2,304 research outputs found
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
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
Compact x-ray source based on burst-mode inverse Compton scattering at 100 kHz
A design for a compact x-ray light source (CXLS) with flux and brilliance
orders of magnitude beyond existing laboratory scale sources is presented. The
source is based on inverse Compton scattering of a high brightness electron
bunch on a picosecond laser pulse. The accelerator is a novel high-efficiency
standing-wave linac and RF photoinjector powered by a single ultrastable RF
transmitter at x-band RF frequency. The high efficiency permits operation at
repetition rates up to 1 kHz, which is further boosted to 100 kHz by operating
with trains of 100 bunches of 100 pC charge, each separated by 5 ns. The entire
accelerator is approximately 1 meter long and produces hard x-rays tunable over
a wide range of photon energies. The colliding laser is a Yb:YAG solid-state
amplifier producing 1030 nm, 100 mJ pulses at the same 1 kHz repetition rate as
the accelerator. The laser pulse is frequency-doubled and stored for many
passes in a ringdown cavity to match the linac pulse structure. At a photon
energy of 12.4 keV, the predicted x-ray flux is
photons/second in a 5% bandwidth and the brilliance is in pulses with RMS pulse
length of 490 fs. The nominal electron beam parameters are 18 MeV kinetic
energy, 10 microamp average current, 0.5 microsecond macropulse length,
resulting in average electron beam power of 180 W. Optimization of the x-ray
output is presented along with design of the accelerator, laser, and x-ray
optic components that are specific to the particular characteristics of the
Compton scattered x-ray pulses.Comment: 25 pages, 24 figures, 54 reference
A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment
The UCNA collaboration is making a precision measurement of the β asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be ϵ(overbar) = 0.9985(4)
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