University of Chicago, Chicago, Illinois, USA
Cornell University, Ithaca, New York, USA
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
As we move to ultra-high brightness photocathodes and ultra-cold beams, we may become more sensitive to stochastic, point-to point effects such as disorder induced heating and the Boersch effect, given the failure of Debye screening. In this study, we explore the effects of stochastic scattering. Modern beam dynamics codes often approximate point to point interactions with a potential created by smoothing the charge over space, removing sensitivity to stochastic effects. This approximation is often used in beamline optimization, because it is much faster. We study the limits of validity of this approximation. In particular, we will simulate effects of stochastic space charge on a high brightness photoemission beamline, an ultrafast electron diffraction beamline with a photocathode temperature of 5 meV with a final beam energy of 225 keV. Emittance dilution in the transverse plane and transverse beam size relative to smooth space charge simulations will be presented.
WEXXPLM3
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
We will a give broad description of recent results from Cornell University on improving the state of the art in the production of high brightness photoemitted electron beams for future light sources and ultrafast electron scattering. We will also discuss recent results on improving the lifetime of photocathode for spin polarized electron beam and on the production of large area photocathodes for single photon detection applications
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
Cornell University, Ithaca, New York, USA
Algorithmic control of accelerators is an active area of research that promises significant improvements in machine performance. To facilitate rapid algorithm prototyping, we have developed a generic interface between accelerator controls, beam physics modelling software and modern scripting languages. The work-flow of a project using this interface begins with testing algorithms of choice offline in simulation. After off-line testing, the same code can be deployed on real machines via the Experimental Physics and Industrial Control System (EPICS) API. We include noise in our simulations in order to mimic realistic accelerator behaviour and to evaluate robustness of algorithms to experimental uncertainties and long-term drifts. The results of test cases of using this framework are presented, including emittance tuning of the Cornell Electron Storage Ring (CESR), correction of diurnal drift in CESR steering and orbit correction on CESR and the Cornell-BNL ERL Test Accelerator (CBETA).