Cavity cuts lines

Summary

When a cavity is in the beam line it cuts the beam in longitudinal direction.

Steps to reproduce

Run the Injector 2 with cavities in.

What is the current bug behavior?

injector_2

added Bug OPAL-cycl + 1 deleted label

Do you see the same behaviour in the PSI Ring model?

No, in my single bunch Ring model, I did not see this behaviour.

I do not see this behaviour in OPAL-1.6.0

It doesn't occur in OPAL-1.6.1 and OPAL-1.6.2, but in OPAL-2.0.2.

I think, I found the bug. The variable DistOld should be in units of mm according to line 3206. However, in the function ParallelCyclotronTracker::checkGapCross it is computed in units of m. Therefore missing a factor 1000. I have to run some checks but including the factor removes these lines in configuration space. The problem is that the RFCavity still uses units of mm and ParallelCyclotronTracker is partially changed to units of m.

I also think the calculation of c_mmtns is wrong. Instead of

constexpr double c_mmtns = Physics::c * 1.0e-6; // m/s --> mm/ns

it should be

constexpr double c_mmtns = Physics::c * 1.0e6; // m/s --> mm/ns

created merge request !170 (merged) to address this issue

mentioned in merge request !170 (merged)

assigned to @frey_m

No, sorry. The c_mmtns is fine.

added 1 deleted label

With the fix, we obtain an extraction energy of 72.017 MeV for the Injector 2 (verified with single particle tracking)

injector_2_orbit.pdf

mentioned in merge request !172 (merged)

closed