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synchronous phase difference

Posted: Tue 16 Dec 2025 14:19
by Lennert.dk
Hi Didier,

I have a couple of questions regarding the synchronous phase:

1. I've noticed that there is a tiny difference between the set input synchronous phase (-45°) and the actual synchronous phase of the first cavity (44°).
This is not immediately a problem, but I'm wondering where the difference comes from.

2. Secondly, I've noticed that the second cavity in my period always has a slightly higher synchronous phase,e.g. -44° for cav1 and -44.3° for cav2. Why is that? which rule in your algorithm causes this? I'd expect that following the const. longitudinal/phase acceptance would result in a continuous decreasing sync. phase...

3. When I apply the equation for const. longitudinal acceptance myself I get slightly different sync. phases for subsequent cavities, e.g. for the first cavity in the second period, I find -42.8°, while GLW finds -43.3°. (Proton energy at the LINAC entrance = 16.6 MeV, and at the entrance of period2 = 17.2 MeV).

If needed, I can send you the project files in a private message.

Cheers,

Lennert

Re: synchronous phase difference

Posted: Thu 18 Dec 2025 14:05
by Didier
Dear Lennert,

Points 1 and 2 were definitely caused by a bug that I recently introduced by mistake and have now fixed. You can upgrade your software. This will probably fix point 3 as well, but you'll have to let me know.

Regards,

Didier