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Undulator Cavity BPM Status and Plans. X-Band Cavity BPM Development. Removable end cap prototype built and tested Cold test fixtures and measurement procedures generated ITS prototype unit received and presently being cold tested. Vacuum Window Prototype. Utilized standard CPI WR-75 window
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X-Band Cavity BPM Development • Removable end cap prototype built and tested • Cold test fixtures and measurement procedures generated • ITS prototype unit received and presently being cold tested
Vacuum Window Prototype • Utilized standard CPI WR-75 window • Silver plated Kovar/Glass vacuum seal • Window cost $100 vs. $ 218 for Kaman coax feed thru • Insertion Loss < 0.2 dB • Return loss -20dB
Prototypes Bolted end caps Brazed end caps
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
Monopole and Dipole Wideband Sweep Bolted End Caps Monopole Cavity Dipole Cavity antenna offset 2 mm
Dipole Wideband Sweep Brazed End Caps Antenna Offset 0.5 mm Antenna Centered (null)
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 waveguide=1.734 mm • Waveguide= 19.05 x 3 mm
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
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
Lab Data Acquisition Development 100 MHz sampling • Cavity BPM and electronics tested using an impulse generator • Optimization algorithm used to find best fit • Comparing fits from 5 GHz sampling scope 5 GHz sampling scope
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 BPM System Test Approach
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
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
Phase I Schedule Milestones • Design and develop prototype Cavity BPM • Prototype non vacuum Cavity BPM complete • Build single Cavity BPM • Delivered April 17, 2006 • Cold Test and install cavity BPM into ITS • April 06 • ITS Testing • May 06
Phase II Schedule Milestones • Refine design and develop First Article Cavity BPM and support hardware • June 06 • Build 3 Cavity BPMs • August 06 • Cold Test • September 06 • Install 3 cavity BPMs into APS PAR/Booster bypass line or LEUTL and Test • October 06
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
Design Enhancements for Manufacturing • Tuning Pins to tweak frequency and isolation • Strengthen end caps to reduce mechanical deflection • Increase braze surface on end cap to body interface
Production Phase • Production of 2 BPMs for LTU 04/07 • Production of 4 BPMs for undulator 04/07 • Production of 10 BPMs for undulator 06/07 • Production of 10 BPMs for undulator 08/07 • Production of 10 BPMs for undulator 10/07 • Spares 12/07
Summary • X-Band Cavity BPM development ongoing • Bolt-together prototype (non-vacuum) complete • ITS prototype (vacuum) preparing for ITS test • Receiver Prototype ready for ITS installation • Parts are assembled and tested • Waveguide components received • Data Acquisition and Test • SLAC providing constructive communications and collaboration