Acceleration and deceleration

[EsraaKh]

Dear Michael,

I am optimizing the acceleration and deceleration process in an Energy Recovery Linac (ERL) using the RFCA element. The setup involves two 9-cell cavities: the first cavity operates with a phase of 45°, and the second cavity has a reversed-phase relative to the first.
The goal is to optimize the phases and voltages to achieve acceleration to 55 MeV and deceleration to 5 MeV.
I have been using the PHASE_REFERENCE parameter with various positive values, but so far, I have been unable to meet the desired targets. I have attached the relevant file for your reference.
Could you please guide me on how to resolve this issue?

[michael_borland]

I think you forgot the attachment.

--Michael

[EsraaKh]

Halo Michael

I attached the lattice and ran files to this post, I am still having a problem with acc/dec. the second acceleration is not completed to 55 MeV but around 35 MeV. I am doing optimization for the phase to be on the crest and the voltage and the problem is on the definition of the phase, so according to "SRS" model, the phase is pi/4 but also depends on the initial conditions, in this case, I have in the 2nd acc a deceleration so I change the phase to be 90 deg, as you can see in the plot I don't have the correct value. Also, the N_KICKS do not change the calculations, and I have a high value in the optimization function. Could you please help me with this issue?

[michael_borland]

Is this a racetrack design with independent linacs in both straight sections?

In your lattice file, it seems that the basic sequence is

Code: Select all

FirstLinac,SecondLinac,RecircArc1,FirstLinac,SecondLinac,RecircArc2, ...

I would expect something like

Code: Select all

FirstLinac,RecircArc1,SecondLinac,RecircArc2,FirstLinac,RecircArc3,...

so that the first and second linac have different functions.

--Michael