November 15-21, 1997

November 15 , 16 , 17 , 18 , 19 , 20 , 21

November 15

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	375.4 mA	707 minutes	265 A*minutes	0.281 nTorr	277.9 A*hours

• We had a weak earthquake at 1:43 PM, but there was no problem.

Beam current (blue trace) and lifetime (red one) around the clock.

November 16

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	374.4 mA	717 minutes	268 A*minutes	0.277 nTorr	285.1 A*hours

• We had a small beam loss of 77 mA at 10:12 AM. This was probably due to trapping of micro duct in the beam.
• We had a difficulty in injecting beams at 5:00 PM. This trouble was due to a fault (interlock action) with correction magnets for the beam transport line.

Beam current (blue trace) and lifetime (red one) around the clock.

November 17

• Machine study.
• Study on the low-emittance optics (90 degrees/cell) was carried out.
• After adjusting the beam transport line, we have greatly improved the beam filling rate (from 0.02 to 0.16 mA/sec) under the low-emittance optics.
• We achieved the maximum stored current of 150 mA at 8:04 PM.
• Measurement on the beam emittance was also carried out.

Beam profile which was monitored at the beamline BL-21 (5:27 PM). Beam current: 58.3 mA. Horizontal beam size was about one third than that under the routine (medium-emittance) optics, as was expected.

Improved beam filling rate. The filling rate was improved from 0.02 to 0.16 mA/sec.

Beam current (blue trace) around the clock.
Study on the low-emittance optics was carried out from 9:00 AM to 1:16 AM (Nov. 18).
We achieved the maximum beam current of about 150 mA under the new optics.

November 18

• User run.
• We have reduced the number of scheduled beam injections from three times to two per day.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	350.7 mA	693 minutes	243 A*minutes	0.277 nTorr	294.6 A*hours

Beam current (blue trace) and lifetime (red one) around the clock.

November 19

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	313.7 mA	751 minutes	236 A*minutes	0.302 nTorr	300.9 A*hours

Beam current (blue trace) and lifetime around the clock.

November 20

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	374.9 mA	715 minutes	268 A*minutes	0.272 nTorr	306.8 A*hours

• Beam dump happened at 5:08 PM due to an interlock action of the beamline BL-2 (so-called "Channel Dump"). It was due to a failure with a power supply for the interlock (of BL-2), and the power supply was replaced.
• Beam injection in the evening was interrupted by a radiation interlock (area monitor YEL-403) at 6:15 PM. The injection resumed at 7:00 PM after the interlock was reset.

Beam current (blue trace) and lifetime (red) around the clock.

November 21

• User run.
• The beam injection in this morning was interrupted (again!) by a high radiation level (area monitor YEL-403) of 87% at 9:17. We stopped this injection at the beam current of 370 mA, and started today's user run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	352.6 mA	783 minutes	276 A*minutes	0.245 nTorr	313.0 A*hours

Beam current (blue trace) and lifetime (red) around the clock.