Minutes of 30th FFIR meeting on 10/11/2001
The meeting was held in a room of 3-425 at KEK, 13:30-14:10, 10/11/2001.
We discussed on new final focus system (longer L*) , and present status of
support tube R&D.
(1) New final focus system (discussion)
N.Yamamoto just started to adjust longer L* by changing upstream Q's while final
doublets are unchanged since Yesterday. He could change L* from 4.25m to 4.35m
by adjusting only upstream Q's. For further change, he must adjust the final
doublets together with sextupoles. Since he understood various knobs at this
optics, he will optimize or maximize the L* until next meeting.
He also calculate parameters such as field gradient of final doublets for the
present case of L*=4.25m. The parameters will be passed to Tsuchiya-san for
designing a superconducting final quadrupoles. With this configuration,
backgrounds due to low energy beam-particles should be estimated at a dump line.
(2) Support tube R&D
He has been investigating a discrepancy between measured eigen frequencies and
calculated ones. He directly looked at signals of accelerometers on the specimen
while it was vibrated. Signal of the oscillator was very clear. However, the
signals of accelerometers have high frequency noises. Especially, the signal on
the top of the specimen was largely distorted at the first resonance. He
suspected that the oscillator itself vibrated 3-dimensionally. So, he will try to
fix it on floor.
The next meeting will be on 25 October (Thu.), 2001 13:30 - 15:00 at 3 gokan,