DEVELOPMENT OF FAST CONTROLS FOR BEAM WIRESCANNER FOR SuperKEKB
Anindya Roy, VECC, Kolkata, India
Tomohiro Okazaki, EJIT, Tsuchiura, Japan
Naoko Iida, Kazuro Furukawa, KEK, Tsukuba, Japan
KEKWire ScannerHER(8 GeV/c)Belle

PF-ARe- BTe+, e- Linace+ BT
LER(3.5 GeV/c)
PF

WEPD26

 UsedU d forf Non-destructive
N d t ti monitoringit i off beambprofilefil A frame holding 100µm Tungsten wire forming X, Y &U wires perpendicular to beam
 A stepper motor drive to move the frame inside beam line A PMT with Plastic Scintillator to detect Bremsstrahlung
emitted due to interaction of wire with Beam
 A set of four wire-scanner for measuring beam emmittance& Twiss parameter for optics
 A control and data acquisition system, synchronized withbeam pulse timing

Existing system

Why new control?

 VME and CAMAC based hybrid system
 VME PowerCore 6750 CPU with Vx-Works 5.3
 CAMAC based Data acquisition system (e.g. ADC, DAC etc.)
 Using EPICS Base-3.13 version
 Not synchronised with LINAC Timing system
 Beam mode identification using special method
 IOC independent data acquisition process Uniform wire speed while scanning the beam
 Not suitable for acquiring
multiple beam mode data simultaneously 8 Gev LINAC, simultaneously, injects of e- and e+ beam of different
characteristics into
¾ KEKB high-energy ring (HER) – 8.0 GeV, 2nC¾ KEKB low-energy ring (LER) – 3.5 GeV, 2nC¾ Photon Factory (PF) – 2.5 GeV, 0.1nC¾ PF/AR – 3.0 GeV, 0.1nC

Hardware Architecture A wire-scanner data acquisition system, synchronized with LINACTiming system, for simultaneous measurement of beam profilesof multiple beam modes Simultaneous measurement reduces measurement time and hence
improves the overall efficiency of the transport line
 Simultaneous measurement helps
p in PF and PF/AR/
mode beamstudies without degradation of luminosity at KEKB!

New System
 Emerson MVME5500 CPU card, EPICS Base-3.14.12.1 and Vx-works 6.8

 VME based ADC (14bit, 15µsec conversion time), Scaler and DAC
 MRF’s event receiver module (VME-EVR-230RF) - synchronizing the data acquisition
process with LINAC timing system
 A LAN/GPIB converter to communicate with Pulse motor controller (PMC) and Digital
Multimeter (DMM) for control and data acquisition.
 ADC Gate generated by event receiver – simultaneous measurement of multiple
beam modes (pulse-to-pulse) Multispeed wire movement to minimize time of scan and maximize useful data Options to user for selecting beam modes for data acquisition
 Application specific EPICS record, compatible to SAD user interface
Special features¾ Wire scanner (WS) record
9 A waveform record with multiple input links (26, INPA….INPZ) for collecting data
9 A Ring Buffer,Buffer appending an array of data (from input links) on every scan
9 Provision for delay the processing – to ensure completion of ADC conversion (if LAM isabsent!)
9 Fields for defining number of SCALER, BPM (4 ADC per BPM) and wire-scanner ADC channel
9 Field for appending BEAM mode (event code) to data on every scan for identification
9 Option for resetting the buffer

Data Acquisition Strategy• Requirement:• Solution:

configuration of pulse generator (i.e. delay & timing event) for eachbeam mode to generate ADC Gate synchronized with beam pulse
Utilize two consecutive timing events for pulse generator configuration
anddata acquition
EEventsequence
EVENT‐nEvent preparation

NPP NMSaoSetting Gate delay
longout@OBJ=EVR1:Pul0, PROP=Delay

Gate-Delay
SCAN:Event

DlyGen0:Delay-SP
SCAN: Passive
NPP NMS¾ Multi-speed scanning- X, Y & U wire interact with beam at three distinct regions of whole span
- Slow speed scanning at regions of interactions results into better beam profile- Higher speed (Fast) at other regions results into optimum scan timeaoSetting Event code [EVENT‐(n+1)] forgenerating gate pulse
longout@OBJ=EVR1:Pul0, Func=$(F=Trig)

Gate-Pulse
SCAN: Event

EVENT‐(n+1)
Dbl pulse 1st, KLY HVtimeConclusion
9 New system is installed at Sector 5 of LINAC BT for testing
9The system is tested with PF and PF Study modes satisfactorily
9measurement became fast and precise after upgradation
9Data Acquisition system becomes simple and easy to takepulse-to-pulse beam data
9 The system will contribute significantly for beam tunningduring SuperKEKB commissioning and subsequent stages

Test results

KEKB:Pul0:EvtSCAN: Passive

Wire-scanner Record

Generate Gate pulse
DELAY

Read ADC & SCLR