2/20/2016J-PARC1 Virtual Accelerator An Accelerator Simulator

June 16-27, 2008USPAS2 What is the Virtual Accelerator  Virtual Accelerator is an XAL Application  It provides feedback to other applications much like the beam in a real accelerator does  It works in reverse of a normal application  The online model acts as a beam and provides input to diagnostic signals  It uses EPICS control system signals to listen for magnetic field values and also to broadcast diagnostic signal responses  Useful for initial debugging of aplications

What the “VA” Does and Does Not Do  Simulates the real beam transverse centroid and beam size motion Provides realistic beam response to BPM signals Does not provide beam size information (but could)  Does not provide realistic longitudinal beam behavior to RF settings (assumes ideal RF setup)  Reacts to user inputs at the speed that the online model can run usually 1 Hz is easily obtainable – a credibal beam tuning operational rate

EPICS Interface to User / Applications  The portable channel access server is used to broadcast the signals for magnets and beam responses Need to build or obtain the PCAS for your cpu architecture  This allows development and testing of applications in a realistic configuration – no changes o the application are needed

VA Features  Can add random noise to BPM readbacks Provides realistic live beam jitter  Can add noise to magnet settings  Has the usual XAL sequence selection interface

VA Architecture  Continuous loop runs checking magnet field levels, calculating beam positions at BPMs and broadcasting them