The new 3 generation synchrotron light sources coming up are designed for a small transverse emittance. But the small beam size gives a low Touschek lifetime and calls for good beam stability. In some storage rings higher harmonic cavities are installed for bunch lengthening to overcome the lifetime limitations. The higher harmonic cavities also induce Landau damping that improves the beam stab...

The disassembly of the Unilac prestripper linac of the Wideröe type took place at the beginning of 1999. An increase of more than two orders of magnitude in particle number for the most heavy elements in the SIS had to be gained. Since that time the new High Current Injector (HSI) consisting of H-type RFQ and DTLstructures for dual beam operation was installed and successfully commissioned. The...

The LHC Low Level RF system (LLRF) is a complex multi-loop system used to regulate the superconductive cavity gap voltage as well as to reduce the impedance presented by RF stations to the beam. The RF system can have a profound impact on the stability of the beam; a mis-configured RF system has the potential of causing longitudinal instabilities, beam diffusion and beam loss. To configure the ...

As proton therapy becomes increasingly popular, so does the need for Monte Carlo simulation studies involving accurate beam line modeling of proton treatment units. In this study, the 24 beam configurations of the Mevion S250 proton therapy system installed recently at our institution were modeled using the TOolkit for PArticle Simulation (TOPAS) code. Pristine Bragg peak, spread out Bragg peak...

The 4 vane RFQ resonator with magnetic coupling windows as initial part of high-current Heavy Ion Linac for ITEP TWAC facility is presently under commissioning at ITEP. It was constructed for acceleration of ions with 1/3 charge to mass ratio to the energy of 1.57 MeV/u with beam current up to 100 mA. Additional beam dynamics simulations have been carried out for actual fields of the RFQ in ord...

Abstract The PADME experiment is designed to search for a hypothetical dark photon A ' produced in positron-electron annihilation using bunched positron beam at the Beam Test Facility of INFN Laboratori Nazionali di Frascati. expected sensitivity -photon mixing parameter ? 10 -3 , mass ? 23.5 MeV/ c 2 after collecting ? 13 positrons-on-target. This paper presents detector status commissioning J...

The new 1.4 MeV/u front end HSI (HochStromInjektor) of the Unilac accelerates ions with A/q ratios of up to 65 and with beam intensities in emA of up to 0.25 A/q. The maximum beam pulse power is up to 1300 kW. During the stepwise linac commissioning from April to September 1999 the beam behind of each cavity was analysed within two weeks. A very stable Ar beam out of a volume plasma source MUCI...