elegant 25.3.2 released

[michael_borland]

We are pleased to announce the release of elegant version 25.3.2. This version has a number of bug fixes, as well as numerous new features, which are detailed in the updated manual.

One noteworthy new feature is significantly improved support for multi-bunch collective effect simulation. In addition to long-range, multi-turn resonant wakes, elegant now supports long-range, multi-turn non-resonant wakes (e.g., resistive wall). At the same time, short-range wakes can be applied within individual bunches of a multi-bunch beam. The manual contains more details, including a section on preparing the beam file.

Another noteworthy addition is two new scripts, bremsstrahlungLifetime and elasticScatteringLifetime, for computing the gas scattering lifetime from the aperture determined by tracking. By performing explicit integrals over position, these scripts should give more reliable results than methods based on average values of lattice functions and apertures.

--Michael

[marlibgin]

Hi Michael and all
I would be very grateful if I could have more details on the use of elasticScatteringLifetime,
I understand one can use the DA calculated in several parts of the ring. Is the pressure an average or rather one
can put the values measured at different position in the ring? Any working example for an easy start. e.g how to
define the partial pressures etc?

Thanks Marco

[michael_borland]

Marco,

See the attached files for an example of using a constant pressure distribution and an s-dependent distribution. I'll add these to the official examples file as well.

--Michael

[marlibgin]

Thanks very much !

[marlibgin]

Thanks very much for this example (zip file) that you sent me.
I have expanded the compressed file, obtaining a directory named gasScatteringLifetime,
I use "Notebook" as a mini-guide to the use of the package. So I first ran with "run 16" over 16 cores to produce the DA and LMA files,
this appeared to be flawless. After I tried to run
elasticScatteringLifetime -aperture daTrack.aper -name Clipped -twiss daTrack.twi -output daTrack.esl -sPeriodic 30.667 -pressure 1 -customGas H2:0.65,H2O:0.02,CH4:0.07,CO:0.22,CO2:0.04

this produces an error, it seems the customGas specifications are not recognized
Unknown option(s) given to APSStrictParseArguments "-customGas H2:0.65,H2O:0.02,CH4:0.07,CO:0.22,CO2:0.04"
usage: elasticScatteringLifetime -aperture <daFile> -name <string>(10Percentile) -twiss <twissFile> -output <filename> [-sPeriodic <value>27.61] [-pressure nTorr(2)]
while executing
"if {[APSStrictParseArguments {aperture name twiss output sPeriodic pressure}] || ![string length $aperture] || ![string length $twiss] || ![string len..."
(file "/dls_sw/prod/tools/RHEL6-x86_64/elegant/28-1-0/prefix/bin/elasticScatteringLifetime" line 25)

if I remove the customGas part the script run.


Another thing is that I cannot see the specification of pressures as a function of "s", the examples seem to be done for a constant value, but I might misunderstand the use of the script itself

[marlibgin]

Can you be more specific on the use of sPeriodic and pressure, e.g. if I put -sPeriodc 30 -pressure 1 I guess I specifiy a pressure of 1 nTorr at position 30, or at every 30 m? My problem consists in specifying the pressures recorded in 24 cells with 6 different probes per cell. Priodicity is sometime broken (no symmetry in the machine) so it woul be great to have a table of s values (pressure points) and corresponding pressures, but still I cannot grab how to actually implement it, Thanks

[soliday]

What version of elegant do you have installed? This thread is from 3 years ago and elasticScatteringLifetime did not have any customGas option at that time. The current release of elegant (32.0.0) includes a newer version of elasticScatteringLifetime that has this option.

[michael_borland]

Marco,

If you want to give s-dependent pressure data, you need to use elasticScatteringLifetimeDetailed, not elasticScatteringLifetime. The latter assumes constant pressure around the ring.

--Michael

[marlibgin]

Hi, I have tried to use
elasticScatteringLifetimeDetailed as suggested, and created myself a file of pressures, something like this
SDDS1
&description text="pressure as a function of s", contents="whatever", &end
&column name=s, symbol=s, units=m, type=double, &end
&column name=Pressure, symbol=P, units=nTorr, type=double, &end
&data mode=ascii, &end
! page number 1
4
10.00e+00 0.000000000000000e+00
20.00e+00 1.307792127736331e-03
30.00e+00 2.688447851062043e-03
40.00e+00 4.249351077562158e-03


but I was told off this way:
no known gas species (N2,CO2,H2O,CO,H2,CH4) identified in list of columns: s,Pressure

So I am trying to introduce gas species but I haven't got a clue. ElasticGasLifetimeDetailed
does not seem to need the gas composition as an external parameter,

usage: elasticScatteringLifetimeDetailed -aperture <filename> [-name <string>] -twiss <filename> -pressure <filename> -output <filename> [-sPeriodic meters(27.6)]

yet it should be passed from within the pressure list file, but I need to know a structure/format for it

Thanks in advance
Marco

[michael_borland]

Marco,

As shown in the example in the the examples file (on the web, also attached for your convenience), the pressure file should have columns for the partial pressure of individual gasses, e.g., H2O, H2, N2, etc., as listed in the error message you quoted. The reason for this approach is that the partial pressure of different gases varies with position in different ways.

If you only have an overall pressure, then you can try

• Rename the Pressure column in your file to reflect the dominant species. E.g., if H2O is dominant species, try renaming "Pressure" to "H2O".
• Or, split the Pressure up into columns that reflect your estimated gas makeup.

Note that in either case, the pressures should be in nT.

--Michael