BPM Upgrade Projects Status

1
BPM Upgrade ProjectsStatus Technical Update

• Bob Webber
• DOE Review of Tevatron Operations
• March 2005

2
Recent and Active BPM Projects

• Recycler Ring
• Completed and operational since early 2004
• NuMI Beam Line
• Completed and operational since first NuMI
  extracted beam
• This system reported meaningful beam position
  data on first pulse !!!
• Tevatron Ring (1.4.5.4) (9/2/03 5/17/05)
  (1081K labor, 1764K ms)
• Installed and operational for routine proton
  measurements in 25 of the ring functioning
  compatibly with remaining old systems
• Completion of installation scheduled for end of
  May 2005
• Antiproton Transfer Lines (1.3.6.5.2) (3/26/04
  7/25/05) (91K labor, 284K ms) (details in
  Elvin Harms Rapid Transfer Talk earlier this
  breakout)
• In final design stage, manpower assigned, 80
  procurements done
• Will employ NuMI/Recycler software and Tevatron
  EchoTek boards
• Completion expected by August 05
• Main Injector Ring (1.1.3.2) (1/3/05 6/1/06)
  (324K labor, 900K ms)
• Requirements being reviewed
• Awaits manpower currently devoted to Tevatron and
  Transfer Line projects
• All systems are built around a common, commercial
  digital receiver board (Echotek)

3
Tev BPM - General Status

• Joint Computing and Accelerator Division project,
  CD has provided 80 of total reported project
  effort
• Essentially all hardware is in hand, including
  spares
• Considerable planning and care allow adiabatic
  installation without adversely impacting Tevatron
  operations
• It is a big deal to seamlessly replace a large
  operational system without disrupting Collider
  operation and luminousity production
• 7 of 27 systems are installed and routinely
  operational for proton measurements (functional
  replacement for old systems)
• Antiproton position measurements have been
  demonstrated but not yet routinely operational
• Installation pace is presently limited equally
  by
• Opportunity -- we dont install during a Collider
  store
• Debugging - operational problems must be solved
  as they are discovered

4
TeV BPM - Software

• 85 of required VME front-end software
  functionality has been implemented and debugged
• Data is packaged, either in VME front-end or in
  ACNET BPMLIB library code, to look like data
  from the old BPM system so as to minimize
  modifications to legacy console applications
• Software switch permits transparent operation
  with mixture of old and new BPM systems in field
• Critical legacy console applications are working
  with new BPM data after little or no modification
• Some new applications are being developed to take
  advantage of the systems new capabilities
• SDA is being updated to use the new BPM data as
  each new crate is installed

5
TeV BPM - Colored Pictures!

• A3 House Installation BPM
  Integrity Check

6
TeV BPM 36 Bunch Closed Orbit Resolution Upper
Limits
20 minutes of closed orbit data for A3 BPMs 400
microns full vertical scale all plots
Histograms of same data and RMS variation from
the mean
7
TeV BPM 36 Bunch Closed Orbit Resolution
Correlation plot of closed orbit data from
two BPMs on opposite sides of ring estimate
resolution to be 5 microns
8
Tev BPM Single Proton Bunch TBT Measurements
TBT resolution is better than 50 microns RMS
9
TeV BPM - Antiproton Measurement Plan A

• Establish cross-talk (imperfect pickup
  directionality) coefficients a, b, c and d and
  compute corrected antiproton signals according
  to
• Now working to establish unique coefficients for
  each BPM and automate operational maintenance of
  time varying values
• There is a Plan B

10
TeV BPM Antiproton Measurements
Proton sum signal
Proton position
Ramp
Proton loading
Pbar position
Pbar sum signal
Pbar loading
Pbar sum signal during proton loading
(ideally zero)
11
TeV BPM - Whats Left

• Solve currently known bugs
• Intermittent first-turn and injection
  turn-by-turn measurements (phase/timing problem)
• Complete hardware installation
• Implement and test additional required
  functionality
• Robustness of Pbar measurements
• Safe mode (timing robust first turn
  measurements)
• Calibration-scaling-offset database
• Produce as-built drawings and documentation
• MOU -gt operations
• Project closeout

12
Transfer Line BPM

• First system required to observe both 53MHz and
  2.5MHz beam structures
• Major impact on design and required dynamic range
  of analog circuitry upstream of digital receiver
  boards
• Precursor to MI BPM system with similar
  requirement
• Operational scenarios are complicated due to
  different beam structures through beam lines at
  different times
• Recycler/NuMI front-end software that is suited
  mode switching and cycle dependent data buffers
  will be used
• Design of analog circuit is in final prototype
  stage
• All major procurements except analog boards are
  complete
• VME front-end software is ready and waiting
• Prototype/development system now installed at F23
• Schedule calls for completion mid to late summer
  2005 integration will be subject to operational
  constraints

