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Commissioning status and plans. Shinji Machida o n behalf of the beam commissioning team ASTeC /STFC/RAL 12 August 2010. Beam time. Run #1: 20-23 June 2010 Run #2: 12-15 July 2010 Run #3: 27-29 July 2010 Run #4: 3-6 August 2010 end of 4 sector Run #5: 13-15 August 2010 full ring
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Commissioning status and plans Shinji Machida on behalf of the beam commissioning team ASTeC/STFC/RAL 12 August 2010
Beam time • Run #1: 20-23 June 2010 • Run #2: 12-15 July 2010 • Run #3: 27-29 July 2010 • Run #4: 3-6 August 2010 end of 4 sector • Run #5: 13-15 August 2010 full ring • (Run #6: 18-24 August 2010) rf commissioning • Run #7: 30 August – 2 September 2010 rf available • Run #8: 7-10 September • Run #9: 15-18 September • Run #10: 24-26 September • Run #11: 2-3 October • Run #12: 10-13 October
Brief status • At the end of Run #6 (24 August) • Ready for acceleration. • At the end of Run #5 (15 August), • A full lattice which accepts a fixed momentum beam from 10.5+a to 20.5-b [MeV/c]. • Know time of flight in that momentum range. • At the end of Run #4 (6 August),almost done • Know a way to injection a beam for some equivalent momentum range (+/- 10%). • Measure cell tune vs relative momentum.
Overview (from upstream) • ALICE and Injection line (Bruno Muratori, et.al.) • Injection area • Orbit into the septum • Septum mapping and (x, x’) at exit • Kicker calibration • A beam in four sector • Tune measurement • Time of flight measurement • Optics matching.
Injection area (1)orbit into septum • Established a way to measure (x, x’) at the entrance of septum. • Beam orbit at the last two quadrupole in the injection line (Q17, Q18) is within ~1 mm in horizontal, that is within error bar. • In vertical, a few mm depending on tuning upstream. • In vertical, steering before the septum (V-06) is adjusted to increase a beam in the ring.
Injection area (2)Septum mapping • (x, x’) as a function of strength is reproduced. It is consistent with July data, although June data looks different. (x, x’) at entrance might be different in June. • For example, x’ vs septum setting below, • S1: 22 June • S2: 3 Aug • S3: 14 July • S4: ignore.
Injection area (3)(x, x’) at septum exit • (x, x’) at the exit of septum is not as designed. • Change of strength and rotation is not enough to get (x, x’) by Stephan or Scott. • Instead, David calculated kicker strength assuming (x, x’) given.
Injection area (4)kicker calibration • Polarity of kicker 1 and 2 is determined. K1 kicks outward and K2 kicks inward. • Calibration between kicker setting voltage and CT current is measured. • Kicker waveform need to be optimized. • Yellow: septum • Red: kicker1 • Blue: kicker2 • Green: beam
A beam in four sector • A beam went back through 4 sector with more reasonable settings. • QD/QF = 260/220 A, which should give 18.5 MeV/c equivalent beam. • Nominal kicker 1 and almost zero kicker 2, which is consistent with David’s calculation.
Tune measurement (1) • With nominal setting of QD/QF=260/220A, horizontal tune is 0.15-0.18, which is close to the design value 0.177 (hardedge) at 18.5 MeV/c. • Tune with +/-5%, 10% setting was not accurate. Later found out that continuous beam loss within 4 sector happened. • Tune measurement in June may have the same problem, namely beam loss.
Tune measurement (2) • Horizontal position at 7 consecutive cells.
Time of flight (1) • Measured BPM signal of E07-EBPM-01 and E23-EBPM-01 directly. • Signal is much lower than BPM in ALICE, which is strip line type. EMMA’s one is button. • With the scope we used, which is 10 GS (100 ps sampling), difficult to see change of ToF with various lattice setting. • 5 ps (max) per cell x 16 cell = 80 ps.
Time of flight (2) • Difference of cables = ToF between 5 and 23 cell • Signal is very small (5 mV/div.). • Yellow: E05 (5th cell) • Red: E23 (23th cell) • 100 ps/sample
Optics matching (1) • Found that beam loss in the 4 sector can be reduced with the last 4 quadrupole setting in the injection line (Q15, 16, 17, 18). • Meaning that need better optics matching. • Both Yuri’s empirical setting and Jaroslaw’s calculation with MAD-X reduced beam loss.
Optics matching (2) • Sum signal of the consecutive 7 cells. • With better matching (left) than (right).
Other remarks • “One” of EPICS BPM card seems working now. However, BPM data taking still relies on 7 cables, which gives 7 BPM planes (H or V). • Difficulty to expand momentum range seems mainly due to different (x, x’) from septum. • Overall, however, we understand EMMA much more in details.
Plans • Tomorrow, we start full ring commissioning. • Inject a 18.5 MeV/c equivalent beam. • Optics matching is important than we thought. • However, only YAG at E05 and E23 are available. • ToF measurement with different BPMs. • We may have additional 6 cables (planes) to measure BPM at the same time.
Data • Actual data is stored on http://www.astec.ac.uk/emmafiles/analysis/SortByDate/… • With eLog, you should be able to trace what is going on. http://alice.stfc.ac.uk/elog/alicelog/