340 likes | 490 Views
LCLS Cavity BPM Status and Testing. In-Tunnel Electronics Block Diagram. Cavity BPM Development. R&D phase completed Testing phase II completed Entering production phase. 3-BPM Test First Article. Cold Test 1st Generation. ITS Test 2nd Generation. X-Band Cavity BPM Development.
E N D
Cavity BPM Development • R&D phase completed • Testing phase II completed • Entering production phase 3-BPM Test First Article Cold Test 1st Generation ITS Test 2nd Generation
X-Band Cavity BPM Development • Five X-Band Cavity BPM built and tested • Two qualified vendors for machined parts • Brazing procedure optimized to preserve tune • Tuning and testing procedures generated
Port 1 Port 4 Port 2 Y-Port Port 3 Monopole mode X-Port Vertical dipole mode BPM Simulations • Cavity BPMs simulated in Microwave Studio, HFSS and Mafia • Test data indicates good agreement between simulated model and measured BPMs
Prototype BPMs for 3-BPM test • 4 BPMs built and tested to support 3-BPM testing • Design and technology mature
New End Cap • End-cap design mechanically strengthen • Can retune once flange is installed • Tuning pins are protected against accidental mistuning • New end-cap designed and tested • Vacuum flange test prototype pending
Cavity BPM Production Status • Cavity BPM machining contracts placed with parts expected 11/27/07 • Two vendors will provide a single machined First Article BPM for evaluation • Vacuum window first lot delivery 11/12/07 • Vendor for brazing BPM pending contract award
Receiver Electronics Development • R&D phase complete • Test fixtures developed • Entering production phase
Receiver Development • X-Band down-converter developed from existing Miteq product • Modified to meet LCLS requirements • 3 channel receiver with common LO • 4 first article packaged receivers delivered and presently being tested
X-Band Receiver Chassis • Line Replaceable Unit (LRU) design • Local status interface indicators for power, operational mode, gain range, self-test • Integral heat sink and EMI chassis design
Receiver Production Status • Drawings updated and released • Specifications generated on receiver, local oscillation and filters • Vendor selection same as 3-BPM first article • Presently quoting production quantities
Comprehensive BPM Test Program • Non-Vacuum Single BPM cold test unit complete 04/06 • (Phase I) test in APS Injector Test Stand complete 09/06 • (Phase II) 3-BPM test in APS LEUTL • Completed test matrix to prove compliance to specification • Production phase started
3-BPM Test at APS LEUTL • 2-axis translation stage installed and tested provide sub-micron controllable horizontal and vertical motion • Multiple experiments conducted to verify operation
Test Parameters • Beam Energy – 400 MeV • Beam Charge/pulse – 0.2 to 0.5 nC • Beam Repetition Rate – 6 Hz • Beam Pulse Width – 2 ps FWTM (uncompressed) • Diagnostics: • LEUTL current monitor • Flags upstream and downstream of test setup • Quad doublet focusing/steering upstream of test setup
Single-Shot Resolution Test Procedure • Use calibration to get a list of horizontal and vertical positions for each BPM • Can do Model Independent Analysis (MIA) or Least Squares Analysis (LSA) • Predict position at middle bpm (BPM 2) using horizontal and vertical positions at BPMs 1 and 3. • Histogram the residuals for BPM 2 and standard deviation is the resolution
Histogram residuals for BPM 2 Courtesy Nick Sereno
3-BPM Test Apparent Y resolution sY = 270 nm Courtesy Steve Smith
3-BPM Test Apparent X resolution sx = 360 nm Courtesy Steve Smith
1 Hour Stability Measurement Courtesy Nick Sereno
LCLS Three-BPM Test Conclusions • Resolution spec met • Long term drift spec for 1 hour spec met • Gain stability spec met • 1 hour temperature stability spec met • 24 hour temperature stability spec met electronics with simulated beam
Undulator System Layout Beam X-band receiver LRU
Deliverables per BPM • 1 Cavity BPM assembly • 1 X-band receiver • 3 Waveguides and 2 loads with assembly hardware • 1 Receiver mounting hardware assembly • 1 BPM mounting stage • Bellows and finger inserts
Production Milestones • Production of 2 BPMs for LTU 01/08 • Production of 6 BPMs for undulator 02/08 • Production of 10 BPMs for undulator 03/08 • Production of 11 BPMs for undulator 04/08 • Production of 7 BPMs for undulator 05/08 • Spares 4 BPMs 05/08 • 40 sets of Electronics 07/08
Summary • X-Band Cavity BPM • Development phase complete • Production procurement in place • First machined production units expected in November • Receiver Electronics • 4 First article prototypes assembled and tested with good results • 3-BPM testing prototypes incorporate receiver, local oscillator and filter first article packaging • Production procurement ongoing • Test Qualification • Successful collaborative effort testing and qualifying BPM system • Qualified system with the same ADC (PAD) as SLAC LINAC BPM upgrade to minimize risk of integration
Production Risks • New End Cap design • New tuning scheme • Window plating problem • Unexpected integration problem • Unexpected vendor problem