Undulator Cavity BPM Design and Status

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Undulator Cavity BPM Design and Status
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X-Band Cavity BPM Overview

• Cavity BPM system design
• Current status for prototype testing
• Planning for first article and production

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LTU and Undulator BPM System Specification
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In-Tunnel Electronics Block Diagram
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X-Band Cavity BPM Design

• SLAC selective coupling design utilized to reduce
  monopole leakage
• Solid Copper Body
• WR-75 waveguide output
• Waveguide transition brazed to body

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Prototype Cavity BPM Specification
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Dipole Cavity Design

• Beam pipe radius 5 mm
• Cavity radius 14.937 mm
• Cavity gap 3 mm
• Distance beam axis to bottom of wg 9.5 mm
• Waveguide 19.05 x 3 mm

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Monopole Cavity Design

• Beam pipe radius 5 mm
• Cavity radius 11.738 mm
• Cavity gap 2 mm
• Coupling Slot 4 x 2 mm
• Shortest distance from cavity opening to bottom
  of waveguide1.734 mm
• Waveguide 19.05 x 3 mm

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Cold Test Prototype

• Non-vacuum cold test prototype
• Removable end caps
• Accelerates test fixture development and cold
  test procedures

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Vacuum Window Prototype Cold Test

• Utilized standard CPI WR-75 window
• Silver plated Kovar/Glass vacuum seal
• Window cost 100 vs. 218 for Kaman coax feed
  thru
• Insertion Loss lt 0.2 dB
• Return loss -20dB

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Waveguide Transitions Prototype Cold Test

• Transitions E plane from 3 mm to 9.53 mm
  (standard WR-75)
• Waveguide transition brazed to body
• Insertion Loss lt 0.2 dB
• Return loss -20dB

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Before Soldering Transitions and Windows
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X-Band Cavity BPM Cold Test

• Waveguide and windows soldered together
• Unit is vacuum tight except for removable end
  caps
• First data looks encouraging

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Monopole and Dipole Wideband Sweep
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Dipole Cavity Design
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Monopole Cavity Design
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In-Tunnel Receiver Block Diagram
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Prototype Receiver Specification
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Miteq X-Band Low Noise Receiver

• Existing product line
• WR 75 Waveguide Interface
• Low Noise Figure (2.7 dB)
• Budgetary price for (3 channels) 6500.00

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Prototype X-Band Low Noise Receivers

• Conversion gain 27.5 dB
• Over 60 dB dynamic range
• Noise Figure 2.5 dB
• IF bandwidth 40-80 MHZ
• Ready for ITS Installation

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Prototype Receiver Data
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APS Test Objectives

• Develop a cavity BPM that meets system
  requirements and can be manufactured economically
• Develop simulation model that correlates to
  prototype data
• Transition from prototyping to production

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BPM System Test Approach

• Phase I
• Injector Test Stand ITS
• Install single X-Band Cavity and modified
  off-the-shelf down converter receiver
• Mount BPM on Piezo two-axis translation stage

• Phase II
• Bypass line or LEUTL test with PC gun
• Install three X-Band Cavities BPMs
• Bypass line test with PC gun to start June 06

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Injector Test Stand ITS Beam Parameters

• Charge- 1 nC single-bunch
• Bunch length- 3 - 4 ps FWHM for ps laser
• Spot size on final screen at 5.5 MeV 0.75 mm
  rms, ps laser

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Phase I Data Acquisition Design Approach

• Instrument three channel down converters with
  Struck SIS-3301-105 ADCs 14-bit
• Single VME board will provide the data
  acquisition for 8 channels
• Epics driver complete
• Digitize horizontal, vertical position and
  Intensity 0 to 1 volt range
• Fit Data to decaying exponential at 50 MHz

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Phase I Testing Objectives

• Test prototype Cavity BPM, down converter, and
  data acquisition
• Generate preliminary compliance table to
  specification
• Gain operational experience to determine if
  translation stage is useful, what are optimum
  operating parameters

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Phase I Schedule Milestones

• Design and develop prototype Cavity BPM
• Prototype non vacuum
• Jan 06
• Build single Cavity BPM
• Feb 06
• Cold Test
• Feb 06
• Install cavity BPM into ITS and Test
• Feb 06

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Phase II Schedule Milestones

• Refine design and develop First Article Cavity
  BPM and support hardware
• March 06
• Build 3 Cavity BPMs
• March 06
• Cold Test
• May 06
• Install 3 cavity BPMs into APS PAR/Booster bypass
  line or LEUTL and Test
• June 06

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Phase II Testing Objectives

• First Article Prototypes evaluated
• Test three BPM separated by fixed distance to
  determine single-shot
• Complete test matrix

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LTU and Undulator Planning

• Receiver and LO housed in shielded enclosure
  below girder 20 watt power dissipation maximum
• Presently BPM output on wall side
• BPM output flexible waveguide section allows
  movement for alignment

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BPM Mounting

• BPM connects directly to the girder.
• Mechanical adjustment stage used for alignment
• BPM and Quad can be adjusted into position
  independent of one another

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Undulator Planning
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Production Phase

• Production of 2 BPMs for LTU 04/07
• Production of 6 BPMs for undulator 04/07
• Production of 8 BPMs for undulator 06/07
• Production of 3 BPMs for LTU 06/07
• Production of 8 BPMs for undulator 08/07
• Production of 3 BPMs for LTU 08/07
• Production of 12 BPMs for undulator 10/07
• Spares 12/07

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Summary

• X-Band Cavity BPM development ongoing
• Brass body prototype (non-vacuum)
• ITS prototype (vacuum)
• Receiver Prototype ready for ITS installation
• Parts are assembled and tested
• Waveguide components received
• Data Acquisition
• SLAC providing constructive communications and
  collaboration