摘要:

The recent development of the technology to build tabletop high power (terawatt) short pulse (picosecond) lasers has enabled the realization of the wakefield accelerator. The characteristics of a Nd:glasses laser for use as the laser driver for a wakefield accelerator are described. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49611

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Techniques for the control of femtosecond resolution phase and amplitude distortions during the amplification of ultrashort pulses are reviewed. Applications of a 4‐TW, 30‐fs, 10‐Hz, diffraction‐limited laser system are discussed and include ultrafast hard x‐ray generation for diagnostic imaging and field‐ionization‐driven XUV lasers. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49612

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A variation on a method demonstrated by Durfee and Milchberg is described for creating extended regions of controlled plasma density which are ideal for plasma wakefield acceleration experiments. Heating of an axially‐symmetric region of gas results in a supersonic expansion. The resultingcharge‐neutraldensity channel offsets the defocusing plasma density profile typically present during high‐field ionization of gases. High‐intensity, ultrashort pulses incident upon the channel ionize the gas and create waveguiding index profiles which can extend over hundreds of Rayleigh ranges. Immediately following the high‐field ionization, a well‐predicted plasma density should exist within the channel. Subsequent ultrashort pulses can be used to probe the properties of the channel. When used for plasma wakefield acceleration, energies in the hundreds of MeV can be expected. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49613

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Acceleration of charged particles along crystal channels has been proposed earlier in an attempt to achieve high acceleration gradient while at the same time to suppress excessive emittance growth. Recently we demonstrated that a particle in a generic focusing channel can in principle absolutely damp to its transverse ground state without any quantum excitation. This yields the minimum beam emittance that one can ever attain, &ggr;&egr;min=ℏ/2mc, limited only by the uncertainty principle. In this paper we discuss sources of excitation when a more realistic channel is considered, including bremsstrahlung and multiple Coulomb scattering. We investigate the possibility of colliding ultrahigh energy particles in such strong focusing channels without the need of a final focusing system, where the concept of luminosity departs from the conventional approach. We show that a high luminosity can be attained with a rather modest beam power. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49614

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

In the past two years, considerable progress has been made in development of the &mgr;+‐&mgr;−collider concept. This collider concept could permit exploration of elementary particle physics at energy frontiers beyond the reach of currently existing and proposed electron and hadron colliders. As a bench‐mark prototype, we present a candidate design for a high‐energy high‐luminosity &mgr;+‐&mgr;−collider, with Ecm=4 TeV, L=3×1034cm−2s−1, based on existing technical capabilities. The design uses a rapid‐cycling medium‐energy proton synchrotron, producing proton beam pulses which are focused onto two &pgr;‐producing targets, with two &pgr;‐decay transport lines producing &mgr;+’s and &mgr;−’s. The &mgr;’s are collected, rf‐rotated, cooled and compressed into a recirculating linac for acceleration, and then transferred into a storage ring collider. The keys to high luminosity are maximal &mgr; collection and cooling, and innovations with these goals are presented. Possible variations and improvements are discussed. Recent progress in collider concept development is summarized, and future plans for collider development are discussed. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49615

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The review is concerned with the following properties of Parametric X‐ray Radiation (PXR): PXR coherence, the row effect for PXR, spectral line width, PXR angular distribution, absolute differential yield, influence of incident electron energy and density effect on PXR properties, PXR properties at angular distance from Bragg directions, etc. Experimental setups on linacs and results of our measurements of PXR properties are discussed for incident electron energies 15.5; 25.7; 1200 MeV and for energies of PXR spectral lines between 5 and 400 keV. A smooth tuning of PXR spectral line energy is demonstrated by experiments. The experimental results are compared to calculations. Possibilities for the PXR applications are discussed. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49616

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We present one‐ and three‐dimensional calculations of the motion of relativistic electrons under the influence of an intense, linearly polarized laser and a static magnetic field, where strong acceleration of electrons is obtained. The electron dynamics in the case of a focused laser beam are compared to that of a pure plane wave. The focused laser beam tends to eject the electron due to the strong transverse ponderomotive force. It is shown that by depressing the laser beam’s central intensity the electron will remain within the focus. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49617

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A review is given of the various methods which can be employed for cooling particle beams. These methods include radiation damping, stimulated radiation damping, ionization cooling, stochastic cooling, electron cooling, laser cooling, and laser cooling with beam coupling. Laser cooling has provided beams of the lowest temperatures, namely 1 mK, but only for ions and only for the longitudinal temperature. Recent theoretical work has suggested how laser cooling, with the coupling of beam motion, can be used to reduce the ion beam temperature in all three directions. The majority of this paper is devoted to describing laser cooling and laser cooling with beam coupling. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49618

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

In order to control and manipulate internal phase space structure of charged particle beam, we present a general theory to use ponderomotive force between undulator and laser wave packet which is appropriately designed by employing coherent multiple discrete modes. We applied the method to an electron beam system which is shortly bunched in storage ring and demonstrated by computer simulation that the longitudinal energy spread is efficiently cooled in much faster time scale than the conventional synchrotron radiation cooling. The scattered laser light is found to preserve statistical characteristics of cooling related to the entropy exchange between beam and laser. The cooling in phase space is found to result fromentropicresonancewhich is different from the usual wave‐particle resonance. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49619

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Synchrotron radiation from clumped bunches ofNcharged particles is coherent at wavelengths comparable to and longer than the bunch length. The emitted radiation power increases byN2at these wavelengths. In this study we examine the possibility of enhanced cooling via this emission looking at beam sizes which are much greater than the critical wavelength for synchrotron radiation and much less. The possibilities for cooling in both regimes will be discussed. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.49597

出版商:AIP    

年代:1996

数据来源: AIP