Transverse modes and instabilities of a bunched beam with space charge and resistive wall impedance

Transverse instability of a bunched beam is investigated with synchrotron oscillations, space charge, and resistive wall wakefield taken into account. Boxcar model is used for all-round analysis, and Gaussian distribution is invoked for details. The beam spectrum, instability growth rate and effects of chromaticity are studied in a wide range of parameters, both with head-tail and collective bunch interactions included. Effects of the internal bunch oscillations on the of collective instabilities is investigated thoroughly. Landau damping caused by the space charge tune spread is discussed, and the instability thresholds of different modes of Gaussian bunch are estimated.Comment: 10 p

Dynamics of magnetic fluid drop's shape in rotating and stationary magnetic fields

Abstract A drop of magnetic fluid was experimentally studied in a rotating magnetic field H r with the additional influence of a stationary magnetic field H s : The conditions of a drop break were studied with different values and directions of intensities between rotating and static magnetic fields. The results of the experiment were theoretically well grounded.

Modulator For Klystron 5045

The first modulator for a forinjector klystron of VEPP -- 5 is being tested now in BINP in Novosibirsk. The forinjector of VEPP -- 5 will involve a 510 MeV Linac consisting of four accelerating modules. The Klystron 5045 manufactured at SLAC [1] was chosen to drive the accelerating modules. This paper presents a design and some testing results of this modulator. I. INTRODUCTION The modulator is a conventional line type modulator with some supplementary characteristics. A simplified electrical layout of this modulator is shown in Fig. 3. The voltage value in a filter capacitor CF is determined by a phase-control system with six SCRs. The CF charging current is limited by three 500#H inductors connected to the primary winding of the rectifier transformer. In addition, this system provides "soft-start" capability and fast protection. The PFN is resonantly charged through a charging high-voltage SCR-switch (HV-switch), a charging inductor, and de-spiking circuits. The resonant PFN charge..