November 8-14, 1997

November 8 , 9 , 10 , 11 , 12 , 13 , 14

November 8

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	377.0 mA	623 minutes	235 A*minutes	0.345 nTorr	235.9 A*hours

• We found a leak of insulation oil from one of the klystron power supplies. We made temporary repairs on it.

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

November 9

• User run.
• Operation status in this morning:
  

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	376.3 mA	635 minutes	239 A*minutes	0.329 nTorr	242.9 A*hours

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

November 10

• Machine study.
• We made the first trial operation of one of the low-emittance optics (phase advance: 90 degrees/cell). We succeeded to store the beam at 9:49 PM.
  The new PF ring can be operated under three low-emittance optics, together with a medium emittance optics (currently used for user runs). The beam optics, used today, is the moderate one which corresponds to the design beam emittance of 44 nm*radians. Also see "High-brilliance project of the PF storage ring".

Image from the beam profile monitor which showed successfull beam storege.
Beam current: 5.65 mA.

• The maximum beam current of 5.65 mA was stored under the low-emittance optics (90 degrees/cell) at 0:18 AM on Nov. 11.

Plot of the beam current (a signal from the DC current transformer as shown by an yellow trace) showing the successful beam storege under the low-emittance optics. Ordinate: beam current (10 mA/full), abscissa: time.

• New orbit feedback system was successfully tested during 3:50 - 8:26 AM on Nov. 11. (We fixed some problems that remained, and carried out final test).
  The orbit feedback system has come into operation under user runs from Nov. 11 !
• We also repaired the oil leak from a klystron power supply which occured on Nov. 8. (We thank Denkenseiki Corp. for their quick correspondence).

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

November 11

• User run.
• Operation status in this morning:

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	344.1 mA	661 minutes	227 A*minutes	0.316 nTorr	251.4 A*hours

• The new orbit feedback system, which is used to correct vertical beam movements, has come into operation today.

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

November 12

• User run.
• During the beam injection in this morning, we had a trouble with one of the power supplies for septum magnets (i.e. deflection magnets for injected beams). It took about three hours to look at and to repair it. The trouble was caused by a bad electrical contact around a knife switch for input AC line. We finished beam injection at 0:45 PM.

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

November 13

• User run.
• A water leak was found in a plant building (so called "Energy Center") for the linac. Repair works took place today. Beam injection, scheduled in the evening, was moved to 9:00 PM due to this work. (The repair works were actually finished at 3:47 PM).
• We had a beam dump at 9:22 PM, just after the beam injection. The beam was injected again.
• Operation status in this morning:

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	374.2 mA	643 minutes	241 A*minutes	0.381 nTorr	264.7 A*hours

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

November 14

• User run.
• Operation status in this morning:

  Time	Beam current	Beam lifetime	I*tau	Average pressure	Integrated current
  10:00 AM	376.4 mA	691 minutes	260 A*minutes	0.274 nTorr	270.9 A*hours

• We had a beam dump at 5:02 PM due to an interlock action (so-called "Channel Dump") with the beamline BL-10. This trouble was due to a fault with a solenoid valve of main beam shutter, and we replaced this part with a spare.

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

Proress in the vacuum conditioning due to irradiation of SR.
Products of the beam current and the beam lifetime are shown by red dots. Average vacuum pressures per unit stored current are shown by blue dots.