Minutes of 27th FFIR meeting on 5/16/2001

The meeting was held in a room of 3-425 at KEK, 13:30-14:00, 5/16/2001. We discussed on Superconducting FF-Q, the present status of support tube R&D, and the ACFA report.

(1) Support tube R&D (transparencies, 6 pages, pdf ,497kB ) Tauchi presented the status of the support tube R&D instead of Yamaoka since he was absent for Low Temperature Physical Society meeting. An improvement of a connection between two cantilevers has been studied for a case of "both-ends support tube". Since it seems to be difficult to make a rigid box structure of 1mm thickness by welding or by expensive wire-cut method, two 5mm-thick plates interleaving the cantilevers were proposed for the connection. Taking account of this structure, an ANSYS calculation shows a very similar response to the planned one. So he will make them for further study. Fundamental oscillation patterns were also shown for various cases of supports. Both symmetric and anti-symmetric modes can be excited in these patterns even if two ends oscillate in the same phase. After these prototype measurements, results will be summarized and we would like to publish it, especially on verifications of ANSYS calculations and a comparison between two-cantilevers and a "tube"-supports. Also, vibration-proof support will be studied.

(2) Superconducting FF quadrupole (transparencies, 1 page, pdf ,120kB ) Tauchi showed a transparency which Tsuchiya prepared and he could not attend the meeting because of the Low Temperature Physical Society meeting. As shown in previous meeting, locations, field gradients and lengths of QC1 QC2 are listed as follows;

   distance from IP  field gradient  length 
         m               T/m           m
QC1      4.3            64.3         3.35
QC2     12.53           22.4         4.0
QC1 and QC2 are superconducting magnets. The QC1 has 12cm of inner diameter and its magnetic center is horizontally shifted with 1cm by an additional dipole-coil in it in order to add a more space for exiting beam with 6m rad crossing. Because of a large distance of QC2, the exiting beam can outside of the QC2, which is very nice for no additional bend. Serious problem in this design is that synchrotron radiations must hit the dipole-coil, which can not be acceptable. Although the dipole-magnet may have an important role of dynamic correction of magnetic center, we should empty inside the QC1. We would like to ask him for changing the design.

The next meeting will be on 30 May (Wed.), 2001 13:30 - 15:00 at 3 gokan, 425.