Add particle species in Beam classes and update tracking methods #276
Conversation
cr-xu
changed the title
jank324
changed the title
|
I just realized that I still need to take the particle charges into account for the cavities/elements with electric fields. So this should probably wait until #278 is merged. |
…lement species tests
| :param voltage: Voltage of the cavity in volts. NOTE: This assumes the effective | ||
| voltage. If the particle does not have unit charge, the voltage needs to be | ||
| scaled properly. |
There was a problem hiding this comment.
This seems counterintuitive. Is this effect caused by us measuring energy in eV such that we cannot just set voltage = energy gain for non-unit charge particles?
This might especially lead to issues if we import lattices from external files. In that case the converter would have to know the intended particle species and adjust all voltages.
There was a problem hiding this comment.
Yes, I thought that confusing too at the beginning.
I went with this convention exactly due to the compatibility with the converters. Because Bmad also defines the voltage as the effective voltage for the ref. particle
There was a problem hiding this comment.
So @cr-xu you think we are fine as we are and won't run into problems when simulating other species?
There was a problem hiding this comment.
I think it's in the end a design choice... I see this convention (effective voltage rather than the physical one) as consistent with other normalized field strengths like
We can also just use the physical voltage,and just document/comment that extra caution is needed if they want to have non-unit charged particles.
There was a problem hiding this comment.
I have no opinion on this. I just want to know if this is okay to merge 😄
There was a problem hiding this comment.
@Hespe Actually now the voltage = total energy gain for non-unit charged particles. Setting the voltage to physical voltage would mean that total energy gain = voltage * q
There was a problem hiding this comment.
Yes, that is what I meant. For non-unit charged particles, we would have to take the charge into account to calculate the energy gain.
I think your argument that the cavity is particle independent is what I would have thought before. Otherwise you would have to know the particle you are going to simulate the correctly configure the Cavity element.
| :param voltage: Voltage of the cavity in volts. NOTE: This assumes the effective | ||
| voltage. If the particle does not have unit charge, the voltage needs to be | ||
| scaled properly. |
There was a problem hiding this comment.
Same as above. At least for me, it would be more intuitive if this is the physical voltage of the cavity and the effective voltage would be an implementation detail.
|
@Hespe I just committed the unfinished changes ... in case you want to continue them |
|
I have no idea why the tests failed in the morning. I was unable to reproduce the failure and now it suddenly all works. |
Description
Add the option to track with different particle species.
Changes:
Speciesclass that tracks the name, charge and mass information of particles. Some basic species are pre-defined, with the possibility to define custom mass-to-charge ratio particles.transfer_mapmethods and thecompute_relativistic_factorstake two arguments:[energy, particle_mass_eV]to account for different species.speciesproperty to keep track of the particle species.conda. Windows tests are run without Bmad because that latter is not available for Windows.Motivation and Context
This was requested in #231 and #263.
Types of changes
Checklist
flake8(required).pytesttests pass (required).pyteston a machine with a CUDA GPU and made sure all tests pass (required).Note: We are using a maximum length of 88 characters per line.