841 research outputs found
Recent Progress of RF Cavity Study at Mucool Test Area
In order to develop an RF cavity that is applicable for a muon beam cooling
channel, a new facility, called Mucool Test Area (MTA) has been built at
Fermilab. MTA is a unique facility whose purpose is to test RF cavities in
various conditions. There are 201 and 805 MHz high power sources, a 4-Tesla
solenoid magnet, a cryogenic system including a Helium liquifier, an explosion
proof apparatus to operate gaseous/liquid Hydrogen, and a beam transport line
to send an intense H- beam from the Fermilab Linac accelerator to the MTA hall.
Recent activities at MTA will be discussed in this document.Comment: 4 pp. 13th International Workshop on Neutrino Factories, Superbeams
and Beta beams (NuFact11) 1-6 Aug 2011: Geneva, Switzerlan
Helical channel design and technology for cooling of muon beams
Novel magnetic helical channel designs for capture and cooling of bright muon
beams are being developed using numerical simulations based on new inventions
such as helical solenoid (HS) magnets and hydrogen-pressurized RF (HPRF)
cavities. We are close to the factor of a million six-dimensional phase space
(6D) reduction needed for muon colliders. Recent experimental and simulation
results are presented.Comment: 6 pp. 14th Advanced Accelerator Concepts Workshop 13-19 Jun 2010:
Annapolis, Marylan
Entanglement of orbital angular momentum states between an ensemble of cold atoms and a photon
Recently, atomic ensemble and single photons were successfully entangled by
using collective enhancement [D. N. Matsukevich, \textit{et al.}, Phys. Rev.
Lett. \textbf{95}, 040405(2005).], where atomic internal states and photonic
polarization states were correlated in nonlocal manner. Here we experimentally
clarified that in an ensemble of atoms and a photon system, there also exists
an entanglement concerned with spatial degrees of freedom. Generation of
higher-dimensional entanglement between remote atomic ensemble and an
application to condensed matter physics are also discussed.Comment: 5 pages, 3 figure
Virulence of Escherichia coli Isolates Obtained from Layer Chickens with Colibacillosis Associated with Pericarditis, Perihepatitis, and Salpingitis in Experimentally Infected Chicks and Embryonated Eggs
To evaluate the virulence of avian pathogenic Escherichia coli (APEC) isolates obtained from colibacillosis cases associated with pericarditis, perihepatitis, and salpingitis, the embryo lethality assay and experimental infection model in chicks were used in this study. According to the established criteria based on mortality in the embryo lethality assay for evaluating the virulence of E. coli isolates, 23 of the 26 APEC isolates associated with pericarditis and perihepatitis and 8 of the 20 isolates associated with salpingitis were found to be virulent. Isolate D137, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 92%, and isolate D445, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 17%, were used for the experimental infection. Four of the five 11-day-old chickens inoculated through the air sac with isolate D137 died 1 day postinoculation, and the challenge strain was recovered from the air sac, pericardial sac, or liver; however, colibacillosis lesions were found in only one of the five birds postmortem. All five chicks inoculated with isolate D445 survived for 7 days postinoculation and exhibited airsacculitis or pericarditis lesions at 7 days postinoculation; the challenge strain was not recovered from the lesions postmortem. The results obtained in this study suggest that the different APEC isolates tested cause illness in chickens through distinct pathogenesis
Evidence for a source size of less than 2000 AU in Quasar 2237+0305
Recently, OGLE team have reported clear quasar microlensing signal in
Q2237+0305. We have analyzed the microlens event of ``image C'' by using their
finely and densely sampled lightcurves. From lightcurve fitting, we can
unambiguously set the source size of \lsim 0.98 Einstein Ring radius as a
conservative limit. This limit corresponds to , if we adopt
obtained by a recent statistical study of
mean mass of lens object. This gives a clear evidence for the existence of an
accretion disk in the central region of the quasar.Comment: 11 pages, including 1 table and 3 figures, accepted to ApJ
The experimental program for high pressure gas filled radio frequency cavities for muon cooling channels
An intense beam of muons is needed to provide a luminosity on the order of 10(34) cm(-2)s(-1) for a multi-TeV collider. Because muons produced by colliding a multi-MW proton beam with a target made of carbon or mercury have a large phase space, significant six dimensional cooling is required. Through ionization cooling - the only cooling method that works within the lifetime of the muon - and emittance exchange, the desired emittances for a Higgs Factory or higher energy collider are attainable. A cooling channel utilizing gas filled radio frequency cavities has been designed to deliver the requisite cool muon beam. Technology development of these RF cavities has progressed from breakdown studies, through beam tests, to dielectric loaded and reentrant cavity designs. The results of these experiments are summarized
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