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Detailed chromatic analysis

Traces particles (2 per plane, per momentum) to determine the linearized transfer matrix from the initial point to any related point in the lattice. A twiss function computation is then done at these points. The initial central particle position is assumed to be $v_{0}=(x_{0}\ x'_{0}\ y_{0}\ y'_{0})$.

NOTE: no kicks simulating synchrotron oscillation (parameter $T < 0$ ) may exist in the lattice. Results are meaningless in the presence of such kicks. For each chosen momentum, particles are generated around the point $v_{0}$ to compute the elements $R_{ij}$ of the matrix describing the linear motion around the trajectory defined by the point $v_{0}$.


Input format 

DETAiled chromatic analysis...(up to 80 characters)
nh nv nhv
$x_{0}\ x'_{0}\ y_{0}\ y'_{0}$
$dx\ dx'\ dy\ dy'$
$\beta_{x} \alpha_{x} \eta_{x} {\eta '}_{x}$
$\beta_{y} \alpha_{y} \eta_{y} {\eta '}_{y}$
nener ncoef
$\delta_{1}\ \delta_{2}\ \dots\ \delta_{nener}$
mlocat [list]

Parameter definitions

nh

1 $\textstyle \parbox{10cm}{ only $x\ x'$\ motion
is traced and computed.
$\beta_{x}\ \alpha_{x}$\ and $\nu_{x}$\ are computed.}$

0 $\textstyle \parbox{10cm}{
$x\ x'$\ motion alone is not analyzed.}$

nv

1 $\textstyle \parbox{10cm}{
only $y\ y'$\ motion is traced and computed.
$\beta_{y}\ \alpha_{y}$\ and $\nu_{y}$\ are computed.}$

0 $\textstyle \parbox{10cm}{
$y\ y'$\ motion alone is not analyzed.}$

nhv

1 $\textstyle \parbox{10cm}{
coupled motion $x\ x'$, $y\ y'$\ is traced. The full beam
matrix is computed.}$

2 $\textstyle \parbox{10cm}{
coupled motion is computed. A short print
for $x\ x...
...a_{x}\ \beta_{y}\ \alpha_{y}\
\nu_{x}\ \nu_{y} $\ for all energies requested}$

3 $\textstyle \parbox{10cm}{
in this case three energies have to be defined :
\par...
...value is 1.0. When set to
1.0e03(say)) the printed values are in mm and mrad.}$

4 $\textstyle \parbox{10cm}{
The beam matrix values (as defined in the BEAM
opera...
...he scale factor SIGFAC
which can be set via the constant defintion operation.}$

5 $\textstyle \parbox{10cm}{
same as three with the code added in the first column
to facilitate some plotting work}$



0 $\textstyle \parbox{10cm}{
coupled $x\ x'$, $y\ y'$\ motion is not analyzed.
When NH, NV, and NHV are all zero, the program prints the
centroid positions only.}$

NOTE: the input beam must have been defined previously in a BEAM MATRIX TRACKING operation.

dx dx' dy dy'

$\textstyle \parbox{10cm}{
increments at which the off orbit particles are placed
to compute the sx, cx, sy, cy functions (see
reference \cite{klb}
).}$

$\beta_{x}\ \alpha_{x}\ \eta_{x}\ {\eta '}_{x}\
\beta_{y}\ \alpha_{y}\ \eta_{y}\ {\eta '}_{y}$

$\textstyle \parbox{10cm}{
initial values used in the twiss function computations.}$

nener

$\textstyle \parbox{10cm}{ number of energies for which the analysis
is done (maximum 15).}$

ncoef

$\textstyle \parbox{10cm}{
number of coefficients used in the Taylor
series expansion as a function of momentum (max 6).}$

$\delta_{1} \dots \delta_{nener}$

$\textstyle \parbox{10cm}{momentum values }$

mlocat

$\textstyle \parbox{10cm}{
indicates the number of intervals in which printing ...
...T = -1, then printing occurs at end
of lattice only and no number is in list.}$

list

$\textstyle \parbox{10cm}{contains the beginning and end of all
intervals in wh...
...der list of machine
elements) List may contain up to mxlist pairs of numbers.}$



Examples

The first example, taken from demo7, produces a multiple momentum analysis of the beam centroid and beam matrix at the end of the lattice.

The second example, taken from demo9, gives a "short" printout of the beam centroid and the twiss parameters at every point of the lattice, for the on momentum motion.

DETAILED CHROMATIC ANALYSIS
1 1 1
0 0 0 0
0.000001 0.000001 0.000001 0.000001
49.26950355 0 0 0 22.75617615 0 0 0
7 5
0.0 -.001 0.001 -.003 0.003 -.005 0.005
-1,

detailed
1 1 2
0 0 0 0
1.0e-06 1.0e-06 1.0e-06 1.0e-06
1.76806 -0.0032 0 0
15.0736 -0.0034 0 0
1 0
0.00
0;
stop


next up previous
Next: Generation of particles Up: Use and description of Previous: COSY translation
Dobrin Kaltchev 2004-10-20