13
Main Injector BPM Project

• Main Injector BPM project will follow on the
  heels of the Tevatron and Transfer Line BPMs
• Scope
• Replace signal processing electronics and
  front-end data acquisition systems for 208 beam
  position monitors located around the Main
  Injector and in six buildings
• Objectives
• Eliminate obsolete Multibus II hardware and ACNET
  communications protocol
• Accommodate measurement of beam in 2.5MHz RF
  buckets
• Provide improved measurement resolution
• Beams Document 471, dated February 2003,
  specifies system requirements and is now under
  review by Main Injector Department

14
Main Injector BPM - Similarities to Tevatron BPM

• General system design and implementation
• Beam information to be obtained and types of
  measurements, i.e. first turn, closed orbit, and
  turn-by-turn
• Anticipated hardware, except more complicated
  analog circuitry upstream of digitizer
• Scope of DAQ, on-line, and off-line software,
  although different in detail

15
Main Injector BPM - Differences from Tev -- All
in the Details

• Main Injector operating cycles are more varied in
  type than in Tevatron and dynamically interwoven
  in time
• Both 2.5MHz and 53MHz signal frequencies must be
  processed (in different Nyquist bands)
• Measurement data for multiple operating cycle
  types is to be stored separately in parallel
  front-end data buffers
• Both protons and antiprotons must be measured,
  but
• Do not circulate simultaneously
• Pickups are not directional
• no separate p/pbar cables
• protons and pbars require different fine timing
• Measurement of user selectable segment (batch) of
  the circulating beam is required

16
Main Injector BPM - Anticipated Implementation

• Analog front-end electronics will leverage
  heavily off Transfer Line BPM project (common
  requirement to deal with 2.5MHz and 53MHz signal
  frequencies)
• VME and VXWORKS front-end DAQ systems as other
  new systems
• Tevatron style EchoTek digital receiver boards
• Tevatron style digitizer clock and timing boards
• Front-end software probably dependent on what
  group implements the system (different in detail
  from both Tevatron and Recycler)

17
Main Injector BPM - How Project Likely Plays Out

• Little dedicated effort invested up to now other
  than clarification and refinement of requirements
  
• MI department occupied with NuMI commissioning
• BPM people occupied with the other new BPM
  systems
• Analog front-end design will flow from Transfer
  Line project
• People who provided engineering, software, and
  technical support for NuMI BPM will focus on
  Transfer Line project through May 05
• Software support from Tevatron project might
  become available in June 05
• Commodity procurements can begin any time
  (EchoTek boards already procured and in hand)
• A development system initially with either
  Tevatron or Recycler software should be installed
  in MI by June 2005
• Computing Division will likely play a major role
  in the project

18
BPM Projects - Summary

• We are mid-stream in the effort to re-build all
  major BPM systems in the accelerator complex
  except Linac and Booster
• Results from completed Recycler and NuMI system
  and partially installed Tevatron system show
  excellent performance and operational credibility
  and utility
• Considerable effort remains to
• Complete Tevatron system
• Overcome analog signal challenges for Transfer
  Lines and Main Injector
• Meet the diverse and dynamic functional
  requirements demanded in Main Injector

19
BACKUP SLIDES

• 1577 B3 resolutions
• 1571 coupling
• 1581 pbars
• 1752 for Robs most recent very good talk

20
Antiproton Measurements

• Present ratio of proton to antiproton intensities
  combined with directivity of stripline pick-up
  produces residual proton signals at the
  antiproton port about 50 the amplitude of
  antiproton signals
• When antiproton intensities increase they will
  begin to contaminate the proton signals also
• We opt to not pursue p/pbar separation by precise
  timing

Pbar bunch signal
Typical signal from pbar end of BPM for present
bunch intensities
Undesired Proton bunch signal
80 nsec/tic
21
Antiproton Plan B

• Separate p/pbar signals with relaxed timing
  requiring precision and maintenance of 50 nsec
  rather than 5 nsec
• Observe only isolated proton or antiproton
  bunches at ends of 12-bunch trains
• No pbar bunches observable One pbar
  bunch observable
• Five bunches observable Two
  bunches observable

22
Coverage of Ring in Antiproton Plan B

• Locations with at least one clear pbar bunch (at
  least 400 nsec from nearest proton bunch) at
  various times in cycle
• x axis is feet around ring from B0, each point is
  BPM location
• y axis is clearance gt21 is clear

