Coherent Tune Measurement Design Review

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Coherent Tune MeasurementDesign Review

• Michelle Wilinski
• March 26, 2003

2
Outline

• Action Items from July 2002 Review
• Overview
• High Voltage Pulser
• Tune DAQ
• Process Variables
• Acceptance Criteria
• Summary

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July Review Action Items Committee Findings

• Tune can be measured using turn-by-turn mode
  included in BPM system driving beam with BIG
  kicker can augment signal
• Agree, system designed using such
• Numerous measurement methods were described, but
  not implementation details
• To follow

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Coherent Tune Overview

• Hardware used pulser, kicker, BPM associated
  DAQ/processing electronics
• Initial processing executed in BPM PCI card
• Tune calculations performed in a LabVIEW program
• Measured one or more times during accumulation
  cycle for 1-10 turns
• AP required measurement accuracy /- 0.001
• AP required measurement resolution /- 0.0005
• Measurement requires averaging

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Coherent Tune Block Diagram
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Coherent Tune BIG Kicker

• Voltage /- 7KV Aperture 21cm
• Length 4.5m (3 striplines of 1.5m each)
• q 0.6mrad b 15m
• Amplitude (p-p) 2cm
• Dp/p .01 x 8
• Chromatic Tune spread x Dp/p .08
• Decoherence time about 12 turns

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Pulser Block Diagram
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High Voltage Pulser Specifications

• Pulser will need to drive 250ft (76m) of 7/8
  Heliax to kicker with length (including
  interconnects) of 4.7m to 50W load
• HV power supplies 7kV, -7kV
• Switch voltage rating 14kV
• Output polarity changed on turn-by-turn basis
• Trigger level 30V
• Rise Fall Times 30ns
• Pulse length 190ns
• Switch between output modes, preferably at
  60Hz
• 1MHz burst of 1-10 pulses repeated at 60Hz (Tune)
• 1MHz burst of 60-100 pulses repeated at 60Hz
  (BIG)
• Switch between kicking on horizontal or vertical
  planes
• Average 1kW delivered to load when kicking
  vertical, dominant mode
• Average 50W delivered to load when kicking
  horizontal
• No short circuit/collision protection - effects
  of short

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Short/Open/Collision Effect on Pulser

• An short or open will cause a reflection of
  pulse, 14kV across closed switch
• A switch pair collision will cause virtual
  ground between pair

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HV Pulser Status

• Pulser unit will be located in High Voltage Room
• Option 1 -Purchase pulser as one integrated unit
  from vendor
• Diversified Technologies, Inc. (MA)
• Cost 250k (not including integration/testing at
  BNL/SNS)
• 8 switches _at_ 20k/ea. 160k 2 power supplies
  10k
• Controls/integration/test 40k NRE (20ns
  RT/FT) 40k
• Lead time 6-8 months
• unit would fill one complete rack
• Directed Energy, Inc. (CO)
• No existing product, will not custom design for
  small procurement
• Option 2 - Purchase items separately and
  construct at BNL
• Switch vendors
• Power supply vendors
• Lambda/EMI 10kV -10kV supplies, 6,680/ea.
  (13,360 for two), 8-10 week lead time
• Universal Voltronics waiting for response
• Introduces manpower labor costs for design
  construction

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DTI Switch Module
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Tune DAQ BPM PCI Card

SSRAM
SIGNAL DIGITIZERS
PCI BUS

ALTERA FPGA
ADC Clock.
Amplifiers and Signal Conditioning
PUE
T 0 TRIGGER
Control I/O
Event Link
EL RTDL Receivers
RTDL
Power Supply
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Tune DAQ Processing

• Tune will be using the BPM PCI interface card for
  data acquisition
• Tune system control done by existing Altera FPGA
  on card
• Pulser trigger additional output from FPGA
• Since Tune BIG hardware and processing
  applications will be in different PCs, control
  logic (in hardware and/or software) to prevent
  both systems from triggering the pulser at once
  is necessary
• After initial processing on PCI card, LabVIEW
  will carry out remaining processing
• Utilize LabVIEW template written by W. Blokland,
  bpm.dll, program written for BNLs Booster Tune
  Meter ? build on existing applications for ease
  of future modifications

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Booster Tune Meter (BTM) LabVIEW front panel

• Contains programmatic controls, graphs for
  displaying raw data FFT tune results on Main
  front panel tab
• Other front panel tabs (not shown) contain
  scope info, returned parameters from processing
  algorithm, error messages, help files

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BTM Controls
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BTM Controls/Display
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Process Variables System Inputs

• Kick polarity
• Determines output polarity of kick (/- or -/)
• Plane to kick
• Determines plane to kick (horizontal or vertical)
• Kick trigger
• When to trigger the pulser for kick(s)
• BPM PCI process type
• Determines processing type on PCI card (baseband
  or RF processing)
• Other applicable BPM PCI process variables
• Power supply on/off
• Remote control for the power supply
• RTDL
• Event Link

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Process Variables - System Outputs

• Kick mode
• Determines mode of pulser operation (Tune or BIG)
  
• Tune measurement
• Calculated result from LabVIEW
• Tune spread
• Calculated result from LabVIEW
• Power supply remote/local
• Readback to determine mode
• Power supply on/off
• Readback to determine if supply is on/off
• Capacitor bank voltage
• Readback to assure power supply is charged as
  expected

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Acceptance Criteria

• Meets applicable BPM acceptance criteria
• Meets AP specifications
• Test on resonator
• Accuracy /- 0.001
• Resolution /- 0.0005
• Pulser meets requirements
• Output /- 7kV
• Polarity changed turn-by-turn
• Select plane to kick
• 1MHz burst of 1-10 pulses
• Vertical System Integration to EPICS screen
  demonstrated

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Cable Plan

• Cabling from BPM to be as specified for BPM
  system
• 50 ohm phase-matched and stabilized heliax (1/4
  or 3/8 inch)
• Terminated in bulkhead N connectors with N to
  SMA adapters. Short, flexible, 50 ohm coaxial
  cables terminated in SMA connectors will be used
  to make the connections from the Heliax to the
  electronics and PUEs.
• Cabling from pulser direct to kicker will be 7/8
  heliax terminated in L5PN series high-power
  connectors. DTI recommends 75 ohm cable (standard
  Andrew item)
• kicker design is being revisited to look at
  matching this impedance.

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Summary

• One pulser unit kicker to be shared among
  Coherent Tune and Beam in Gap systems
• Pulser option to be selected - confident of
  vendor capability but hesitant because of cost
• Using BPM and PCI card for data acquisition only
  additional hardware is pulser trigger.
• Put experience with Tune systems at BNL to work

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extras
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Schedule - Tune
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DEI /-6kV pulser

• Requires TTL gate input, HV DC power supplies
• Output pulse width frequency controlled by gate
  trigger voltage controlled by power supply
  amplitude
• 8 units - 11,475ea. (91,800) 10 units -
  10,950 (109,500)

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Lambda/ALE HV PS 402 Series

• AC Input 208VAC
• Avg. Charging Rate 4000J/s at rated voltage
  output
• Peak Charging Rate 5000J/s at rated voltage
  output
• Voltage 10kV, -10kV (2 units)
• Pulse-to-pulse repeatability /-2 to 1kHz
• Protection against open circuit, short circuit,
  overload, arcs
• 19 rack mountable
• Similar to supply used for ARTUS (RHIC tune
  meter) uses 5kV version