atphysics#

Accelerator physics

Modules

CollectiveEffects	Collective Effects
LinearOptics	Linear beam dynamics
LongitudinalDynamics	Longitudinal beam dynamics
NonLinearDynamics	Non-linear beam dynamics
Orbit	Closed orbit search
ParameterSummaryFunctions	Summaries of lattice parameters
Radiation	Functions dealing with synchrotron radiation
TouschekPiwinski	Touschek liftime and apertures
TuneAndChromaticity	Tune and chromaticity
nafflib	NAFF frequency analysis

Classes

PhysConstant

Physical constants

Functions

`atavedata()`	Average of optical functions on selected elements
`findrespm()`	computes the change in the closed orbit due to parameter perturbations
`findspos()`	returns longitudinal positions of accelerator lattice elements.

class PhysConstant#: Physical constants

Automatically generated from https://physics.nist.gov/cuu/Constants/Table/allascii.txt

The values of the constants provided at this site are recommended for international use

by CODATA and are the latest available.

Termed the “2022 CODATA recommended values,” they are generally recognized worldwide

for use in all fields of science and technology.

The values became available on 20 May 2024 and replaced the 2018 CODATA set.

They are based on all of the data available through 31 December 2022.

The 2022 adjustment was carried out under the auspices of the CODATA Task Group

on Fundamental Constants.

atavedata(ring, dpp, refpts)#: Average of optical functions on selected elements

[lindata,avebeta,avemu,avedisp,tunes,chroms]=atavedata(ring,dpp,refpts)

LINDATA : Identical to ATLINOPT output

AVEBEA : Average Beta functions

AVEMU : Average phase advance

AVEDISP : Average dispersion

TUNES : Vector of tunes

CHROMS : Vector of chromaticites

[lindata,avebeta,avemu,avedisp,tunes,chroms]=atavedata(ring,dpp,refpts,orbitin)

does not search for closed orbit. instead ORBITIN is used

findrespm(ring, obsindex, perturbindex, pvalue, 'field', m, n, orbitfunction, args)#: computes the change in the closed orbit due to parameter perturbations

Two calling syntax options

1. findrespm(ring, obsindex, perturbindex, pvalue, ‘field’, m, n, orbitfunction, args)

2. !!! not implemented yet findrespm(ring, obsindex, perturbgroup, pvalue, orbitfunction, args)

RING - ring lattice

OBSINDEX - indexes of elements where the orbit is observed (at the entrance)

PERTURBINDEX - Integer indexes of elements whose parameters are perturbed

used with syntax 1 only.

PERTURBGROUP - cell array of AT paramgroups. See ATPARAMGROUP

used with syntax 2 only

PVALUE - amount of peturbation

(Numeric array or scalar if all perturbations are the same magnitude)

FIELD,M,N are only use with syntax 1.

FIELD - field name of the parameter to perturb (string)

M,N - index in the matrix, if the field is a matrix

For example to perturb the quadrupole field in a

multipole element

FIELD = ‘PolynomB’, M = 1, N = 2

ORBITFUNCTION - specifies which of the FINDORBIT functions is used

‘findorbit4’ (default)

‘findsyncorbit’

‘findorbit6’

ARGS - additioanl arguments may be passsed to some of the FINDORBIT functions

findorbit4 - constant momentum error dP

findsyncorbit - fixed orbit lengthening dCT

Returns a 1-by-4 cell array of O-by-P matrixes

where O = length(OBSINDEX) and P = length(PERTURB)

one for each of the close orbit components: X, PX, Y, PY

See also atparamgroup(), findorbit(), findorbit4(), findorbit6(), findsyncorbit()

findspos(ring, 1:length(ring))#: returns longitudinal positions of accelerator lattice elements.

Return value is a row vector of positions S at the entrance of each

element specified REFPTS (index list or logical mask)

Note: REFPTS is an array of increasing indexes that

select elements from range 1 to length(LATTICE)+1.

REFPTS is allowed to go 1 point beyond the

number of elements. In this case the last point is

the EXIT of the last element. If LATTICE is a RING

it is also the entrance of the first element after 1 turn.

Note:

1. Use findspos(ring,1:length(ring)) for to find

longitudinal position of all elements

2. Use findspos(line,length(line)+1) to find the

total physical length

3. If line is a closed ring, exit of the last element

is also the entrance to the first.