23
HA15 and VA14 P/Pbar Positions Plan BChanging
Separators
Position Scales 2mm/box
Horizontal Pbar
Vertical Pbar
Vertical Proton
Horizontal Proton
24
Horizontal A15 Helix Change and Pbar Loss Plan B
25
Block Diagram Cartoon of Signal Path
Proton Inside
Eight Channel VME Digital Receiver
VME CPU
attenuator
53MHz BPF
Proton Outside
attenuator
53MHz BPF
Pbar Inside
attenuator
53MHz BPF
Pbar Outside

• Note that proton and pbar signal paths from same
  half of BPM are directly connected together by
  the stripline --- reflections from one will feed
  directly into the signal of the other

attenuator
53MHz BPF
Diagnostic and Calibrate Signals
ACNET
26
Main Injector BPM - Possible Roles for Computing
Division

• Total effort level would be between that provided
  for Recycler and Tevatron BPM Projects Less
  engineering design effort than in Tevatron
  project
• Administrative project management
• Analog circuit board layout and fabrication based
  on AD designs
• Support for procurement, incoming component
  inspections and testing, production testing,
  equipment tracking, etc.
• Supply Tevatron BPM style timing boards
• DAQ, on-line, and off-line software components
  after successful completion of Tevatron system
• Installation manpower
• To serve all these roles, CD effort estimated as
  on the scale of 60 FTE months
• Learning curve (AD language, machine operational
  issues, ACNET) has already been largely traveled
  by CD personnel on Tevatron project
• Details will be different

27
BPM Accuracy/Resolution Specs
This is Table 2 from Requirements document. Table
gives the most stringent requirements on the
system for certain types of operation these
requirements are relaxed. Note resolutions are
stated as 3 sigma.
28
Demonstrated Beam Measurements

• Recycler-type BPM front-end is set up for
  development and tests in TeV House A1
• Connects to both Proton and Pbar signals of one
  horizontal BPM and one vertical BPM
• Interfaced to ACNET with small subset of ultimate
  required functionality
• Closed orbit and turn-by-turn measurement
  performance have been demonstrated
• In use to assess narrowband frequency domain
  p/pbar signal de-convolution
• Will soon demonstrate wide time separation of
  Protons and Pbars (utilize isolated bunches at
  the ends of the otherwise over-lapping 12-bunch
  trains) 50 rather than 5 nsec timing

29
Proton Positions in Load of Store 3172 Old vs
New
Old rms error 140 um for uncoalesced beam, 70
um for coalesced beam, and 0.6 mm step between
the two
New rms error 25 um for uncoalesced beam, lt9
um for coalesced beam, no step between the two
30
Closed Orbit Resolution During Proton Loading

• Green Vertical Position _at_ 100 microns/div
  showing 10 micron resolution and orbit changes
  due to leakage fields in ramping injection
  Lambertson magnet
• Red Beam Intensity showing proton bunches
  loading
• Yellow Time in Supercycle

31
Upper Limit of Closed Orbit Resolution
Two one-hour periods of 1 KHz bandwidth proton
position measurement data, 17 hours apart, in
store 3148. (data-logged at 1 Hz) 50 microns /
vertical division
Demonstrates upper limit resolution of 9 microns
rms in 1 Khz (any real beam motion not excluded)
to meet spec of 7 micron 1 sigma in 10Hz
32
Injection Turn-By-Turn --- Un-coalesced Protons
Vertical A14 Horizontal A15
vertical tune horizontal tune
vertical axis units are millimeters in all
plots
33
Turn-by-Turn Long After Injection Single
Coalesced Bunch
Horizontal transverse motion due to persistent
synchrotron oscillation
vertical axis units are millimeters in all plots
Vertical A14 Horizontal A15
34
Upper Limits on TBT Resolution --- Vertical A14
Standard deviation of raw data is 34 microns
If remove betatron and synchrotron motion by
zeroing 17 frequency line amplitudes around
betatron frequencies and one at synchrotron
frequency, leaving untouched 494 of the original
512 frequencies, TBT resolution is found to be 15
microns
35
Same Coalesced Proton Bunch Given Big Vertical
Kick
vertical tune horizontal tune
vertical tune
Vertical A14 Horizontal A15
36
Antiproton Plan A
P Upper Scope
Pbar Upper Scope
In
Refl
In
Refl
Linear System
P Upper In
5
6
Pbar Upper In
1
4
3
P Lower In
2
7
8
In
Refl
In
Refl
P Lower Scope
Pbar Lower Scope

• Model BPM as an 8-port network at processing
  frequency
• Measure network transfer functions with beam,
  e.g. ratio of proton signal on pbar end to proton
  signal on proton end
• Measure signals then correct according to
  pre-determined transfer function before computing
  positions
• Measurements in process to determine achievable
  accuracy