37012340
Status of R&D energy recovery LINAC at Brookhaven National Laboratory
In this paper we present status and plans for the 20- MeV R&D energy recovery linac (ERL), which is under construction at Collider Accelerator Department at BNL. The facility is based on high current (up to 0.5 A of average current) super-conducting 2.5 MeV RF gun,single-mode super-conducting 5-cell RF linac and about 20-m long return loop with very flexible lattice. The R&D ERL, which is planned for commissioning in early 2009, aims to address many outstanding questions relevant for high current, high brightness energy-recovery linacs.
121575244
Absolute polarized H-jet polarimeter development, for RHIC
Status of the H-jet polarimeter development is reviewed. The preliminary results of atomic beam intensity and density measurements are presented.
118051242
Polarized H− Jet Polarimeter For Absolute Proton Polarization Measurements in RHIC
Status of the H‐jet polarimeter development is reviewed. A number of design issues are discussed including vacuum system, integration into the RHIC storage ring, scattering chamber, and uniform vertical holding field magnet design. The absolute proton polarization of the atomic hydrogen‐jet target will be measured to 3% accuracy by a Breit‐ systematic error contribution to the jet‐target polarization measurements is also discussed.
26164616
A new relative proton polarimeter for RHIC
An innovative polarimeter based on proton carbon elastic scattering in the Coulomb nuclear interference (CNI) region has been installed and commissioned in the Blue ring of RHIC during the first RHIC polarized proton commissioning in September, 2000. The polarimeter consists of ultra-thin C targets and four Si detectors. All elements are in a 1.6 meter vacuum chamber. This paper summarizes the polarimeter design issues and recent commissioning results.
40825691
SNS Ring Injection Stripped Electron Collection: Design Analysis and Technical Issues
This paper describes the simulation studies on the motions of stripped electrons generated in the injection section of the Spallation Neutron Source (SNS) accumulator ring and the effective collection mechanism. Such studies are important for high intensity machines, in order to reduce beam loss and protect other components in the vicinity. The magnetic field is applied to guide electrons to a collector, which is located at the bottom of the beam vacuum chamber. Part of the study results with and without considering the interactions between electrons and materials are presented and discussed. The final engineering design of the electron collector (catcher) Is also described.
73530718
SMALL GAP MAGNET PROTOTYPE MEASUREMENTS FOR eRHIC
In this paper we present the design and prototype measurement of small gap (5mm to 10 mm aperture) dipole and quadrupole for the future high energy ERL (Energy Recovery Linac). The small gap magnets have the potential of largely reducing the cost of the future electron-ion collider project, eRHIC, which requires a 10GeV to 30 GeV ERL with up to 6 energy recovery passes (3.8 km each pass). We also studied the sensitivity of the energy recovery pass and the alignment error in this small magnets structure and countermeasure methods.
17564383
Measurement models for time-resolved spectroscopy: a comment
We present an exactly solvable model for photon emission, which allows us to examine the evolution of the photon wavefunction in space and time. We apply this model to coherent phenomena in three-level systems with a special emphasis on the effects of the photon detection process.
119369099
Quantum trajectories of interacting pseudo-spin networks

We consider quantum trajectories of composite systems as generated by the stochastic unraveling of the respective Lindblad-master-equation. Their classical limit is taken to correspond to local jumps between orthogonal states. Based on statistical distributions of jump- and inter-jump-distances we are able to quantify the non-classicality of quantum trajectories. To account for the operational effect of entanglement we introduce the novel concept of "co-jumps".
18424039
Quantum control of atomic systems by time resolved homodyne detection
We describe the light-matter interaction of a single two level atom with the electromagnetic vacuum in terms of field and dipole variables by considering homodyne detection of the emitted fields. Spontaneous emission is then observed as a continuous fluctuating force acting on the atomic dipole. The effect of this force may be compensated and even reversed by feedback.
15461480
Moving Quantum Agents in a Finite Environment
We investigate an all-quantum-mechanical spin network, in which a subset of spins, the K “moving agents”, are subject to local and pair unitary transformations controlled by their position with respect to a fixed ring of M “environmental”-spins. We demonstrate that a “flow of coherence” results between the various subsystems. Despite entanglement between the agents and between agent and environment, local (non-linear) invariants may persist, which then show up as fascinating patterns in each agent’s Bloch-sphere. Such patterns disappear, though, if the agents are controlled by different rules. Geometric aspects thus help to understand the interplay between entanglement and decoherence.
16125330
Pattern formation in quantum Turing machines
We investigate the iteration of a sequence of local and pair unitary transformations, which can be interpreted to result from a Turing-head $(\mathrm{pseudospin}S)$ rotating along a closed Turing tape $(M$ additional pseudospins). The dynamical evolution of the Bloch vector of S, which can be decomposed into ${2}^{M}$ primitive pure state Turing-head trajectories, gives rise to fascinating geometrical patterns reflecting the entanglement between head and tape. These machines thus provide intuitive examples for quantum parallelism and, at the same time, means for local testing of quantum network dynamics.