Bunch-to-Bucket Transfer System

b2b logo.png

This work package was frozen from mid 2017 to mid 2019

The purpose of the Bunch-to-Bucket (B2B) transfer system is to transfer ion beams over the whole range of isotopes from one ring to another at GSI and FAIR. It employs the so-called phase-shift or frequency beating methods to achieve a phase match between bunch and bucket to better than 1 degree. The Bunch-to-Bucket (B2B) Transfer System is essential and indispensable for the FAIR accelerator chain. Without, no beam can be transferred from SIS18 to SIS100 and to follow-up machines. The B2B system is realized by the General Machine Timing (GMT) system and the Low-Level RF (LLRF) system. The B2B system is closely linked to other systems like kicker control and electronics as well as the machine protection system.


The aim of this web is to provide an overview on the Bunch-to-Bucket transfer system and its relationship to other systems. Moreover, it is the central point for documentation. Please note, that the B2B transfer system is still under development.



  • till January 2022
    • fix issues DONE
    • include option for SIS18 h=1 -> ESR h=1 DONE
    • install electronics for CRYRING injection and extraction kickers DONE
  • till 31 October 2021, integration into control system
    • FESA classes DONE
    • nomen DONE
    • LSA DONE
    • model DONE
  • Older Announcements


  • 29-Jun-2022:
    • esr-stacking.png
      Figure: stacking of beam in ESR (multiple injections from SIS18) with the bunch-2-bucket transfer system
  • 07-Jun-2022:
    • b2b esr-yr.png
  • 02-Jun-2022:
    • dedicated machine experiment SIS18 -> ESR
    • b2b- sis-esr.png
      Figure: true bunch-to-bucket transfer SIS (h=1) -> ESR (h=3); only one bucket gets filled
  • 01-Jun-2022:
    • more than four months of flawless operation ...
    • synchronization of ion bunch with PHELIX laser in cave HHT with 1 nanosecond precision
    • transfer from SIS18 to ESR as 'coasting beam'
    • fast extraction from ESR to HITRAP
    • transfer from ESR to CRYRING as 'coasting beam'
    • fast extraction from CRYRING
  • 22-Apr-2002:
    • first steps towards sub-ns precision for phase measurement (click)
  • 28-Jan-2022:
    • beam commissioning starts
    • first fast extraction from SIS18 in 2022 (using the b2b transfer system of course)
  • 17-21-Jan-2022, 'dry-run':
    • first operation of both CRYRING kickers with the b2b system
    • final model integration (CRYRING) and new LSA version deployed
    • timing of all extraction and injection kickers at GSI controlled by the b2b system
    • first successful operation of the b2b transfer in the entire facility demonstrated using coupled patterns of a chain SIS18 -> ESR -> CRYRING -> extraction!
    • b2b-sis-esr-yr.png
      Figure: operation of all kickers of all ring machines SIS18 -> ESR -> CRYRING
  • 12-Jan-2022:
    • installation of electronics at CRYRING injection and extraction kicker
  • 25-Nov-2021:
    • successful triggering of SIS18 and ESR kickers
    • demonstration of booster mode
    • b2b booster 2021-11-25.png
      Figure: booster mode on-line view (blue box) visualized by the B2B Monitor app. Shown are time of extraction (column 2), extraction machine, sequence ID and revolution frequency (columns 3,4,5), set-value of kicker trigger (column 6) and measured values of kicker trigger, delay of kicker electronics and delay of rising edge of kicker magnet probe signal (columns 7,8,9). Shown are also four other patterns executed in parallel; bunch-to-coasting beam SIS18->ESR (line 1), two patterns in ESR towards CRYRING beam-line and HITRAP (line 6,7) and a pattern in CRYRING with extraction (line 8). The ERROR at the CRYRING kicker indicates not yet installed componentes of the b2b system. The UNKNOWN values of the ESR kicker magnet probe delay require further commissioning.
  • 22-Nov-2021:
    • for the first time, the startup of the facility after a shutdown uses the bunch-to-bucket transfer system as the default transfer and extraction system
  • 18-Nov-2021:
    • phase measurement of DDS signals successfully tested at SIS18, ESR, CRYRING
  • 16-Nov-2021:
    • FESA classes for Central Bunch-2-bucket Unit (CBU) available and deployed to the PRO environment
    • two new analog signal processing units installed at SIS18 and ESR RF rooms
  • 10-Nov-2021:
    • CBU for CRYRING installed in RRF electronics room
    • 10 new fast and precise analog signal processing units delivered by the department of Experiment Electronics (EEL)
    • two units installed in SIS18 and ESR kicker rooms
Figure: Left: New comparators units delivered. Right: Unit mounted at a server of 1U height.
  • 15-Okt-2021:
    • integration system: 1st successfull integration of B2B in the full control system stack including ParamModi and LSA for SIS18 -> ESR
  • 24-Sep-2021:
    • FESA classes for Central Bunch-2-bucket Unit (CBU) available and deployed to the INT environment
  • 9-Sep-2021:
    • production system ported to timing release fallout 6.1.2
    • test setup based on fallout 6.1.2 installed at INT (transfers starting at SIS18 only)
    • DIM name server moved from office PC to ACC VM (rocky 8)
    • nomen for SIS18, ESR and CRYRING fixed
  • 13-Jul-2021:
    • first prototype of new signal conditioning unit tested with probe signal at SIS18 extraction kicker
  • 17-May-2021:
    • first bunch-to-bucket transfer SIS18 (h=2) -> ESR (h=1)
    • 2021-05-17 18-34-49 tcl1032 fct-ring trunc.png
Figure: Signal from FCT GE02DT1FP: Bunch from SIS18 captured in an ESR bucket. x-axis: bunch time [us] relative to h=1 (1.975 MHz), y-axis: time [ms] after acquisition start from bottom to top. The bunch is captured ~0.25 ms after acquisition start. Shown are data of ~ 3 ms after aquisition start. Data acqusition, processing and image are done by our colleagues from beam instrumentation.
  • 13-May-2021:
    • already two days of continous beam operation serving two distinct experiments in parallel
    • bunch-to-coasting-beam SIS18 -> ESR
    • fast extraction to cave HHT (experiment: synchronization of petawatt laser PHELIX with extracted ion bunch)
  • 11-May-2021:
    • first beam with the bunch-to-bucket system
    • 'bunch-to-coasting-beam' SIS18 -> ESR
    • bunch2coasting 2021-05-11.png
Figure: Bunches from the synchrotron SIS18 (magenta) are transferred into the storage ring ESR (orange, red)
  • 13-Apr-2021:
    • 'dry test' with SIS18 extraction kicker (just to confirm things work)
    • test with new Group DDS at SIS18
  • February 2021:
    • dry operation in parallel to beam time
    • see results
  • 15-Jan-2021: 'dry run'
    • bunch-2-bucket SIS18 -> ESR
    • comfortable command line interfaces for control and monitoring
    • see results
  • 05-Dec-2020: new page on B2B lite, setup, results
  • 27-Nov-2020: 'dry run'
    • phase matched extraction from SIS18
    • 'bunch to coasting dry beam ' transfer from SIS18 to ESR
    • see results
  • 26-Nov-2020: phase-matched extraction from ESR (with 'dry beam')
  • 23-Nov-2020: for the first time, the B2B system triggers the ESR kicker successfully!
  • 18-Nov-2020: for the first time, the B2B system triggers the SIS18 extraction kicker successfully!
  • 23-Dec-2019: proof-of-principle phase matching (using frequency beats) in RF supply room, see here
  • 12-Jun-2019: proof-of-principle phase matching (using frequency beats) on office table, see here


