Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
LBNL, Berkeley, California, USA
Hardware has recently been installed in the Cornell Electron Storage Ring (CESR) to extend the capability of resonant microwave measurement of electron cloud density. Two new detector locations include aluminum beam-pipe in a dipole magnet and copper beam-pipe in a field free region. Measurements with both positron and electron beams are presented with both beams showing saturation of the electron cloud density in the aluminum chamber. These measurements were made at CESR which has been reconfigured as a test accelerator (CesrTA) with positron or electron beam energies ranging from 2 GeV to 5 GeV.
SLAC, Menlo Park, California, USA
LBNL, Berkeley, California, USA
CERN, Geneva, Switzerland
A high bandwidth feedback demonstrator system has been developed for proof of concept transverse intra-bunch closed loop feedback control studies at the CERN SPS. This system contains a beam pickup, analog front end receiver, signal processor, back end driver, power amplifiers and kicker structure. The main signal processing functions are performed digitally, using very fast (4GSa/s) data converters to bring the system signals into and out of the digital domain. The digital signal processing function is flexibly implemented in an FPGA allowing for maximum speed and reconfigurability for testing multiple control algorithms. The signal processor is a modular design consisting of commercial and custom components. This approach allowed for a rapidly-developed prototype to be delivered in a short time with limited resources. Initial beam studies at the SPS using the system prior to the CERN long shutdown one (LS1) have been very encouraging. We are planning several key upgrades to the system, including the signal processor. This paper describes these upgrades and reports on their progress.