Minutes of 28th FFIR meeting on 5/30/2001

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

(1) Superconducting FF quadrupole

(transparencies, 1 page, pdf ,120kB ) Tsuchiya explained his original idea on supercondicting quadrupole design which has been presented at the previous meeting. The small dipole inside of QC1 should be removed for background considerations. QC1 aperture can be increased to >10cm (inner radius) at the field gradient of 64.3T/m for disrupted(lower energy) beam to pass through. Serious problem is how to tranport these disrupted particles into a beam dump after QC1. We will ask Kubo-san whether he can design a dump line with the superconducting QC1 and disrupted beam.

Since QC2 can be small, the disrupted beam can be outside of the QC2. Field gradient of the QC2 is 22.4T/m and its inner radius can be 1cm. So, a warm magnet is more attractive for its conpactness. He will also design such warm magnet for QC2.

(1) Support tube R&D

(transparencies, 14 pages, pdf ,3.16MB ) Yamaoka presented test results with three configulations of the central part for a case of "single tube"; which are (a) 4 Alminium plates of 20mm width, 2mm thickness (I=1.9x104mm4), (b) 4 Al-plates of 20mm width, 4mm thickness (I=4.7x104mm4) and (c) 4 Al-plates of 70mm width, 5mm thickness (I=1.1x105mm4). He observed more resonances than simple-ANSYS calculations, where the central part was approximated by changing I-values only. In order to get more resonances he had to take account of real geomentries such as 4 Al-plate connecting two cantilevers. However, he could not reproduce observed patterns, although the larger I-value has better agreement between measurment and ANSYS-calculation. We need a further study to resolve this disagreement.

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