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ASTA roadmap to EPICS and other upgrades. Remote monitoring and control DAQ Machine protection Dark current energy spectrometer. High gradient X-band testing of accelerator structures (regularly exceeding 100 MV/m gradient) - PowerPoint PPT Presentation
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ASTA roadmap to EPICS and other upgrades
Remote monitoring and controlDAQ
Machine protectionDark 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.
SRS60 Hz
AFG
AFGTWT K
TWT K
llrf configuration
I&QMIXER
I&QMIXER
SRSDG645
4 port combiner
no SLED
SLED
K
K
high power rf configuration
Breakdown rates vs gradientforward powerreflected powerfaraday cup 1faraday cup 2
Faraday cup signals register breakdowns and inhibit further pulses to prevent damage to the structure. Gradient is calculated.
DAQ/MPSexisting configuration
VAC controllersVAC1-2: Klystron
VAC3-16: WG to DUT to load
Power meters Faraday cup signalsDUT FE/REKlystron RE
MPSTrigger 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 centerelectrically and acoustically noisy, hot
Upgrading ASTAOperational 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/MPSproposed configuration
VAC controllersVAC1-2: Klystron
VAC3-16: WG to DUT to load
Power meters Faraday cup signals
DUT FE/REKlystron RE
MPSTrigger 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)
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 extractionFeasibility 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
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