119768726
Towards a Dedicated High-Intensity Muon Facility
We discuss possible designs for a high-intensity, stand-alone muon source dedicated to and fully optimised for μSR studies. In particular, we focus upon the potential implementation of a new generation of high-power, but relatively compact and cost effective, proton drivers based on non-scaling fixed-field alternating gradient (ns-FFAG) accelerator technology. Initial considerations suggest that a facility with multiple optimised pion targets, each affording positron count rates approximately two orders of magnitude higher than existing pulsed muon sources, together with the potential of steady state operation at count rates comparable to the best existing sources, should be achievable at reasonable cost. The relative merits of a stand-alone muon facility with respect to those of current facilities which operate in symbiotic mode with other users of the proton driver are highlighted. The outstanding technical issues which must be addressed by both muon scientists and accelerator technologists are also considered.
6945786
GEANT4 VALIDATION STUDIES AT THE ISIS MUON FACILITY
GEANT4 provides an extensive set of alternative 
hadronic models. Simulations of the ISIS muon production 
using three such models applicable in the energy range 
of interest are presented in this paper and compared with 
the experimental data.
2407099
Impact of the Energy of the Proton Driver on Muon Production
Simulations studies have been carried out to examine the 
impact of the energy of the proton driver on muon production. 
The muon flux is calculated as a function of proton 
energy over a wide range, which covers the energies at the 
existing muon and neutron facilities worldwide. The muon 
and higher energy pion yields are normalised per beam current 
and accelerator power. The case of a higher energy of 
the proton driver at the ISIS muon facility is also examined.
47006332
MATERIAL STUDIES FOR THE ISIS MUON TARGET
The ISIS neutron spallation source uses a separate muon 
target 20 m upstream of the neutron target for MuSR research. 
Because ISIS is primarily a neutron source, it imposes 
restrictions upon the muon target, which normally 
are not present at other muon facilities like PSI or TRIUMF. 
In particular it is not possible to use thicker targets 
and higher energy proton drivers because of the loss of neutrons 
and the increased background at neutron instruments. 
In this paper we investigate possible material choices for 
the ISIS muon target for increased muon yield.
122292873
Normal beam spin asymmetries during the G0 forward angle measurement
The vector analyzing power measured in elastic scattering of transversely polarized electrons from an unpolarized nucleon is directly proportional to the imaginary part of the two photon exchange amplitude. There has been recent interest in explorations of the two photon exchange amplitude, as the real part has been proposed as a possible resolution of the discrepancy between Rosenbluth separation and polarization observable measurements of the ratio of the electric to magnetic proton form factor. The vector analyzing power appears in the experiment as an azimuthal asymmetry. It has been measured previously in the SAMPLE and A4 experiment with different kinematics than those achievable with the G0 apparatus. As part of the systematic checks for the G0 forward angle measurement at TJNAF, the normal beam spin asymmetry in the G0 detector array was measured with a 3 GeV beam incident upon a liquid hydrogen target. The experimental configuration was identical to the standard G0 forward angle running except that the beam was transversely polarized in the plane of the accelerator. The data collected cover a range in center of mass angle from 19° to 37°, with an eight-fold azimuthal symmetry. About 30 hours of data were taken in this configuration, resulting in an extracted vector analyzing power with a precision of a few ppm, which may already be able to provide some constraint on model predictions.PACS: 13.60.-r Photon and charged-lepton interactions with hadrons – 14.20.Dh Protons and neutrons – 29.27.Hj Polarized beams in accelerators
31174956
Stabilized lasers for advanced gravitational wave detectors
Second generation gravitational wave detectors require high power lasers with more than 100 W of output power and with very low temporal and spatial fluctuations. To achieve the demanding stability levels required, low noise techniques and adequate control actuators have to be part of the high power laser design. In addition feedback control and passive noise filtering is used to reduce the fluctuations in the so-called prestabilized laser system (PSL). In this paper, we discuss the design of a 200 W PSL which is under development for the Advanced LIGO gravitational wave detector and will present the first results. The PSL noise requirements for advanced gravitational wave detectors will be discussed in general and the stabilization scheme proposed for the Advanced LIGO PSL will be described.