119298311
Dependence of quantum correlations of twin beams on the pump finesse of an optical parametric oscillator
The dependence of quantum correlations of twin beams on the pump finesse of an optical parametric oscillator is studied via a semi-classical analysis. It is found that the phase-sum correlation of the output signal and idler beams from an optical parametric oscillator operating above threshold depends on the finesse of the pump field when the spurious pump phase noise generated inside the optical cavity and the excess noise of the input pump field are involved in the Langevin equations. The theoretical calculations can explain the previously experimental results quantitatively.
26749894
Compensating the electron beam energy spread by the natural transverse gradient of laser undulator in all-optical x-ray light sources.
All-optical ideas provide a potential to dramatically cut off the size and cost of x-ray light sources to the university-laboratory scale, with the combination of the laser-plasma accelerator and the laser undulator. However, the large longitudinal energy spread of the electron beam from laser-plasma accelerator may hinder the way to high brightness of these all-optical light sources. In this paper, the beam energy spread effect is proposed to be significantly compensated by the natural transverse gradient of a laser undulator when properly transverse-dispersing the electron beam. Theoretical analysis and numerical simulations on conventional laser-Compton scattering sources and high-gain all-optical x-ray free-electron lasers with the electron beams from laser-plasma accelerators are presented.
73648727
Polarization control proposal for Shanghai deep ultraviolet free electron laser
In this paper, a fully coherent radiation option with controllable polarization is proposed for the Shanghai deep ultraviolet free electron laser (FEL) test facility. Intensive start-to-end simulation suggests that the two crossed planar undulators which generate the horizontal and vertical linear polarized FEL, should be placed as close as possible for avoiding the polarization performance degradation of the final combined FEL radiation. With the existence of the phase-shifter between the two crossed radiators. Fourier-Transform-Limited output radiation with 100 nJ order pulse energy, 5 Ps full pulse length and circular polarization degree above 90% could be achieved. (C) 2012 Elsevier B.V. All rights reserved.
119212313
FEL Polarization Control Studies on Dalian Coherent Light Source
The polarization switch of a free-electron laser (FEL) is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. And the elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical permanent undulator section, circular polarized FEL with pulse energy exceeds 100 μJ could be achieved at Dalian coherent light source.
119272921
Single-shot measurement of free-electron laser polarization at SDUV-FEL
In this paper, a division-of-amplitude photopolarimeter (DOAP) for measuring the polarization state of a free-electron laser (FEL) pulse is described. The incident FEL beam is divided into four separate beams, and four Stokes parameters can be measured in a single-shot. In the crossed-planar undulators experiment at the Shanghai deep ultraviolet FEL test facility, this DOAP instrument constructed in house responsed accurately and timely while the polarization-state of fully coherent FEL pulses were switched, which is helpful for confirming the crossed-planar undulators technique for short-wavelength FELs.
118693453
Nonintersecting Brownian motions on the unit circle. Part I: noncritical cases
122790632
Experimental study of longitudinal dynamics of space-charge dominated parabolic bunches
Longitudinal dynamics of space-charge dominated parabolic beams has been studied at the University of Maryland Electron Beam Transport Facility. In this paper we report results which emphasis experiment, while numerical simulation studies are presented in another paper in this proceedings. Excellent agreement is found between experiment, simulation and theoretical prediction.<<ETX>>
122601857
Experimental studies of longitudinal dynamics of space-charge dominated electron beams
A comprehensive experimental program was carried out at the University of Maryland Beam Transport facility to study the longitudinal beam physics of space-charge dominated bunches. This investigation included the behavior of (a) bunches with parabolic line charge profile, (b) bunches with rectangular line charge profile, and (c) local perturbations (slow and fast waves) in rectangular bunches. The major experimental results are presented in this paper.
42914481
Conceptual design of the NSLS-II injection system
We present the conceptual design of the NSLS-II injection system [1, 2]. The injection system consists of a low-energy linac, booster and transport lines. We review two different injection system configurations; a booster located in the storage ring tunnel and a booster housed in a separate building. We briefly discuss main parameters and layout of the injection system components.
29813748
Intrabeam scattering and touscheck lifetime for the optical stochastic cooling experiment at the MIT-Bates South Hall ring
A proof-of-principle experiment of optical stochastic cooling (OSC) at the MIT-Bates South Hall electron storage ring (SHR) has been proposed. To produce convincing cooling results, the ring will be run near 300 MeV. Beam emittance growth caused by Intrabeam scattering (IBS) is a major concern for the design of experiment. Touschek scattering imposes a dominant limit on beam lifetime. Evaluation of these effects is part of the design optimization process. Simulation analyses of cooling for a viable OSC experiment are presented.
55642268
Simulation of magnetized beams
The angular momentums of particles in a bunch of beam are of importance in many applications. Usually the angular momentums are related to the end field of solenoids. In electron cooling facilities the solenoid fields are widely used as they are found very helpful not only in focusing and guiding the charge particle beams but also in enhancing the cooling rates. The RHIC electron cooler is a challenging project because it requires a high performance facility including a solenoid with high quality strong field (1 tesla). Issues caused by the end fields of the solenoid have been studied to minimize the extra temperature and coherent motions. In this paper we report recent results in simulating the angular momentums of the electron beam and its application on the RHIC electron cooler