H- source characterisation #1

Tuesday 23 May 2023, 16:00 → 17:00 Europe/Zurich

CERN

Discussion on LNS/LNI H-/pbar characterisation tool

https://cern.zoom.us/j/69902558269?pwd=MVgyQmJrVlFsTldmWUlKbCtyT2svQT09

- **Yann (ABT)**: analysis notebook to perform quadscan analysis from previously taken images: 
   - take images from screen at ELENA injection
       - data taken previously by scanning the last two quads of LNI line
   - perform a Gaussian fit of transverse profiles
   - perform Twiss reconstruction based on matrices computed from MAD-X model

- **Lajos (AD/ELENA)**: tracking code/simulations
   - tracking of beamline from source to ELENA ring
       - includes an accurate description of source quads and ion switch
   - found that focusing/defocusing quads might be inverted
   - adding aperture and additional details ongoing

- **Vittorio (AWAKE)**:  tomographic reconstruction of phase space
   - classes developed in python and available on GIT
   - package to generalise tomography on "any beamline" being developed 
   - data taking is NOT included for the time being
       - only offline analysis for the time being with single quad being scanned (at least from )

- **Avni (CLEAR)**: generic quadscan tool in MATLAB
   - it creates beamline description (matrices) from MAD-X
   - allows taking data "live" 
   - it allows using as many quads as desired
   - has a convenient graphical interface
   - plans to convert it to Python at some point (not soon)

- **Davide (CTF3)**: CTF3 experience
   - during CTF3 time, MATLAB tool used for quadscan, tomography, as well as phase-space painting, from data taking to data analysis in a single "script"
   - Code available on [git](https://gitlab.cern.ch/ELENA/quadscan/-/tree/master/MATLAB), but probably quite messy. 
   - 
- **Alessandra (LINACs)**: LINACs experience
   - old series of tools for emittance reconstruction in principle available, if interested
       - possible to take into account space charge effects
       - based on linear matrix reconstruction
       - particle tracking code debugged for several years
       - mainly post-processing analysis tools
   - **interest**: measure emittance and alpha/beta parameters needed for ELENA operation, i.e. to know if a standard CERN-based H- source could be used in the long term future in ELENA

### Agreed short-term plan:
- **Lajos**: tracking simulation tool from source to ring
   - study a "wide" beam and look for bottlenecks...
- **Vittorio**: continue on quadscan-tomography-like tool development in Python
   - help/collaboration from Avni and Yann, as needed.
   - will try to apply it to available data already taken
- **Lajos**: will follow up on different development and share a folder with all tracking/analysis etc...
 

16:00 → 16:10 CTF3 experience

Speaker: Davide Gamba (CERN)

constantBeamSize_7July2016.pdf

16:10 → 16:20 CLEAR Experience

Speaker: Avni Aksoy (Ankara University Institute of Accelerator Technologies (TR))

quad_scan_clear.pdf

16:20 → 16:30 LNE experience

Speaker: Yann Dutheil (CERN)

16:30 → 16:40 AWAKE Experience

Speaker: Vittorio Bencini (John Adams Institute for Accelerator Science (GB))