1. Undulator Cavity BPM System Status
May 14, 2019
Undulator Cavity BPM System Status

2. In-Tunnel Electronics Block Diagram

3. 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

4. Prototype BPMs for 3-BPM test
4 BPMs built and tested to support 3-BPM testing
Design and technology mature

5. BPM Simulations
Cavity BPMs simulated in Microwave Studio, HFSS and Mafia
Test data indicates good agreement between simulated model and measured BPMs
Port 1
Port 4
Port 2
Port 3
X-Port
Y-Port
Vertical dipole mode
Monopole mode

6. Prototype BPMs for 3-BPM test

7. Cavity Cold Test Critical tuning experience gained
Test fixtures designed and built for tuning before brazing
Post braze tuning minimized by pre-tuning and controlling braze process
Good correlation between cold test and beam test

8. Tuning Pins Tuning pins improve performance and production yield
Tuning pins prototyped and tested
Tuning pin simulations verify measurements

9. Cold Test After Brazing and Tuning
Serial #
Dipole
Freq. (GHz)
Loaded Q
Monopole
Design Goal
11.384
3550
3695
R/0
3310
3437
001
11.374
3250
11.382
3372
002
11.376
3500
11.383
3436
003
11.377
3371
11.400
3200

10. Brazing Problems Tuning Pins difficult to braze.
New braze fixtures designed and built
End Cap design being evaluated
Problems with window leaks
Window plating suspected

11. Cavity BPM Development
R&D phase of near completion
Testing phase II expected completed by end of July
Entering production phase

12. 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

13. X-Band Receiver System Features
Input RF Power Surge Limiters
Input DC power regulation
High/Low gain feature (28/0dB) to extend dynamic range
Integrated self-test
Multi-mode operation with phase locked LO to control system or free-run mode

14. X-Band Receiver Packaging Design
Receiver enclosure 12.5 wide by 15 deep by 2.5 thick (inches) with integral heat sink
Houses input filters local oscillator and down-converter
3-WR75 Inputs, 3-type “N” outputs, LO ref. input Type “N”, power and control cable

15. 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

16. Dynamic Range Testing

17. Frequency Response Sweep

18. Receiver Electronics Development
R&D phase of near completion
Testing phase II expected completed by end of July
Test fixtures developed
Entering production phase

19. BPM Testing 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
Complete test matrix to prove compliance to specification
Testing phase II expected completed by end of July

20. LEUTL 3-BPM Test PC gun installed and LEUTL tunnel commissioned
PC gun beam 325 MeV (400 pC) to dump
33 Hor. and 23 Vert. micron normalized emittance
Compressed beam 1 ps bunch length

21. In-Tunnel Progress
2-axis translation stage installed and tested provide sub-micron controllable horizontal and vertical motion
Multiple experiments presently conducted to verify operation
Testing ongoing

22. Electronics Stability Testing

23. Single BPM Test

24. 3-BPM Test Apparent X resolution 8 microns rms
Courtesy Steve Smith

25. Undulator System Layout
Beam
X-band receiver LRU

26. Production Phase
Production of 2 BPMs for LTU 11/07
Production of 6 BPMs for undulator 11/07
Production of 10 BPMs for undulator 01/08
Production of 11 BPMs for undulator 02/08
Production of 7 BPMs for undulator 03/08
Spares 4 BPMs 03/08

27. Summary X-Band Cavity BPM Development Nearly Complete
4 Cavity BPM built and tested
Machining and braze critical tasks identified
BPM phase ll testing expected complete July 07
Production procurement ongoing
Receiver Prototype Development Nearly Complete
First 4 prototypes assembled and tested with good results
3-BPM testing prototypes incorporate receiver, local oscillator and filter first article packaging
Test Qualification
Collaborating with SLAC to test and qualify
Qualifying system with the same ADC (PAD) as SLAC LINAC BPM upgrade
Testing is ongoing at this time with promising results
Entering Production phase