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Title: A permanent magnet quadrupole magnet for CBETA

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Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
Report Number(s):
R&D Project: KBCH139; 18031; KB0202011
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: 8th International Particle Accelerator Conference (IPAC17); Bella Center, Copenhagen, Denmark; 20170514 through 20170519
Country of Publication:
United States

Citation Formats

Witte H., Tsoupas, N., Mahler, G., Cintorino, J., Berg, J. S., and Wanderer, P.. A permanent magnet quadrupole magnet for CBETA. United States: N. p., 2017. Web.
Witte H., Tsoupas, N., Mahler, G., Cintorino, J., Berg, J. S., & Wanderer, P.. A permanent magnet quadrupole magnet for CBETA. United States.
Witte H., Tsoupas, N., Mahler, G., Cintorino, J., Berg, J. S., and Wanderer, P.. Sun . "A permanent magnet quadrupole magnet for CBETA". United States. doi:.
title = {A permanent magnet quadrupole magnet for CBETA},
author = {Witte H. and Tsoupas, N. and Mahler, G. and Cintorino, J. and Berg, J. S. and Wanderer, P.},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun May 14 00:00:00 EDT 2017},
month = {Sun May 14 00:00:00 EDT 2017}

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  • In this paper rare-earth quadrupole lenses for focusing channel of ion linacs are presented. Authors have developed nonorganic lens conception and fabrication technique which allows to produce high-fidelity lenses for various applications. These lenses have comparatively higher level of permissible integral radiation exposure and they can be placed in high vacuum volume.
  • A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and themore » vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.« less
  • Magnetic quadrupoles have long been used in accelerator research for focusing high-energy particle beams. The advent of high-field, rare-earth permanent magnet materials has also spurred interest in permanent magnet quadrupoles (PMQ`s) since they are more lightweight and compact than their electromagnet counterparts and do not require power supplies or extraneous cooling. Here the authors study the potential use of closely-packed periodic permanent magnet quadrupoles for use in microwave tubes. In the most basic configuration, PMQ`s require four separate magnets in any given transverse plane, hence they are more expensive and complicated to assemble than conventional PPM stacks. Despite this fact,more » the stronger focusing available from PMQ`s may make them attractive for high-perveance beams, even at the low beam voltages generally of interest for compact slow-wave devices. Being iron-free systems, PMQ arrays may also lead to reductions in tube weight. The authors will compare and contrast PMQ and PPM stacks in terms of the beam focusing and beam quality that each provide and in terms of the comparative cost and difficulty of assembly. Results from two-dimensional beam envelope calculations and particle-in-cell simulations is discussed.« less
  • We describe the construction of a prototype hybrid permanent magnet dipole and quadrupole. The magnet consists of two concentric rings of Sm{sub 2}Co{sub 17} magnetic material 5 cm in length. The outer ring is made of 16 uniformly magnetized blocks assembled as a Halbach dipole and the inner ring has 32 blocks oriented in a similar fashion so as to generate a quadrupole field. The resultant superimposed field is an offset quadrupole field which allows us to center the field on the high-energy beam in the interaction region of the PEP-II B-factory. The dipole blocks are glued to the insidemore » surface of an outer support collar and the quadrupole blocks are held in a fixture that allows radial adjustment of the blocks prior to potting the entire assembly with epoxy. An extensive computer model of the magnet has been made and from this model we developed a tuning algorithm that allowed us to greatly reduce the n=3 17 harmonics of the magnet.« less
  • A superstrong permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens for the International Linear Collider (ILC). Our prototype PMQ can produce variable strengths from 3.5T to 24.2T in 1.4T steps. The magnetic center of the PMQ must not move more than a few microns during a 20% strength change to enable a Beam-Based Alignment (BBA) process to work. Our PMQ can be mechanically adjusted to suppress the center movement from more than 30{micro}m to less than 10{micro}m during strength changes.