ASTA roadmap to EPICS and other upgrades Remote monitoring and control DAQ Machine protection Dark current energy spectrometer

ASTA: Accelerator Structure Test Area High gradient X-band testing of accelerator structures (regularly exceeding 100 MV/m gradient) Up to ~200 MW peak power delivered to the structure by combining the power of two XL4 klystrons into a delay line SLED system. Consists of two modulators, two klystrons, delay lines for SLED, a radiation enclosure, PPS system, interlocked vacuum and cooling water systems, llrf system, diagnostics and data acquisition.. In the past used for S-Band RF gun testing incorporating a cathode laser system and small beam line with a beam spectrometer.

SRS 60 Hz AFG TWTK K llrf configuration I&Q MIXER I&Q MIXER SRS DG645 4 port combiner no SLED SLED

K K high power rf configuration

Breakdown rates vs gradient forward power reflected power faraday cup 1 faraday cup 2 Faraday cup signals register breakdowns and inhibit further pulses to prevent damage to the structure. Gradient is calculated.

DAQ/MPS existing configuration VAC controllers VAC1-2:Klystron VAC3-16: WG to DUT to load Power meters Faraday cup signals DUT FE/RE Klystron RE MPS Trigger inhibit(soft) Modulator trip(hard)

DAQ/MPS issues High bandwidth DAQ and MPS handled by one windows computer running several labview/C++ programs – data bottleneck causes missed MPS triggers – no data sharing or analysis possible during running – Complexity of the labview programs cannot be easily modified or scaled up

Control center electrically and acoustically noisy, hot

Upgrading ASTA Operational upgrades are required to satisfy existing and new user demands: SLAC X-band program, CERN, Japan, LCLS RF gun cathode characterization. Improved DAQ: user and operations access to real time and archived data: (EPICS a la LCLS, dedicated network). Correlate everything with everything else. Extract phase information to track breakdown locations within the structure. Real measurement of achieved gradient and dark current energy spectrum. Unattended and remote operations (a la NLCTA with a fire suppression system) Go to PAC/PAD llrf system Reestablish S-band RF and UV laser systems

DAQ/MPS proposed configuration VAC controllers VAC1-2:Klystron VAC3-16: WG to DUT to load Power meters Faraday cup signals DUT FE/RE Klystron RE MPS Trigger inhibit Modulator trip(hard)

DAQ/MPS upgrades EPICS handles most of the DAQ and MPS – Remote monitoring and operation – Complex labview programs continue to operate with EPICS IO Server for LabVIEW – Move LabVIEW functionality to EPICS

Gradient measurements Existing spectrometer is a damping ring magnet designed for 200 MeV gun testing. Unwieldy. Maximum of ~20-40 MeV of dark current expected for single small accelerator structure testing. which could be handled by a more compact spectrometer.

Use spare NLCTA chicane magnet 2 hours of work to put together (D. Walz)

Faraday cups on the straight ahead line to measure total charge Electrodes on offaxis lines for intensity Add an additional pumpout port to get the device closer to the structure Provision for small water cooling lines or lower duty cycle to achieve higher fields.

Where we are with DAQ/MPS Infrastructure: ADC modules, VME crate, terminal server, GPIB interface, EPICS computer, network switch and network are on hand or in place. Set up EPICS: Require some expertise in setup. Install and configure the EPICS software. Write or install drivers.

Where we are with phase extraction Feasibility study shows phase can be extracted. Further study ongoing to see if we have the resolution to determine breakdown location. Implementation is next (January 2011). Reflected energy envelope during a breakdown Computed phase

Upgrading ASTA: big ticket items Real measurement of achieved gradient and dark current energy spectrum: Magnet is available. Vacuum chamber in preliminary design stage. After $, its a one month timescale for final design and fabrication Unattended and remote operations (a la NLCTA with a fire suppression system) Modulators have been evaluated for fire protection. $$ BAS ASE changes to follow NLCTA precedent. PAC/PAD system being implemented in NLCTA. Can it be used for experimental DAQ? Reestablish S-band RF and UV laser systems. $$$ Waveguide can be reconnected. TS1 changed to dedicated S-band PPS upgraded and/or re-commissioned Laser systems EPICs will allow easy porting of LCLS apps