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.
1684890
Stabilized High Power Laser for Advanced Gravitational Wave Detectors
Second generation gravitational wave detectors require high power lasers with several 100 W of output power and with very low temporal and spatial fluctuations. In this paper we discuss possible setups to achieve high laser power and describe a 200 W prestabilized laser system (PSL). 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. Special emphasis will be given to the most demanding power stabilization requiremets and new results (RIN ≤ 4×10 −9 / √ Hz) will be presented.
103822523
SPIN STRUCTURE FUNCTIONS OF THE PROTON AND DEUTERON FROM SLAC EXPERIMENTS E155 AND E155X
Experiments E155 and E155X at SLAC were polarized deep inelastic scattering measurements of the parallel and perpendicular scattering asymmetries. We extracted the polarized structure functions g1 and g2 of the proton and deuteron. Both experiments made precision measurements through a wide range in x and Q 2 . These data fall into the kinematic range between existing world data and have good consistency with them. In combination with the other world data, the results for g1 allow increased constraint on NLO QCD ts to the polarized structure functions. For g2 no signicant world data existed before E155X. The E155X measurement provides information about the higher twist eects in the nucleon.
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
433803
Exploring the feasibility of a stand alone muon facility for muSR research
The current paper discusses possible designs for a high 
intensity stand alone muon source formuSR studies of condensed 
matter. In particular we shall 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. The technical issues which must 
be addressed are also considered.
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.
179132452
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