f Beam Line Tuners Vic Scarpine Instrumentation DoE Review Oct 28-31, 2002

f October 28-31, 2002DoE Review - Instrumentation - BLT2 Introduction Primary function of a Beam Line Tuner (BLT) is to measure turn-by-turn transverse beam positions during transfers between machines at injection to improve closing –Required in Tevatron, Main injector and Recycler –Can measure betatron oscillations, fractional tune, coupling, phase, synchrotron oscillations, chromaticities, etc Focus has been on betatron measurements for improved closing –Feed-forward correction system BLT is a key component for reducing transverse emittances and increase luminosity

f October 28-31, 2002DoE Review - Instrumentation - BLT3 Basic BLT System

f October 28-31, 2002DoE Review - Instrumentation - BLT4 Striplines and Fanout TeV Stripline Parameters: –~ 30 dB directionality –1 meter long (< 1/4 ) –D = 83 mm –0.65 dB/mm Sensitivity MI and Recycler Stripline Parameters: –Unidirectional – 1.4 meter long (1/4 ) –D = 110 mm –0.50 dB/mm Sensitivity

f October 28-31, 2002DoE Review - Instrumentation - BLT5 Operational Systems

f October 28-31, 2002DoE Review - Instrumentation - BLT6 Tevatron BLT For transfers from Main Injector to Tevatron Requirements (in order of importance – V. Lebedev) : 1.Measure initial injection oscillations for every proton and pbar bunch –first 50 turns with <50  m resolution 2.Measure tunes, coupling and chromaticities for every bunch –> ~1000 turns 3.Monitor beam position before quench –~ last 500 turns saving beam waveforms Beam formats: –Pbar: Four 53 MHz bunches separated by 392 ns at 150 GeV –Protons: Single 53 MHz bunch at 150 GeV

f October 28-31, 2002DoE Review - Instrumentation - BLT7 Tevatron Scope BLT In Operations Use Tektronix TDS7104 as fast waveform digitizer –2.5 GSample/sec/channel –Segmented memory –Embedded Celeron PC Samples proton bunch or four pbar bunches per transfer Signal processing analysis on waveform in Scope PC Decimate data to single position per bunch –Pbars – 64 turns –Protons – 256 turns

f October 28-31, 2002DoE Review - Instrumentation - BLT8 Tevatron Scope BLT Results First Pbar TransferSixth Pbar Transfer pbar bunches per transfer; 64 turns per bunch; closing on second bunch

f October 28-31, 2002DoE Review - Instrumentation - BLT9 Tevatron Scope BLT Position calculation: X = K * (A – B) / (A + B) Resolution: ~ 140  m Calculate oscillation phase and amplitude from first 16 turns Correct injection magnets for next transfer for amplitudes > 0.25 mm Betatron phase and amplitude for all 36 pbar bunches

f October 28-31, 2002DoE Review - Instrumentation - BLT10 Tevatron Scope BLT Status Tektronix scope system in operations –Limited by slow internal data transfer ~20 seconds for 64 turns for pbars Improvements –New scopes have increased memory – two scopes just arrived Allows for ~800 turns for pbars, ~2000 turns for protons –Upgrade scope software to improve internal data transfer Increase acquisition speed by ~ x10 –Modifying position algorithm to improve resolution ~ 30 to 50  m –Integrate improvements over next few weeks

f October 28-31, 2002DoE Review - Instrumentation - BLT11 Main Injector BLT Requirements: –Measure position for first 1024 turns for all pbar bunches at injection from either Accumulator or Recycler “Hot” pbars from Tevatron in future Beam Formats: 1.Accumulator to Main Injector – Four batches of 7 to 13 bunches of 53 MHz at 8 GeV 2.Recycler to Main Injector – Four bunches at 2.5 MHz at 8 GeV 3.Tevatron to Main Injector – 36 single bunches at 53 MHz at 150 GeV (Hot pbars)

f October 28-31, 2002DoE Review - Instrumentation - BLT12 Main Injector BLT in Operations Using older AM/PM modules (see J. Crisp talk on BPMs) –Originally designed for eighty- four 53 MHz bunches –Lower efficiency for 7 bunches –Less resolution –Won’t work for 2.5 MHz Digitize at 53 MHz LabView controls acquisition and analysis Output 1024 vertical and horizontal positions plus fractional tunes and betatron phase and amplitude to ACNET

