The SuperB project has the goal to build in Italy, in the Frascati or Tor Vergata area, an asymmetric e+/eSuper Flavor Factory to achieve a peak luminosity > 10**36 cm-2 s-1. The SuperB design is based on collisions with extremely low vertical emittance beams and high beam currents. A source of emittance growth comes from the bunch by bunch feedback systems producing high power correction signa...

A new regime of laser wakefield acceleration of an injected electron bunch is described. In this regime, the bunch charge is so high that the bunch wakefields play an important role in the bunch dynamics. In particular, the transverse bunch wakefield induces a strong self-focusing that suppresses the transverse emittance growth arising from misalignment errors. The decelerating longitudinal bun...

A new bunch-by-bunch beam position measurement (BPM) prototype has been designed and built to monitor the beam instability and analyse the beam trip in the BEPCII (Beijing Electron-Positron ColliderII) machine. The broadband electronics system which employs fast analogy digital converter (ADC) and field programmable gate array (FPGA) can obtain the beam information bunch-by-bunch with high bunc...

The DSP-based bunch-by-bunch feedback system installed in the PEPII high-energy ring (HER) has been used to damp instabilities induced by unwanted higher-order modes (HOMs) at beam currents up to 605 mA during commissioning. Beam pseudospectra calculated from feedback system data indicate the presence of coupled-bunch modes that coincide with a previously observed cavity mode (0-M-2). Bunch cur...

Viticulture is widely practiced in dry regions, where the grapevine is greatly exposed to water stress. Optimizing plant water use efficiency (WUE) without affecting crop yield, grape and wine quality is crucial to limiting use of water for irrigation and to significantly improving viticulture sustainability. This study examines the use in vineyards of particle film technology (engineered kaoli...

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste [1]. LAYOUT AND DESIGN PARAMETERS The FERMI accelerator layout is schematically shown in Figure 1. It consists of an injector, four linacs, two bunch compressors, a laser heater, and a spreader used to direct the electron beam into one of tw...

The endeavour to reach higher brightness of electron beams in designs of future FEL is often challenged by the coherent synchrotron radiation (CSR) effect in bunch compression chicanes. Extensive studies on the CSR effects have shown that the 1D approximation of the CSR force is valid for a wide parameter regime. However, as the bunch gets increasingly compressed in the chicane, the behaviour o...

The proposed PEP II B factory at SLAC requires a feedback to damp out longitudinal synchrotron oscillations. A time domain, downsampled, bunch-by-bunch feedback system in which each bunch is treated as an oscillator being driven by disturbances from other bunches is presented as we review the evolution of the system design. Results from a synchrotron oscillation damping experiment conducted at ...

The installation of a harmonic cavity to provide bunch lengthening and thereby increase the Touschek lifetime is considered for the ESRF storage ring. Simulations with a particle tracking code have shown that for few bunch operation where the current per bunch is large – a strong lengthening already results from the coupling with the broad band impedance of the vacuum chamber. Therefore the net...

A PIC simulation of the interaction of a positive charged bunch with an e-cloud yields the wake kick from the electrons on the tail particles of the bunch. The wake is induced from a certain offset in the transverse position of the head parts of the bunch which perturbs the electron distribution. Such pre-computed wake functions of each offset part of the bunch are forming a matrix which could ...