streak cameras at high current in upstream regions of the HACL ID arc.

How do we get the VUV-FEL to work? Bunch length, time overlap,

Discussion: Hywel/Frances/Neil

XUV-FEL

Emittance measurement is under control (Bruno!)
Seed laser diagnostics

Discussion
Neil/Steve/Frances/Bruno/Brian Sheehy/Graeme

IR-FEL:

Establish group: Boris/Bruno/Neil