Fermilab, Batavia, Illinois, USA
A Muon Collider promises unique opportunities both as an energy frontier machine and as a factory for detailed study of the Higgs boson and other particles. However, in order to achieve a competitive level of luminosity a number of demanding requirements to the collider optics should be satisfied arising from short muon lifetime and relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling. Basic solutions which make possible to achieve these goals with Nb3Sn magnet parameters are presented.
ANL, Argonne, Illinois, USA
Fermilab, Batavia, Illinois, USA
We report recent pulse-duration measurements of the APS PC Gun drive laser at both second harmonic (SH, 527 nm) and fourth harmonic (FH. 263 nm) wavelengths. The drive laser is a Nd:Glass-based CPA with the IR wavelength (1053 nm) twice doubled to obtain UV output for the gun. A Hamamatsu C5680 streak camera and an M5675 synchroscan unit are used for these measurements; the synchroscan unit is tuned to 119 MHz, the 24th subharmonic of the linac operating frequency. Calibration is accomplished both electronically and optically. Electronic calibration utilizes a programmable delay line in the 119 MHz rf path. The optical delay employs an etalon with known spacing between reflecting surfaces; this etalon is coated for the visible, SH wavelength. IR pulse duration is monitored with an autocorrelator. Fitting the streak camera image projected profiles with Gaussians, UV rms pulse durations are found to vary from 2.1 ps to 3.5 ps as the IR varies from 2.2 ps to 5.2 ps.
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Single-cell Nb3Sn cavities coated at Cornell University have demonstrated quality factors of 1010 at 16 MV/m and 4.2 K in vertical tests, achieving the performance requirements of contemporary modern accelerator designs. In this paper, we present results demonstrating the impact of the cooldown procedure and ambient magnetic fields on the cavity's ability to achieve these quality factors and accelerating gradients. The impact of the magnetic fields from thermoelectric currents, generated by thermal gradients across the cavity during cooldown, are shown to be equivalent to the impact of magnetic fields trapped from ambient sources. Furthermore, the increase in the residual surface resistance due to trapped magnetic flux, from both ambient sources and thermoelectric currents, is found to be a function of the applied RF magnetic field amplitude. A hypothesis for this observation is given, and conclusions are drawn regarding the demands on the cooldown procedure and ambient magnetic fields necessary to achieve quality factors of 1010 at 4.2 K and 16 MV/m or higher.
Fermilab, Batavia, Illinois, USA
Muons, Inc, Illinois, USA
SLAC, Menlo Park, California, USA
BNL, Upton, Long Island, New York, USA
LBNL, Berkeley, California, USA
UMiss, University, Mississippi, USA
The Muon Accelerator Program has completed a four-year study on the feasibility of muon colliders and on using stored muon beams for neutrinos. That study was broadly successful in its goals, establishing the feasibility of lepton colliders from the 125 GeV Higgs Factory to more than 10 TeV, as well as exploring using μ storage rings for neutrinos. The key components of the muon collider scenarios are a high-intensity proton source, a multi MW target and transport system for π capture, a front end system for bunching, energy compression and initial cooling of μ's, muon cooling systems to obtain intense μ+ and μ- bunches, acceleration up to multiTeV energies, and a collider ring with detectors for high luminosity collisions. For a neutrino factory a similar system could be used but with a racetrack storage ring for ν production and without the cooling needed for high luminosity collisions. Feasible designs and detailed simulations of all of these components have been obtained, including some initial hardware component tests, setting the stage for future implementation where resources are available and clearly associated physics goals become apparent.
Fermilab, Batavia, Illinois, USA
Illinois Institute of Technology, Chicago, Illlinois, USA
IIT, Chicago, Illinois, USA
ANL, Argonne, Illinois, USA
*Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Associate of Seville, Advanced Photon Source
'shkim@aps.anl.gov, shkim242@gmail.com