Jan 30 2024

Action items from last time

• Carlos will develop a high-level timeline for the rest of the project.
• Now that the simulation models are working well, Max and Gabriel will optimize
  • the Pierce angle to give R28-like optics as a baseline and
  • the junction angle to allow for a larger lip radius, and less field enhancement. Carlos does not insist on the steep angle of R30-3, it can be a smooth transition.
• We will make two electrodes to have a spare; one can consider making two different shapes as a contingency plan. Carlos will ask Keith to join the meetings.
• Max will consolidate the set of field maps for apples/apples comparison in Alicia's injector model. Alicia will make a comparison between the updated R28, R30-3, and R30-4 models and work toward defining an acceptance band for phase-space parameters at the match point.
  

Updates and discussion

• Link to schedule Sharepoint
• Keith Harding reports it will take him ~ 3 days to modify the existing R30-3 Pierce front-end piece and make TWO new models per Max's design. Carlos told Keith the following parameters will change from the original R30-3 drawing:
  
  • Hole diameter
  • Pierce angle
  • Junction angle
  • Lip radius

Conclusions, path forward

• Deadline to define Pierce angle: Wednesday, February 7, 2024.Max, Alicia.
• Deadline to provide Keith Harding with the chosen models (TWO Pierce angle options): Friday, February 9, 2024.Max, Gabriel:
• February 13, 2024. Present before the B-Team meeting the strategy followed for arriving at the optimized Pierce angle. Max and Alicia.
• Enter here additional input from the meeting

Table of parameters (tentative)

/- 0.3?

/- 0.3

/- 2

/- 0.5

Parameter	Unit	Nominal value	Fabrication uncertainty	Simulation band	Comments
Hole inner radius	mm	6.4135
to edge of actual metal, as measured with caliper
Pierce angle	°	15	?
likely need to increase
Cone/sphere junction angle	°	62	?	30 -- 62	to be decided based on field-emission concerns; smooth transition = 26.971°
Cathode recess	mm	0.188	0.05	0.1	from Keith's drawing; error may be larger for old pucks
Cathode tilt	°	0
1
Laser spot size (RMS)	mm	0.5	0.1	0.2

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