An anomalous damping or growth of transverse coupled bunch modes is observed in the Cornell Electron Storage Ring (CESR). The growth rates and tune shifts of these modes are a highly nonlinear function of current. Unlike an instability produced by the coupling impedance of the vacuum chamber, the magnitude of the growth rate first increases, then declines, as the beam current is increased. The ...

This study looked at regulated deficit irrigation (RDI) on leafhoppers in the genus Erythroneura (Erythroneura elegantula Osborn, or western grape leafhopper, and Erythroneura variabilis Beamer) (Hemiptera: Cicadellidae), which are serious pests of cultivated grape (Vitis vinifera L.) in California. RDI is an irrigation strategy that reduces irrigation during a critical point in the phenology o...

A new method of monitoring the luminosity has been developed at CESR. The method involves shaking one bunch at a speciic frequency and observing the resulting oscillations of the corresponding opposing bunch. In initial tests, measurements with 1% accuracy have been obtained in 1 second. Measurements of diierent bunches in a train shows bunch to bunch diierences with the optimum luminosity cond...

An anomalous damping or growth of transverse coupled bunch modes is observed in the Cornell Electron Storage Ring (CESR). The growth rates and tune shifts of these modes are a highly nonlinear function of current. Unlike an instability produced by the coupling impedance of the vacuum chamber, the magnitude of the growth rate first increases, then declines, as the beam current is increased. The ...

We explore scenarios for generating a linear time-correlated energy spread in the LCLS electron bunch, prior to the undulator, that is needed for optical (x-ray) pulse compression. The correlated energy spread (‘chirp’) is formed by generating an energy gradient along the length of the electron bunch using RF phasing and/or longitudinal wakefields of the accelerating structures. The sign of the...

Bunch compressors, designed to increase the peak current, can lead to a microbunching instability with detrimental effects on the beam quality. This is a major concern for free electron lasers (FELs) where very bright electron beams are required, i.e. beams with low emittance and energy spread. In this paper, we apply our self-consistent, parallel solver to study the microbunching instability i...

Objective: Yield components and genetic contribution have the most important in final yield and breeding programs of crop plants. For this purpose, 20 varieties of grapevines with Russia origin were evaluated in Urmia and Takestan research station (under full irrigation and drought stress). Methods: Twenty grapevine genotypes were evaluated in Urmia and Takestan research station (under full irr...

A bunch-by-bunch beam diagnostic system which consists of a high speed light shutter and an optical beam detector has been developed. Since the open/close time of the shutter is comparable to a bunch spacing of 2 ns, it is capable of picking out the light pulses from a particular bunch in a bunch train. The selected pulses can be analyzed with conventional optical beam diagnostic methods in ord...

The mechanism of longitudinal interaction of high-energy positrons of a bunch train and secondary emitted particles of electron cloud is analyzed. We consider the case when electron cloud in solenoidal magnetic field is built mainly due to multipacting process. Positron bunches have to use some amount of their kinetic energy to give electron cloud some temperature. The field, which is responsib...