Author: Mokhov, N.V.
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TUPRO028 Energy Deposition Studies for the Hi-Lumi LHC Inner Triplet Magnets 1078
 
  • N.V. Mokhov, I.L. Rakhno, S.I. Striganov, I.S. Tropin
    Fermilab, Batavia, Illinois, USA
  • F. Cerutti, L.S. Esposito, A. Lechner
    CERN, Geneva, Switzerland
 
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy through the US LARP Program, and by the High Luminosity LHC project.
After operation at the nominal luminosity, the LHC is planned to be upgraded to a 5-fold increased luminosity of 5×1034 cm-2s−1. The upgrade includes replacement of the IP1/IP5 inner triplet 70-mm NbTi quadrupoles with the 150-mm coil aperture Nb3Sn quadrupoles along with the new 150-mm coil aperture NbTi dipole magnet. A detailed model of the region with these new magnets, field maps, corrector packages, segmented tungsten inner absorbers was built and implemented into the FLUKA and MARS codes. Various aspects of the new design were studied: (i) thicknesses of tungsten absorbers; (ii) beam screen interruption in interconnects; (iii) crossing angle value and orientation, etc. In the optimized configuration, the peak power density averaged over the magnet inner cable width doesn’t exceed 2 mW/cm3, safely below the quench limit. For the integrated luminosity of 3000 fb-1, the highest peak dose of 35 MGy occurs in the corrector package CP, while for other magnets, the peak dose in the innermost insulators ranges from 20 to 30 MGy. Dynamic heat loads to the triplet magnet cold mass are calculated to be on a target 10 W/m level. FLUKA and MARS results agree within 10%.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO028  
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TUPRO029 Reducing Backgrounds in the Higgs Factory Muon Collider Detector 1081
 
  • S.I. Striganov, N.V. Mokhov, I.S. Tropin
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy through the DOE Muon Accelerator Program (MAP).
A preliminary design of the 125-GeV Higgs Factory (HF) Muon Collider (MC) has identified an enormous background loads on the HF detector. This is related to the twelve times higher muon decay probability at HF compared to that previously studied for the 1.5-TeV MC. As a result of MARS15 optimization studies, it is shown that with a carefully designed protection system in the interaction region, in the machine-detector interface and inside the detector one can reduce the background rates to a manageable level similar to that achieved for the optimized 1.5-TeV case. The main characteristics of the HF detector background are presented for the configuration found.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO029  
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TUPRO030 Mitigating Radiation Impact on Superconducting Magnets of the Higgs Factory Muon Collider 1084
 
  • N.V. Mokhov, Y.I. Alexahin, V.V. Kashikhin, S.I. Striganov, I.S. Tropin, A.V. Zlobin
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy through the DOE Muon Accelerator Program (MAP).
Recent discovery of a Higgs boson boosted interest in a low-energy medium-luminosity Muon Collider as a Higgs Factory (HF). A preliminary design of the HF storage ring (SR) is based on cos-theta Nb3Sn superconducting (SC) magnets with the coil inner diameter ranging from 50 cm in the interaction region to 16 cm in the arc. The coil cross-sections were chosen based on the operation margin, field quality and quench protection considerations to provide an adequate space for the beam pipe, helium channel and inner absorber (liner). With the 62.5-GeV muon energy and 2×1012 muons per bunch, the electrons from muon decays deposit about 300 kW in the SC magnets, or unprecedented 1 kW/m dynamic heat load, which corresponds to a multi-MW room temperature equivalent. Based on the detailed MARS15 model built and intense simulations, a sophisticated protection system was designed for the entire SR to bring the peak power density in the SC coils safely below the quench limit and reduce the dynamic heat load to the cold mass by a factor of 100. The system consists of tight tungsten masks in the magnet interconnect regions and elliptical tungsten liners optimized for each magnet.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO030  
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THPRI085 Target Station Design for the Mu2e Experiment 3970
 
  • V.S. Pronskikh, G. Ambrosio, M.R. Campbell, R.N. Coleman, G. Ginther, V.V. Kashikhin, K.J. Krempetz, M.J. Lamm, A. Lee, A.F. Leveling, N.V. Mokhov, V.P. Nagaslaev, A.M. Stefanik, S.I. Striganov, S.J. Werkema
    Fermilab, Batavia, Illinois, USA
  • L.M. Bartoszek
    Bartoszek Engineering, Aurora, Illinois, USA
  • C.J. Densham, P. Loveridge
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • K.R. Lynch, J.L. Popp
    CUNY, Bayside, New York, USA
 
  Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The Mu2e experiment at Fermilab is devoted to search for the conversion of a negative muon into an electron in the field of a nucleus without emission of neutrinos. One of the main parts of the Mu2e experimental setup is its Target Station in which negative pions are generated in interactions of the 8-GeV primary proton beam with a tungsten target. A large-aperture 5-T superconducting production solenoid (PS) enhances pion collection, and an S-shaped transport solenoid (TS) delivers muons and pions to the Mu2e detector. The heat and radiation shield (HRS) protects the PS and the first TS coils. A beam dump absorbs the spent beam. In order for the PS superconducting magnet to operate reliably the sophisticated HRS was designed and optimized for performance and cost. The beam dump was designed to absorb the spent beam and maintaining its temperature and air activation in the hall at the allowable level. Comprehensive MARS15 simulations have been carried out to optimize all the parts while maximizing muon yield. Results of simulations of critical radiation quantities and their implications on the overall Target Station design and integration will be reported.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI085  
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