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K Abe,
H Fuke,
S Haino,
T Hams,
M Hasegawa,
A Horikoshi,
A Itazaki,
K C Kim,
T Kumazawa,
A Kusumoto, [......],
R E Streitmatter,
J Suzuki,
Y Takasugi,
K Takeuchi,
K Tanaka,
N Thakur,
T Yamagami,
A Yamamoto,
T Yoshida, K Yoshimura
[show abstract]
[hide abstract]
ABSTRACT: In two long-duration balloon flights over Antarctica, the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) collaboration has searched for antihelium in the cosmic radiation with the highest sensitivity reported. BESS-Polar I flew in 2004, observing for 8.5 days. BESS-Polar II flew in 2007-2008, observing for 24.5 days. No antihelium candidate was found in BESS-Polar I data among 8.4×10(6) |Z|=2 nuclei from 1.0 to 20 GV or in BESS-Polar II data among 4.0×10(7) |Z|=2 nuclei from 1.0 to 14 GV. Assuming antihelium to have the same spectral shape as helium, a 95% confidence upper limit to the possible abundance of antihelium relative to helium of 6.9×10(-8)} was determined combining all BESS data, including the two BESS-Polar flights. With no assumed antihelium spectrum and a weighted average of the lowest antihelium efficiencies for each flight, an upper limit of 1.0×10(-7) from 1.6 to 14 GV was determined for the combined BESS-Polar data. Under both antihelium spectral assumptions, these are the lowest limits obtained to date.
Physical Review Letters 03/2012; 108(13):131301. · 7.37 Impact Factor
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U. Bravar,
M Bogomilov,
Y. Karadzhov,
D Kolev,
I. Russinov,
R. Tsenov,
L Wang,
F. Y. Xu,
S. X. Zheng,
R Bertoni, [......],
T. L. Hart,
D J Summers,
L. Coney,
R. Fletcher,
G G Hanson,
C. Heidt,
J. Gallardo,
S Kahn,
H. Kirk,
R B Palmer
[show abstract]
[hide abstract]
ABSTRACT: The Muon Ionization Cooling Experiment (MICE) is a strategic R&D project
intended to demonstrate the only practical solution to providing high
brilliance beams necessary for a neutrino factory or muon collider. MICE is
under development at the Rutherford Appleton Laboratory (RAL) in the United
Kingdom. It comprises a dedicated beamline to generate a range of input muon
emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a
pure muon beam. The emittance of the incoming beam will be measured in the
upstream magnetic spectrometer with a scintillating fiber tracker. A cooling
cell will then follow, alternating energy loss in Liquid Hydrogen (LH2)
absorbers to RF cavity acceleration. A second spectrometer, identical to the
first, and a second muon identification system will measure the outgoing
emittance. In the 2010 run at RAL the muon beamline and most detectors were
fully commissioned and a first measurement of the emittance of the muon beam
with particle physics (time-of-flight) detectors was performed. The analysis of
these data was recently completed and is discussed in this paper. Future steps
for MICE, where beam emittance and emittance reduction (cooling) are to be
measured with greater accuracy, are also presented.
10/2011;
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M. Ellis,
P R Hobson,
P Kyberd,
J J Nebrensky,
A Bross,
J Fagan,
T. Fitzpatrick,
R. Flores,
R. Kubinski,
J. Krider, [......],
A Sato,
T Yano,
M Yoshida,
C MacWaters,
L. Coney,
G Hanson,
A Klier,
D Cline,
X Yang,
D. Adey
[show abstract]
[hide abstract]
ABSTRACT: Charged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on 350 {\mu}m diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented. Comment: 43 pages, 38 figures
05/2010;
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M A C Cummings,
D Allspach,
L Bandura,
E L Black,
K W Cassel,
A Dyshkant,
D Errede,
S Geer,
J Greenwood,
M Haney, [......],
D Kubik,
Y Kuno,
W Lau,
S Majewski,
J Norem,
B Norris,
M Popovic,
M Reep,
D Summers, K Yoshimura
[show abstract]
[hide abstract]
ABSTRACT: The MuCool hydrogen-absorber R&D program is summarized. Prototype absorbers featuring thin aluminum windows and 'flow-through' or 'convection' cooling are under development for eventual power-handling tests in a proton beam and a cooling demonstration in a muon beam. Testing these prototypes and their components involves application of novel techniques.
