Pulsedfocusing recirculating linacs for muon acceleration
Abstract
Since the muon has a short lifetime, fast acceleration is essential for highenergy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linearmore »
 Authors:
 Muons, Inc., Batavia, IL (United States)
 Publication Date:
 Research Org.:
 Muons, Inc., Batavia, IL (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC), High Energy Physics (HEP) (SC25)
 OSTI Identifier:
 1166806
 Report Number(s):
 DOEMuons86351
 DOE Contract Number:
 FG0208ER86351
 Resource Type:
 Technical Report
 Country of Publication:
 United States
 Language:
 English
 Subject:
 43 PARTICLE ACCELERATORS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; linear; accelerator; recirculating; pulsed; ramped; magnets; colliders; muon; neutrino factories
Citation Formats
Johnson, Rolland. Pulsedfocusing recirculating linacs for muon acceleration. United States: N. p., 2014.
Web. doi:10.2172/1166806.
Johnson, Rolland. Pulsedfocusing recirculating linacs for muon acceleration. United States. doi:10.2172/1166806.
Johnson, Rolland. 2014.
"Pulsedfocusing recirculating linacs for muon acceleration". United States.
doi:10.2172/1166806. https://www.osti.gov/servlets/purl/1166806.
@article{osti_1166806,
title = {Pulsedfocusing recirculating linacs for muon acceleration},
author = {Johnson, Rolland},
abstractNote = {Since the muon has a short lifetime, fast acceleration is essential for highenergy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAGstyle magnets in the return arcs. A better solution, invented in this project, is to use combinedfunction dipolequadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of two. A patent application was filed for this invention and a detailed report published in Physical Review Special Topics. A scaled model using an electron beam was developed and proposed to test the concept of a dog bone RLA with combinedfunction return arcs. The efforts supported by this grant were reported in a series of contributions to particle accelerator conferences that are reproduced in the appendices and summarized in the body of this report.},
doi = {10.2172/1166806},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2014,
month =
}

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