60,295 research outputs found
The BaBar Electromagnetic Calorimeter: Status and Performance Improvements
The electromagnetic calorimeter at the BaBar detector, part of the asymmetric
B Factory at SLAC, measures photons in the energy range from 20 MeV to 8 GeV
with high resolution. The current status of the calorimeter, now in its seventh
year of operation, is being presented, as well as details on improvements made
to the analysis code during the last years.Comment: 6 pages, 15 figures, presented at the 2005 IEEE Nuclear Science
Symposium and submitted to the Conference Proceedings of the 2005 IEEE
Nuclear Science Symposiu
Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)
This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the
PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface
Recent Results from the RICE Experiment at the South Pole
We present a compilation of recent results, submitted to the 2003
International Cosmic Ray Conference (Tsukuba, Japan). These include: a) Revised
Monte Carlo estimates of the radiofrequency signals produced by electromagnetic
showers in ice, b) an updated search for ultra-high energy (UHE) neutrinos
based on detection of radio-wavelength Cherenkov radiation; such radiation
results from neutrino-induced electromagnetic showers in cold Polar ice, and c)
An in situ measurement of the index of refraction through the South Polar firn.Comment: Compendium of RICE collaboration submissions to ICRC0
The International Linear Collider
In this article, we describe the key features of the recently completed
technical design for the International Linear Collider (ILC), a 200-500 GeV
linear electron-positron collider (expandable to 1 TeV) that is based on 1.3
GHz superconducting radio-frequency (SCRF) technology. The machine parameters
and detector characteristics have been chosen to complement the Large Hadron
Collider physics, including the discovery of the Higgs boson, and to further
exploit this new particle physics energy frontier with a precision instrument.
The linear collider design is the result of nearly twenty years of R&D,
resulting in a mature conceptual design for the ILC project that reflects an
international consensus. We summarize the physics goals and capability of the
ILC, the enabling R&D and resulting accelerator design, as well as the concepts
for two complementary detectors. The ILC is technically ready to be proposed
and built as a next generation lepton collider, perhaps to be built in stages
beginning as a Higgs factory.Comment: 41 page
Ultrahigh Energy Cosmic Rays
This is a review of the most resent results from the investigation of the
Ultrahigh Energy Cosmic Rays, particles of energy exceeding 10 eV. After
a general introduction to the topic and a brief review of the lower energy
cosmic rays and the detection methods, the two most recent experiments, the
High Resolution Fly's Eye (HiRes) and the Southern Auger Observatory are
described. We then concentrate on the results from these two experiments on the
cosmic ray energy spectrum, the chemical composition of these cosmic rays and
on the searches for their sources. We conclude with a brief analysis of the
controversies in these results and the projects in development and construction
that can help solve the remaining problems with these particles.Comment: 40 pages, 27 figure
Cosmic-Ray Events as Background in Imaging Atmospheric Cherenkov Telescopes
The dominant background for observations of gamma-rays in the energy region
above 50 GeV with Imaging Atmospheric Cherenkov telescopes are cosmic-ray
events. The images of most of the cosmic ray showers look significantly
different from those of gamma-rays and are therefore easily discriminated.
However, a small fraction of events seems to be indistinguishable from
gamma-rays. This constitutes an irreducible background to the observation of
high-energy gamma-ray sources, and limits the sensitivity achievable with a
given instrument. Here, a Monte Carlo study of gamma-like cosmic-ray events is
presented. The nature of gamma-like cosmic-ray events, the shower particles
that are responsible for the gamma-like appearance, and the dependence of these
results on the choice of the hadronic interaction model are investigated. Most
of the gamma-like cosmic ray events are characterised by the production of
high-energy pi0's early in the shower development which dump most of the shower
energy into electromagnetic sub-showers. Also Cherenkov light from single muons
can mimic gamma-rays in close-by pairs of telescopes. Differences of up to 25%
in the collection area for gamma-like proton showers between QGSJet/FLUKA and
Sibyll/FLUKA simulations have been found.Comment: Accepted by Journal of Astroparticle Physic
Numerical and Theoretical Studies of Radiation from Plasma Dipole and its Applications
Department of PhysicsThe localized plasma dipole oscillation technique was first proposed by Kwon K. et al in 2016 as an efficient terahertz radiation source [1]. This can be achieved by cross-shooting two-color ultrashort laser pulses into plasma and can be applied for diagnostic purposes as well. The ensemble of charged particles oscillating like plasma dipoles radiate EM waves at plasma frequency (??p) with the narrowband spectrum and carry meaningful information about the bulk plasma. In particular, by measuring the frequency of radiated signals, local plasma density at the focused point can be detected. Comparing the new idea with the conventionally utilized techniques such as interferometry, reflectometry, and Langmuir probes [2-4], we insist that our method has numerous advantages as a technique for measuring the density [5]. Theoretical estimations accompanied by 1D, 2D, and 3D PIC simulations indicated that embedded plasma dipole oscillators show complex behavior leading to harmonic generations and many nonlinear effects that require further investigation. In this thesis, the dipole formation, radiation scheme, and density reconstruction measurements are reported and the investigations about magnetic field effects and harmonic generations are introduced briefly.clos
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