f October 28-31, 2002DoE Review - Instrumentation - BLT13 Main Injector BLT Results Phase and amplitude for 9 transfers Correct for amplitude > 0.5 mm Positions and tunes for first 1024 turns Correct on second bunch in transfer

f October 28-31, 2002DoE Review - Instrumentation - BLT14 Main Injector BLT Status Present system based on old AM/PM modules –Adequate for closing but needs updated to more responsive system System can not measure 2.5 MHz beam from Recycler Plan: Installing Digital Receiver system for 2.5 MHz beam –Installation occurring now Need to replace present 53 MHz system –Decision to be made on choice of Digital Receiver system or Scope system

f October 28-31, 2002DoE Review - Instrumentation - BLT15 Recycler BLT Requirements: –Measure position for first 1024 turns for all bunches at injection from Main Injector to Recycler Waveforms: –Four 2.5 MHz pbar bunches at 8 GeV System based on Digital Receiver technology –Uses Echotek digital receiver Just into Operations

f October 28-31, 2002DoE Review - Instrumentation - BLT16 Digital Receiver Options Hardware Option (see J. Crisp talk on BPMs) –8 channel EchoTek card (VME64) –65 MHz ADC, 14 bits –Hardware digital mixer, filters and decimation Software Option –8 channel Struck digitizer (VXI) –100 MHz ADC, 12 bits –Software digital mixer –Correlation algorithm to measure channel amplitude

f October 28-31, 2002DoE Review - Instrumentation - BLT17 Recycler BLT Positions and tunes for 1024 turns

f October 28-31, 2002DoE Review - Instrumentation - BLT18 Recycler BLT Status System in operations for about one week Closing routinely to < 0.3 mm No changes planned to system

f October 28-31, 2002DoE Review - Instrumentation - BLT19 Systems in Development

f October 28-31, 2002DoE Review - Instrumentation - BLT20 TeV Scope BLT Phase Detector Measures phase of four pbar bunches relative to RF using Tektronix 7104 scope Measurement point every 18 turns –64 turns is really 1100 turns Phase error of ~11 degrees (~0.55 ns) –Resolution ~ 1 degree (50 ps) 1234

f October 28-31, 2002DoE Review - Instrumentation - BLT21 Tevatron Digital Receiver BLT Software version of Digital Receiver system for pbars 30 MHz LP to ring single 53 MHz bunch –Ring for ~100 ns Digitize at 100 MHz Correlate with normalized response function Generate position and bunch phase for >1024 turns

f October 28-31, 2002DoE Review - Instrumentation - BLT22 TeV Digital Receiver BLT Horizontal TunesVertical Tunes

f October 28-31, 2002DoE Review - Instrumentation - BLT23 TeV Digital Receiver BLT Vertical Position vs TurnHorizontal Position vs Turn

f October 28-31, 2002DoE Review - Instrumentation - BLT24 TeV Digital Receiver BLT Comparison of position data to theory (courtesy of V. Lebedev) + Horizontal Position, --- Difference from fitPosition, --- Difference from fit Synchrotron factored out

f October 28-31, 2002DoE Review - Instrumentation - BLT25 Tevatron Waveform Movie Proton injection Vertical Stripline into fast scope Red = A-B Blue = A+B 1 to 2000 turns by ns sampling Negative Vertical Chromaticity Longitudinal dampers off

f October 28-31, 2002DoE Review - Instrumentation - BLT26 Head-Tail Measurements (courtesy of P. Ivanov) Developing of the head-tail instability with dipole longitudinal configuration Developing of the head-tail instability with monopole longitudinal configuration

f October 28-31, 2002DoE Review - Instrumentation - BLT27 Chromaticity Measurement by the Head-Tail Monitor (courtesy of P. Ivanov)

f October 28-31, 2002DoE Review - Instrumentation - BLT28 Summary Tevatron, Main Injector 53MHz and Recycler 2.5 MHz operational for injection closing Main Injector 2.5 MHz being installed Upgrades progressing for Tevatron and Main Injector 53 MHz systems Multi-systems need to be evaluated and decision made on priorities and how many systems to support –Advantages and disadvantages of each system –Need to guard against over design

f October 28-31, 2002DoE Review - Instrumentation - BLT29 Cast of Characters Instrumentation: Jim Crisp, Brian Fellenz, Eugene Lorman, Warren Schappert Pbar Source: Dave McGinnis Tevatron: Petr Ivanov, Valeri Lebedev Advise and Consent: Church, Pasquinelli, Pordes and others …with apologies to anyone forgotten