BunchBucket Web Utilities

-- DietrichBeck - 29 January 2022

  • stacking in ESR:
Topic attachments
I Attachment Action Size Date Who Comment
2021-05-17_18-34-49_tcl1032_fct-ring_trunc.pngpng 2021-05-17_18-34-49_tcl1032_fct-ring_trunc.png manage 59 K 21 May 2021 - 08:13 DietrichBeck SIS18 -> ESR, first bunch to bucket
b2b-_sis-esr.pngpng b2b-_sis-esr.png manage 61 K 08 Jun 2022 - 14:44 DietrichBeck bunch to bucket transfer sis->esr
b2b-sis-esr-yr.pngpng b2b-sis-esr-yr.png manage 52 K 26 Jan 2022 - 15:00 DietrichBeck SIS18 -> ESR -> YR ->Extraction
b2b_booster_2021-11-25.pngpng b2b_booster_2021-11-25.png manage 64 K 25 Nov 2021 - 19:16 DietrichBeck first booster mode operation using the b2b system
b2b_esr-yr.pngpng b2b_esr-yr.png manage 758 K 08 Jun 2022 - 14:48 DietrichBeck b2b ESR->YR
b2b_logo.pngpng b2b_logo.png manage 22 K 17 Oct 2020 - 11:03 DietrichBeck first unofficial logo with transparent background
bunch2coasting_2021-05-11.pngpng bunch2coasting_2021-05-11.png manage 301 K 11 May 2021 - 19:40 DietrichBeck SIS18 -> ESR, bunch to coasting beam
comparatorDelivered.JPGJPG comparatorDelivered.JPG manage 866 K 10 Nov 2021 - 10:56 DietrichBeck comparator delivery
esr-stacking.pngpng esr-stacking.png manage 66 K 01 Jul 2022 - 15:04 DietrichBeck stacking in ESR
Topic revision: r43 - 01 Jul 2022, DietrichBeck
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