diff --git a/doc/latexuguide/ibs.tex b/doc/latexuguide/ibs.tex index 6a6247730..1c0eb1d5a 100644 --- a/doc/latexuguide/ibs.tex +++ b/doc/latexuguide/ibs.tex @@ -20,21 +20,17 @@ \chapter{Intra-Beam Scattering} to the case of nonzero vertical dispersion. The present implementation of the IBS module in \madx is described in a -forthcoming note \cite{antoniou-zimmermann2012}. +forthcoming note \cite{antoniou-zimmermann2012}. The syntax of the \texttt{IBS} command is: \madbox{ -%IBS, TOLERANCE=real, STEPS=integer, FILE=string; IBS, FILE=string; } The \texttt{IBS} command has one attribute: \begin{madlist} -% \ttitem{TOLERANCE} ??? (Default:~1.e-7) % declared, never used -% \ttitem{STEPS} number of steps ??? (Default:~50) % declared, never used - \ttitem{FILE} outputs the resulting "ibs" table to - the named file. (Default:~"ibs") + \ttitem{FILE} outputs the resulting "ibs" table to the named file. (Default:~"ibs") \end{madlist} The Bjorken-Mtingwa formalism takes into account the variation of the @@ -47,7 +43,7 @@ \chapter{Intra-Beam Scattering} \texttt{IBS} commands leads to \texttt{IBS} using wrong beam parameters, even if the \texttt{BEAM} command is reiterated. -The \texttt{IBS} module does not include a consistent treatment of +\textbf{Warning:} The \texttt{IBS} module does not include a consistent treatment of linear betatron coupling. The intra-beam scattering growth times are given by: @@ -65,7 +61,7 @@ \chapter{Intra-Beam Scattering} If the \texttt{CENTRE=true} option of \texttt{TWISS} was specified, the optical functions are calculated by \texttt{TWISS} at the center of each element and \texttt{IBS} uses these values for the element. -If by default \texttt{TWISS} calculated the optical functions at the end +If (by default) \texttt{TWISS} calculated the optical functions at the end of each element, \texttt{IBS} calculates the values at the center of each element by performing a linear interpolation between the end values for the previous element and the end values for the current element. @@ -129,20 +125,20 @@ \chapter{Intra-Beam Scattering} \textbf{Resulting Table and File:} \\ The \texttt{IBS} command produces a table "ibs" containing the following -data for -each element of the machine: element name, position, optical functions +data for each element of the machine: element name, position, optical functions (beta, alfa, dispersion and derivative) in both transverse planes, as well as the particular variables \texttt{DELS}, the length difference in -meters between consecutive elements, and \texttt{TXI, TYI} and -\texttt{TLI}, the IBS growth times in the two transverse and -longitudinal planes. +meters between consecutive elements. The table also containts the \texttt{TXI, TYI} +and \texttt{TLI} variables, values close to the IBS growth times at the element in +the two transverse and longitudinal planes. Exactly, these variables correspond to +the result of Eq (8) in~\cite{antoniou-zimmermann2012} without including the common +constant term (the first fraction). This table can be accessed through the usual mechanisms. If the attribute \texttt{FILE="file\_name"} is also given, \madx writes the table to the named file. - \textbf{Features:} \\ The average growth rates in [sec] are defined as variables called \texttt{ibs.tx}, \texttt{ibs.ty}, \texttt{ibs.tl} for the horizontal, @@ -150,9 +146,12 @@ \chapter{Intra-Beam Scattering} accessible as variables after the \texttt{IBS} command, e.g. \madxmp{ IBS; \\ -Tx = ibs.tx;} -defines a variable Tx which is the average horizontal growth rate in seconds. +Tx = ibs.tx;} +defines a variable Tx which is the average horizontal growth rate in seconds. +Additionally, the Coulomb logarithm as well as the aforementioned common +constant of Eq (8) in~\cite{antoniou-zimmermann2012} are also exported as +the \texttt{ibs.coulog} and \texttt{ibs.coulog} variables. \textbf{Examples:} \\