RF Bucket Reduction as an Experimental Tool for Beam Diagnostics and Manipulation

Recycler barrier RF buckets

The Recycler Ring at Fermilab uses a barrier rf system for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf systems, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity …

Implementation of synchronised PS-SPS transfer with barrier buckets

For the future intensity increase of the fixed-target beams in the CERN accelerator complex, a barrier-bucket scheme has been developed to reduce the beam loss during the 5-turn extraction from the PS towards the SPS, the so-called Multi-Turn Extraction. The low-level RF system must synchronise the barrier phase with the PS extraction and SPS injection kickers to minimise the number of particles lost during the rise times of their fields. As the RF voltage of the wide-band cavity generating the barrier bucket would be too low for a conventional synchronisation, a combination of a feedforward c…

用于飞秒电子束诊断的束流驱动横向偏转结构

Beam-Driven Transverse Deflecting Structure for Femtosecond Electron-Beam Diagnostics

提出一种束流驱动的横向偏转结构，利用领先驱动束在谐振腔阵列中激发长寿命尾场，对尾随的探测束施加时间相关的横向偏转，实现约1.6飞秒的时间分辨率，并有望达到亚飞秒量级。

用于纵向束流诊断的束流驱动谐振无源横向偏转器的设计准则

Design criteria for a beam-driven resonant passive transverse deflector for longitudinal beam diagnostics

提出一种无需外部射频源的束流驱动谐振无源横向偏转器设计准则，利用尾场零交叉实现高时间分辨率纵向诊断，在European XFEL布局中实现约33 fs分辨率。

Upgrades of beam diagnostics in support of emittance-exchange experiments at the Fermilab A0 photoinjector

The possibility of using electron beam phase space manipulations to support a free-electron laser accelerator design optimization has motivated our research. An on-going program demonstrating the exchange of transverse horizontal and longitudinal emittances at the Fermilab A0 photoinjector has benefited recently from the upgrade of several of the key diagnostics stations. Accurate measurements of these properties upstream and downstream of the exchanger beamline are needed. Improvements in the screen resolution term and reduced impact of the optical system's depth-of-focus by using YAG:Ce sing…

Basics of RF electronics

RF electronics deals with the generation, acquisition and manipulation of high-frequency signals. In particle accelerators signals of this kind are abundant, especially in the RF and beam diagnostics systems. In modern machines the complexity of the electronics assemblies dedicated to RF manipulation, beam diagnostics, and feedbacks is continuously increasing, following the demands for improvement of accelerator performance. However, these systems, and in particular their front-ends and back-ends, still rely on well-established basic hardware components and techniques, while down-converted and…