Design and Integration meeting: 27 October 2025 11:00 BST

Zoom: ​https://ukri.zoom.us/j/99571436156

Agenda

• CDR.
• Simulations.
• AOB.

Notes

Present: WS MMC CW TJK KL JP JM
Absent: RR HO MP

• CDR
  • A few minor issues required discussion on the CDR:
    • Eqn 2.17 has a factor t in it which cannot be correct. Author unknown, JP to read references & correct.
    • Emittance not consistent in table 2.12, WS pointed out that MAD-X assumes constant emittance whereas BDSIM & GPT do not. JM to remove MAD-X emittance value from that table.
    • Font is small on a number of figures. WS can easily replot with larger fonts. JM & KL to send list of figures that need modifying.
    • WS to send JM the updated LhARA schematic diagram with updated caption.
    • WS to add dimensions to the diagram.
    • KL highlighted preferred use of mm & m, and to avoid cm. Text can be changed but modifying figures might be troublesome. Is context specific.
• Simulations
  • WS: no update due to time toward Imperial Lates last week.
  • TJK: plots shown on field leakage (see attached).
    • End leakage small & away from the cavity, not thought to be significant.
    • Field in the aperture/GFR does is larger. JP pointed out that the cores are at the edge of the aperture, not in it.
    • 250mm long cavity included but planned device is 200mm long
  • JP: Presented on chromatic effects in the Stage 1 arc. Slides will be attached.
    • Dispersion calculated to be small. Higher order dispersion is finite & thought may be contributing to the effects MP sees.
    • The impact on the beam size is small but this is noted to be recorded at the arc exit, not the end station (2m downstream).
• AOB
  • WS raised that the IPAC abstracts have opened. We agreed to submit a general LhARA update abstract.
  • JP recalculated RF cavity frequencies for protons & ions.
    • LhARA range should be 1.46 MHz to 6.51 MHz. Lower number comes from carbon ions at 4 MeV/u, upper from protons.
    • Stage 2 carbon ion energies will be limited to no lower than ~ 25 MeV/u. Radiobiological needs are unclear. A degrader may be needed for intermediate energies but fragmentation will be an issue.