= LhARA radiobiology; meeting: 05Mar26; 14:00 GMT =

**ZOOM:** https://imperial-ac-uk.zoom.us/j/98220889714?pwd=SM90vOF7BKSXoU3mD9q7OwBQo4IVB3.1 

Attended: PH, KL, JB, MH, CW, ND, AFr

== Meeting Notes == 

0. Short Recap of In-Person

1. BioPrep
- Updates:
 - No Update but things discussed:
  - Short-term plan is probably use Marie's lab as it has the microscope, etc., but there is a preference to shift to doing everything at SCAPA.
  - Monitoring for the incubator, Robbie can do remote monitoring for the incubator using a Raspberry Pi, etc. 
  - Would be useful to find the hard limit that cells can survive vertically

Something has been a problem with burning mirrors that was there before with Ross

2. Simulations
- Updates:
 - Josie presented the latest BO results on finding the optimal beamline
  - [raw-attachment:PoPLaR_update_05March26.pdf Slides]
  - Ran several optimisations, all using a laser-driven energy spectrum:
   - 2 Quad (Varying positions for transmission)
   - 2 Quad (Varying positions for uniformity)
   - 2 Quad and 4 Dipoles (Varying positions and varying dipole length and strength as a group for transmission)
   - Any Quad Combination (Varying number and position of quads for transmission
  - Generally, best results appear to have the beamline elements as close as possible to the source and have the cells as close as possible too.
  - To get a more useful optimisation need to specify a beam energy 
   - Talk to Robbie about the energy spectra graph and its stability
   - Talk to the bio team about what energies we should be avoiding (Simulate LET for a range of energies in the cells?)
 - BELLA Paper
  - Deliver a 2.0 ± 0.4Gy beam with a lateral dose variation of 7% and centred on 8MeV
  - The average uncertainty on their overall dose delivered was 12%
  - Beamline consists of a laser-driven source, quad doublet, kapton scattering foil, dipole magnet, mouse ear, RCF and scintillator
   - Laser-driven source ran at 7J over 60fs, so lower power than SCAPA, and onto a 13um Kapton target (same as SCAPA).
    - The laser was 50um from its optimal focal length to achieve a better shot-to-shot variation. This helped reduce it from 17% to 5%
   - Quads are a 250 T/m with 5mm bore radius and 67T/m with 15mm bore radius
   - Kapton scattering foil is 25um and is placed there to smooth the beam and remove heavier ions
   - Dipole magnet of 264mT and 95mm in length removes x-rays, gamma-rays and electrons
   - 25um Kapton exit window
   - The mouse ear is ~300um so it allows 8MeV protons to pass through and reach RCF and a scintillator passed that
   - Other diagnostics are integrating current transformers
    - Would be worth investigating in combination with sci-fi arrays for instantaneous dose measurements
  - They delivered a shot every 20s, so they investigated instantaneous FLASH rather than overall FLASH
  - Josie will simulate the beam to get a better understanding
   - LhARA knows someone at BELLA, so she is the person to ask if any information is missing

3. SCAPA Beamline
- Updates:
 - No update, but things discussed:
  - Is there something that can stop the lens element from burning? Maybe something that Ross used to use?

4. In-Beam Diagnostic
- Updates:
 - No update, but things discussed:
 - Jeff mentioned putting cells on RCF
  - https://pmc.ncbi.nlm.nih.gov/articles/PMC12340475/#:~:text=5.,delivered%20to%20the%20cell%20substrate. 

5. Other beamlines
- Updates:
 - Josie is sourcing the information to simulate ELI
  - Nick suggested emailing since they are usually happy enough to share information
 - There is a space to apply for beamtime at ELI 
  - Deadline is 22nd Apr

6. DoNM 
 - 19th Mar 14:00

7. AoB 


=== Summary of actions required ===

In-Beam Diagnostics
- **RW, CD**: Study correlation between laser diagnostics and mean dose
- **CD, TP**: Refine evaluations of LET in the cells with the RCF in front
- **CD**: Predict the cell dish dose from the RCF in front of it
- **PH**: Investigate how to get the light out of the vacuum chamber
- Investigate how a phosphor sheet could be incorporated into the design
- Acquire a glass sheet

Bio Next Steps
- **EM**: Write up a biology plan
 - Decide whether to use Marie's lab and whether to stick with HeLa
- **EM, MB, JP, RA**: Meet to finalise details
- **Unassigned**: Obtain an inverted microscope
- **Unassigned**: Run controls to examine how long the cells can survive vertically

Improve the spatial variation
- Decide the energy we should be optimising for
 - **RW**: Examine energy spectra variation
 - Find LET for different energies in the cell dish

Other Beamlines
- **JMcG**: Simulate BELLA
- **JMcG**: Talk to ELI people and simulate ELI
- Build a bid towards ELI

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