A theory of transition free-electron laser ~FEL! driven by an electron bunch of finite longitudinal length is presented. It is shown that one can introduce concepts of a long, a short, and a very short bunch depending on the degree of correlation between the bunch effective length and the transition radiation formation length. It is obtained that a long Gaussian bunch produces an electromagneti...

Free electron lasers (FEL) need a very bright electron beam in three dimensions and a high peak charge density. In order to compress an initially longer electron bunch generated from the photoinjector, magnetic bunch compression systems are widely employed. In this paper, first harmonic RF linearization and its associated requirements are reviewed. Meanwhile it is also briefly discussed what is...

A prototype programmable bunch-by-bunch signal acquisition and processing channel with multiple applications in storage rings has been developed at SLAC. The processing channel supports up to 5120 bunches with bunch spac-ings as close as 1.9 ns. The prototype has been tested and operated in five storage rings: SPEAR-3, DA¨NE, PEP-II, KEKB, and ATF damping ring. The testing included such applica...

The use of manual (i.e., active) restraint systems (or seat belts) in cars has increased dramatically over the last several decades, changing from around 10% in the late 1970s to as much as 68% in the 1990s (Datta & Guzek, 1992; National Highway Traffic Safety Administration [NHTSA], 1996b). Several factors are responsible for this increase. One important determinant has been the passage of man...

By using an approach other than usual, we derive an exact closed-form expression for the symbol error probability (SEP) for arbitrary rectangular M-QAM signaling over flat Rayleigh fading channels. This has never been achieved before as the best-known SER for QAM up to date is only the results obtained for the square M-QAM. Our rectangular M-QAM result can be readily extended to find the result...

We have studied fast ion instability (FII) in the electron ring (HER) at KEKB. We introduce an application of Singular Value Decomposition (SVD) to study multi-bunch beam oscillations. The SVD analysis[1] has been performed for a matrix consists of vertical bunch positions in a turn-byturn and bunch-by-bunch to extract wave lengths which characterized the behavior of multi-bunch beam instabilit...

numerous date palm orchards in south kerman, iran were investigated during 2001-2003. symptoms of leaf die-back appeared as light brown stripes which began at leaf tips and extended to leaf ends. infected tissues were surface sterilized with 0.05% sodium hypochlorite and, plated on pda medium. isolated fungi were purified using hyphal tip method. on pda medium, fungal colony was fluffy, first c...

In high charge RF photoinjectors for wakefield two beam acceleration studies, due to the strong longitudinal space charge, bunch lengthening between the photocathode and photoinjector exit is a critical issue. We present beam dynamics studies of bunch lengthening in an RF photoinjector for a high charge electron beam and describe methods to compensate the bunch lengthening to various degrees. I...

1.1.1 Introduction For linear accelerators, a single bunch instability of a positron bunch due to electrons created by ionization of the residual gas was discussed in Ref. [1], where a coherent oscillation of both electrons and positrons grows from any small initial perturbation of the bunch distribution, e.g. from the statistical fluctuations due to the finite number of beam particles. This in...