Scaling of Energy Gain with Plasma Parameters in a Plasma Wakefield Accelerator

We have recently demonstrating the doubling of the energy of particles of the ultra-short, ultra-relativistic electron bunches of the Stanford Linear Accelerator Center [1]. This energy doubling occurred in a plasma only 85 cm-long with a density of {approx} 2.6 x 10{sup 17} e{sup -}/cm{sup -3}. This milestone is the result of systematic measurements that show the scaling of the energy gain with plasma length and density, and show the reproducibility and the stability of the acceleration process. We show that the energy gain increases linearly with plasma length from 13 to 31 cm. These are key steps toward the application of beam-driven plasma accelerators or plasma wakefield accelerators (PWFA) to doubling the energy of a future linear collider without doubling its length

Positron Production by X Rays Emitted By Betatron Motion in a Plasma Wiggler

Positrons in the energy range of 3-30 MeV, produced by x rays emitted by betatron motion in a plasma wiggler of 28.5 GeV electrons from the SLAC accelerator, have been measured. The extremely high-strength plasma wiggler is an ion column induced by the electron beam as it propagates through and ionizes dense lithium vapor. X rays in the range of 1-50 MeV in a forward cone angle of 0.1 mrad collide with a 1.7 mm thick tungsten target to produce electron-positron pairs. The positron spectra are found to be strongly influenced by the plasma density and length as well as the electron bunch length. By characterizing the beam propagation in the ion column these influences are quantified and result in excellent agreement between the measured and calculated positron spectra

Material Effects and Detector Response Corrections for Bunch Length Measurements

A typical diagnostic used to determine the bunch length of ultra-short electron bunches is the auto-correlation of coherent transition radiation. This technique can produce artificially short bunch length results due to the attenuation of low frequency radiation if corrections for the material properties of the Michelson interferometer and detector response are not made. Measurements were taken using FTIR spectroscopy to determine the absorption spectrum of various materials and the response of a Molectron P1-45 pyroelectric detector. The material absorption data will be presented and limitations on the detector calibration discussed

Special issue on second generation plasma accelerators

The above quotation is not an advertisement for an automobile magazine; rather it is one of the highlights of the experimental results presented at a recent workshop in Kardamyli, Greece and in this Special Issue. This is the second Special Issue of the IEEE TRANSACTIONS ON PLASMA SCIENCE devoted to the topic of plasma accelerators. The first one was over nine years ago!’ A brief comparison of these ‘T. C. Katsouleas, Ed., IEEE Tram Plasma Sci., vol. PS-15, pp. 85-255, 1987. two issues serves to summarize the tremendous progress in the field over this period

Adiabatic plasma Buncher

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome; Istituto Nazionale di Fisica Nucleare, Via E. Fermi, 40 Frascati / CNR - Consiglio Nazionale delle RichercheSIGLEITItal