Journal of Physics G Nuclear and Particle Physics 07/2003; 29(8):1689. · 4.18 Impact Factor
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D. M. Kaplan,
E. L. Black,
M. Boghosian,
K. W. Cassel,
R P Johnson,
S Geer,
C.J. Johnstone,
M Popovic,
S Ishimoto, K Yoshimura, [......],
A Dyshkant,
D Hedin,
D. Kubik,
C. Darve,
Y. Kuno,
D Errede,
M. Haney,
S Majewski,
M Reep,
D Summers
[show abstract]
[hide abstract]
ABSTRACT: A stored-muon-beam neutrino factory may require transverse ionization cooling of the muon beam. We describe recent progress in research and development on energy absorbers for muon-beam cooling carried out by a collaboration of university and laboratory groups.
09/2001;
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D. M. Kaplan,
E. L. Black,
K. W. Cassel,
S Geer,
M Popovic,
S Ishimoto, K Yoshimura,
L. Bandura,
M A Cummings,
A Dyshkant,
D. Kubik,
D Hedin,
C. Darve,
Y. Kuno,
D Errede,
M. Haney,
S Majewski,
M Reep,
D Summers
[show abstract]
[hide abstract]
ABSTRACT: A program is underway to develop liquid-hydrogen energy absorbers for ionization cooling of muon-beam transverse emittance. Minimization of multiple-scattering-induced beam heating requires thin windows. The first window prototype has been destructively tested, validating the finite-element-analysis model and the design approach. Comment: 3 pages, 3 figures, presented at the 2001 Particle Accelerator Conference (PAC 2001), June 18-22, 2001, Chicago, Illinois
08/2001;
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D.M. Kaplan,
E.L. Black,
K.W. Cassel,
S. Geer,
M. Popovic,
S. Ishimoto, K. Yoshimura,
L. Bandura,
M.A. Cummings,
A. Dyshkant,
D. Kubik,
D. Hedin,
C. Darve,
Y. Kuno,
D. Errede,
M. Haney,
S. Majewski,
M. Reep,
D. Summers
[show abstract]
[hide abstract]
ABSTRACT: A program is under way to develop liquid-hydrogen energy absorbers
for ionization cooling of muon-beam transverse emittance. Minimization
of multiple-scattering-induced beam heating requires thin windows. The
first window prototype has been destructively tested, validating the
finite-element-analysis model and the design approach
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001; 02/2001
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S. Ishimoto,
L. Bandura,
E.L. Black,
M. Boghosian,
K.W. Cassel,
M.A. Cummings,
C. Darve,
A. Dyshkant,
D. Errede,
S. Geer, [......],
C.J. Johnstone,
D.M. Kaplan,
D. Kubik,
Y. Kuno,
S. Majewski,
M. Popovic,
M. Reep,
D. Summers,
S. Suzuki, K. Yoshimura
[show abstract]
[hide abstract]
ABSTRACT: A feasibility study on liquid hydrogen (LH2) absorbers for muon ionization cooling is reported. In muon ionization cooling, an LH2 absorber is required to have a high cooling power greater than to cool heat deposited by muons passing through. That heat in LH2 can be removed at either external or internal heat exchangers, which are cooled by cold helium gas. As one of the internal heat exchanger types, a convection-type absorber is proposed. In the convection-type absorber, heat is taken away by the convection of LH2 in the absorber. The heat exchanger efficiency for the convection-type absorber is calculated. A possible design is presented.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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G. Gregoire,
G. Ryckewaert,
L Chevalier,
JM Rey,
MG Catanesi,
E Radicioni,
M. Castellano,
M Migliorati,
C. Vaccarezza,
P Fabbricatore, [......],
X Yang,
MAC Cummings,
D. Kubik,
Y. Onel,
SB Bracker,
LM Cremaldi,
R Godang,
DJ Summers,
GG Hanson,
A Klier
