superconducting-magnet

Paper	Title	Other Keywords	Page
TUZMA02	Operation for LHC Cryomagnet Tests: Concerns, Challenges & Successful Collaboration	cryogenics, dipole, target, controls	84
	V. Chohan CERN, Geneva
	The LHC construction phase is coming to a close with installation work progressing rapidly and beam start-up foreseen by end 2007. For the testing of the 1706 LHC cryo-magnets in cryogenic conditions and its successful completion by early 2007,considerable challenges had to be overcome since 2002 to assure certain semi-routine tests operation at CERN. In particular, the majority of staff for tests and measurement purposes was provided by India on a rotating,one-year-stay basis, as part of the CERN-India Collaboration for LHC. This was complemented by some CERN accelerator Operation staff. While only 95 dipoles were tested till 2003, the efforts and innovative ideas coming from the operation team contributed significantly to the completion of tests of nearly all 1706 magnets by end-2006. Amongst these, certain pivotal ideas to stream-line the tests methodology as proposed and implemented successfully by the Indian Associates deserve a special mention. An insight into this as well an overall view of the tests operation will be given, together with an indication of some of the operation-related results from the tests programme.
	Slides
THPMA020	Ideal Coil-Shape for Perfect Field in Superconducting Sextupole Magnets	sextupole, quadrupole, dipole, vacuum	658
	P. R. Sarma DAE/VECC, Calcutta
	Coil dominated superconducting magnets have become essential components in high energy accelerators. Such magnets need to have very good field quality in order to preserve the beam emittance when it passes through the magnets a large number of times. It is well-known that the coil-shape generated by two displaced elliptic current distributions of opposite signs produce a perfect dipole field in the overlapping region. Similarly two intersecting concentric elliptic current distributions produce the perfect quadrupole field. The coil-shapes of practical superconducting magnets which are used in LHC, RHIC etc. are variations of such ideal designs. No mention of ideal coil-shape for a perfect superconducting sextupole magnet is available in the literature. In the present work we have explored the field produced by various coils shapes and found a coil shape which is capable of generating the perfect sextupole field. Parametric equation has been given for the x-y profile of the boundary of the coil cross-section. This finding should be useful in designing practical sextupole coils.
THPMA022	Design of the Proposed 250 Mev Superconducting Cyclotron Magnet	cyclotron, focusing, proton, radiation	661
	M. K. Dey, R. K. Bhandari, U. Bhunia, J. Chaudhuri, A. Dutta, A. Dutta Gupta, C. Mallik, S. Murali, J. Pradhan, S. Saha, S. S. Sur DAE/VECC, Calcutta
	VECC has proposed a project for the design and development of a 250 MeV superconducting proton cyclotron, which may be used in therapy. In this paper we describe the preliminary design calculations for the superconducting magnet. Hard-edge approximation method has been adopted for finding the poletip geometry to meet the basic focusing requirements of the beam. The uniform-magnetization method has been applied to calculate the 3D magnetic field distribution due to saturated iron poletips, to verify the beam dynamical issues and optimize the poletip geometry. GM type closed cryo-cooler technology is being considered for steady state liquifaction of evapourated He gas from magnet cryostat.
THPMA048	Study of Vacuum Related Problems During the Energization of K500 Superconducting Cyclotron	vacuum, cyclotron	694
	Z. A. Naser, D. L. Bandapadhaya, R. K. Bhandari, U. Bhunia, J. Debnath, M. Dutta, C. Mallik, S. Paul, A. Polley, J. Pradhan, A. Sur DAE/VECC, Calcutta
	The K500 superconducting cyclotron main magnet has been commissioned successfully in VECC, Kolkata. During the process of energization, it has been observed that there was vacuum deterioration in the cryostat vacuum chamber with excitations. Detail studies have been carried out to examine the occurrence of such a situation. The electro-magnetic stress in the cryostat wall due to Lorentz force increases with current, and is more pronounced in the median plane of cryostat wherefrom various penetrations come out. This could be the possible reason for the OVC vacuum degradation. The paper reports the observations on vacuum deterioration during energization. An extensive study has been carried out to understand and explain the situation.