Status and progress of the CTF 3 probe

Status and progress of the CTF 3 probe beam 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 1

Results of the last run (up to 14 th dec. 09) • Beam charge: • Immediately after photo-cathode regeneration 0. 7 n. C/bunch • After few days 0. 25 n. C/bunch (QE = 0. 3 %) • Emittance: the problem seems solved (e normalized < 20 mm. mrad) • Energy : still around 140 Me. V despite higher RF compression • Beam position stability: to be improved • BPM calibration : to be resume during next period 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 2

Emittance measurements Simultaneous automatic scan in X and Y • Use of the OTR screen is mandatory : improve yield with alumina deposition on the silicon screen. • Accurate tuning of the gun coils is necessary. The waist is very tiny (0. 1 mm) on OTR screen. Higher optical magnification used for better resolution(1. 75 instead of 0. 36) 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 3

BPM calibration 1/3 A complex electronic to be tuned. • Up to now only the sum signals demodulated on a diode were used • Problem with phase stability of the reference signal and/or position stability of the beam Re-entrant Cavity at CALIFE with 5 mm offset and charge = 0. 6 n. C Resolution : < 5 µm (simulated) with 0. 1 mm offset and charge = 0. 6 n. C Resolution : < 0. 5 µm (simulated) 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 4

BPM calibration Beam charge calibration is OK (obtained by varying laser power) 2/3 Beam position when delta signal is. . But more problematic when send to the dedicated electronics demodulated with a diode is fine (obtained with corrector scan) With diodes With I/Q demodulator Demodulated I/Q signal 11 th February 2010 Computed beam position as function of time 16 th CTF 3 Committee - Wilfrid Farabolini 5

BPM calibration 3/3 • Tuning of the electronics to be resume during next run (choice of reference frequency signal, attenuator settings…) • Possibly a real problem with beam position stability (I/Q have a much better resolution that diodes) • Laser position stability (transport line mirrors and lens to be investigated) • HV pulse from modulator MKS 30 known to have ripple (tuning to be resume) 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 6

THE POWER PHASE SHIFTER IS INSTALLED 180 Me. V Compression Accélération S 22 (d. B) Phase S 12 (deg) On place in the CLEX gallery 28/jan/2010 Reflected power vs. frequency for various positions 11 th February 2010 Déplacement (mm) phase/position relation (1 deg / mm) 16 th CTF 3 Committee - Wilfrid Farabolini 7

How does it work ? Movable Fixed Guided wavelength depends on the transverse waveguide size Cylindrical WG TE 01 no electric field on the walls ! TE 10□ Rectangular to circular mode convertor TE 01○ E Field 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 8

On going works Development of 2 new MTVs (Califes like) for the TBTS lines with Uppsala University To be installed before 15 th march Development of a user friendly interface for Califes on the same model as for TBTS in Labview by the EN/ICE group RF phase and power coupler calibration on the accelerating structures 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 9

Conclusions • We are ready to resume operations with better diagnostics and to experience the phase shifter. • Probe Beam should now be experienced in the ACS. 11 th February 2010 16 th CTF 3 Committee - Wilfrid Farabolini 10