1. 9/10/2018
News on operation
Second commissioning phase from 30th of March to 9th of April 2009.
Aline Curtoni, Claire Simon, Franck Peauger, Wilfrid Farabolini
Tatiana Pieloni, Massimo Petrarca, Valentine Fedosseev, Eric Chevallay,…
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini

2. What’s new from the 1st commissioning ?
9/10/2018
A laser system in a nearly perfect reliable working state (no longer use of the dark current)
The RF attenuator installed in the gun power distribution (much less dark current)
Phase of sections 2 and 3 re-adjusted (by 10o) to be at 88o from section 1
Powers of the earth field correctors made independent for the 3 sections
More stable RF power (modulator, LLRF)
Diagnostics made more friendly to use
But not yet the availability of the power phase shifter of the section 1 (its construction progresses carefully)
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 2

3. The power phase-shifter construction
Mode convertors successfully brazed at Bodycote
Sliding circular waveguides successfully brazed at Cern
Still one more brazing to perform (input and output waveguides), then welding of the bellows, assembling, LLRF test and installation
Installation tools and procedure from CERN drawing office
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 3

4. #10-CTF3 Committee – Wilfrid Farabolini
9/10/2018
RF Gun
Measures of beam current, size, position, energy as function of phase, focusing coils field, laser spot position on photocathode…
MTV
coils
BCM
Corr.
Beam size on MTV215 rather constant (s: 1.5 to 3 mm) vs. phase.
Beam position shifts down for phase < 150o
Energy evaluated with the DHG/DVG130 corrector to 5.7 MeV down to 3.5 MeV for phases < 145o (but this first computation doesn’t take into account the fringe field of the gun coils)
Looks very similar to the PHIN
Laser pulses 7 ns (10 bunches)
QE = 0.5%, 0.2 nC/bunch
UV Laser energy/bunch: 0.29 mJ (nominal 1.93)
Beam position on MTV215 as function of DHG/DVG130 intensity (effect of solenoids fringe field)
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini

5. #10-CTF3 Committee – Wilfrid Farabolini
9/10/2018
Phase scan
270 deg ?
Not fully understood
Was clearer with the dark current !
90o
180o
90 deg
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 5

6. RF signals and timing problems
9/10/2018
Problem: Beam energy was stuck bellow 90 MeV and very instable.
Solution: The laser pulse occurred too close to the end of the RF pulse, bunches entered the section when the electric field has started to decay.
RF pulse after compression by the BOC
Standing wave gun filling
RF pulse transmitted through the structure
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 6

7. Bunch to bunch energy spread
9/10/2018
3 ns train
Bunch train max energy : 140 MeV (nominal 170)
Already some ideas to make use of such a time-energy discrete structure in the TBTS
DE/E = 1.45 %
170 keV < DE < 370 keV
12 ns train
Bunches are energy resolved – 7 ns train
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 7

8. First measure of Twiss parameters with Quad scan
9/10/2018
First measure of Twiss parameters with Quad scan
Triplet
MTV390
Emittance still larger than the specified one (< 20 mm.mrad)
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 8

9. #10-CTF3 Committee – Wilfrid Farabolini
Alignment problems
9/10/2018
Survey to be resumed especially in the vertical plane
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 9

10. BPMs operational on OASIS
9/10/2018
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 10

11. Control/Command still to be completed
9/10/2018
Control/Command still to be completed
Not yet for us
The middle-ware
The actual front-end
The gun phase-shifter actuator (after the jamming of the stepping motor)
Where the C/C should be
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini

12. CALIFES beam reached for the first time the end of the TBTS line
9/10/2018
Et ce n’est pas un poisson d’Avril !
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 12

13. #10-CTF3 Committee – Wilfrid Farabolini
9/10/2018
Conclusion
Works in progress.
Thanks a lot to all the support teams for their prompt reactivity
Ready and enthusiastic to resume on the 2nd of June
16th April 2009
#10-CTF3 Committee – Wilfrid Farabolini 13