Parameters of elasticScatteringLifetime

[Bingfeng]

Hello Michael:
I'm currently learning to use elasticScatteringLifetime, and I have a few questions about its parameters.

usage: elasticScatteringLifetime -aperture <daFile> -name <string>(10Percentile) -twiss <twissFile> -output <filename> [-sPeriodic <value>27.61] [-pressure nTorr(2)] {-gasMix {APS|N2} | -customGas <gas>:<frac>,...}
Known gases for custom gas list are H2 H2O CH4 CO CO2 N2

In the official example, the -name parameter is set to Clipped.
I assume this means that xClipped and yClipped from .aper file are used for the calculation, is it true?
If I want to use x and y instead, what should I input for -name?
Also, what are the other available options for -name?
Additionally, could you please explain what the default value 10Percentile represents?

2. In bremsstrahlungLifetime, there is also a parameter -name. In the official example, it is set as

Code: Select all

-name ""

Could you please clarify what this means?

Thank you very much.
Best regards,
Bingfeng

[michael_borland]

Bingfeng,

These two scripts are no longer supported. I recommend using the elastic_scattering and inelastic_scattering commands in elegant, along with the programs elasticScatteringAnalysis and inelasticScatteringAnalysis.

In the official example, the -name parameter is set to Clipped.
I assume this means that xClipped and yClipped from .aper file are used for the calculation, is it true?
If I want to use x and y instead, what should I input for -name?
Also, what are the other available options for -name?
Additionally, could you please explain what the default value 10Percentile represents?

Yes, that's what "-name Clipped" means. The 10Percentile suffix could come from a set of DA simulations where we find the 10th-percentile x and y contours. If you want to use just x and y, try

Code: Select all

-name ""

The meaning is similar for the bremsstrahlungLifetime script. By default, it will look for deltaNegative$name in the momentum aperture file, so

Code: Select all

-name ""

means to use "deltaNegative". Other options, such as -name Min or -name Max would use deltaNegativeMin or deltaNegativeMax.

--Michael

[Bingfeng]

Hello Michael:
Thank you very much for your explanation.
I tried the elastic_scattering command in elegant, but encountered a new problem.
It seems that all the particles are lost, even though they are within the DA found by find_aperture command.
I tried different ranges for theta, but regardless of how small theta_min is, particles can not survive,
and the lifetime decreases as theta_min is reduced.
Thank you in advance for your help.

[michael_borland]

Bingfeng,

I tried this with the parTrack.lte file that's included in the examples/PAR/elasticScatteringTracking folder, and didn't see an issue. Did you use a different .lte file? Which version of the code are you using?

--Michael

[Bingfeng]

Dear Michael,
I used the same example, and the files were uploaded as run1.zip.
I changed the theta_min as 0.00000000000013, still no particles can survive.
The version of elegant is 2023.4.
Here is the output of code displayed on the screen.

Best regards,
Bingfeng

[michael_borland]

Bingfeng,

You didn't include the .lte file in the run1.zip file. Can you post the file you are using?

--Michael

[michael_borland]

Bingfeng,

I recalled just now that there was a bug introduced into elastic scattering in 2023.4. I think it was ok the prior version, so you might try that that.

The bug has been fixed but we haven't released it. That should happen in early December.

--Michael

[Bingfeng]

Hi Michael,
Thank you very much. I'll try another version.
Best regards,
Bingfeng

[Bingfeng]

Dear Michael,

I tried using elegant 2021.4 and it worked. Thank you very much.
And there is one more small suggestion about this command:
There are some elements of zero length in my lattice file.
By default, this command tracks particles at all elements, which results in some locations being tracked multiple times.
This leads to repeated loss records in elasticScatteringAnalysis, ultimately causing incorrect results.

For experienced users, it may be obvious that each scattering location should be tracked only once.
But it did take me some time to identify this issue.
It might be helpful, especially for newer users, if a note could be added to the user manual clarifying that each scattering location should only be tracked once.
(I also noticed a similar situation occurs with inelastic tracking.)
Thank you very much again for your invaluable work.
Best regards,
Bingfeng

[michael_borland]

Bingfeng,

Thanks for the suggestion. I'll add that to the manual.

--Michael