\documentclass{chowto}

\title{Superharp Operation}
\howtotype{user} % ``expert'', ``user'', ``reference''
%\experiment{Name of experiment} % Optional
\author{M. K. Jones}
\category{beamline} % Subject area of this document
%\maintainer{Name of person maintaining document} % Optional
\date{July 7, 2003} % Can use \today as the argument

\begin{document}

\begin{abstract}
Describes how to take and analyze superharp data.
\end{abstract}

\section{Introduction}
This document is derived from the G0 superharp How-to by Junho Yun.

For more information about the super harp system, see the reference
``Hall C Superharp System''\cite{howto:superharp_system} by Chen Yan.

\section{Data taking}

\begin{enumerate}

\item Make sure beam is stable and 5 $\mu$A or less. For rastered
beam one can use up to 10~$\mu$A , but first try with 5~$\mu$A.
Let MCC know
that you are planning to do a scan.

\item {\it ssh cvxwrks@cdaqh1} with cdaq password

\item {\it cd g0superharp}
\item {\it cd scan\_data/spring03} and make a new directory for the
new date and run number of the data run. e.g. mkdir apr\_01\_03\_runnumber

\item {\it cd ../..} , so you are in the g0superharp directory.

\item type {\it harp\_launch}

\item In the GUI click on Calculate and choose Scan. A small medm window
will appear. Click on the {\it execute} button and then open the file
{\it Harp\_MEDM/g0superharp.adl } using the {\it file } menu. Then you will
get a GUI with the Superharp. For each superharp scan desired.

\begin{enumerate}
\item Click on blue button near desired superharp
\item Another gui pops up, click on the red scan button and then wait until
``Declared zero point harp position'' is displayed. Kill screen after scan
is done.
\end{enumerate} 

\item Now from the main GUI type {\it spring03} in the Experiment window
and the directory name ( that you set above) in the Filename window.

\item Click on File menu and select Load New Data.

\item Click on yellow button with one of the harp names and select
from the list which harp you want to look at. To clear screen
click on File menu and choose Reset. 

\end{enumerate}

\section{Analyze harps near target}
\begin{enumerate}
\item Assuming that you are in the g0superharp directory on cdaqh1
\item Type: make\_harp\_file {\it directory\_name} {\it run\_number} 
\item Type: use cernlib/2000
\item Type: paw
\item Depending if beam was unrastered or rastered. If the beam was unrastered and 
one wants to fit with a Gaussian then add {\it fit=yes} when 
execute  plot\_harp.kumac in next step. If the beam was rastered then
execute with {\it fit=no}.
\item In paw++ Executive window type: exec plot\_harp harpname=IHA3H00\_{\it runnum} fit={\it yes or no}
\item A plot of the raw harp scan is shown. Click with left mouse to make gates around each peak.
Click the right mouse to quit.  
The first peak is the x1 wire, the second is the y wire and the third is the x2 wire.
The program has offsets for each wire ( for spring 2003 these were determined
by comparison to the BPMs). For each of the following plots, the offset for that wire is
subtracted from the raw data and for the X1 and X2 the sign is reversed to agree the 
BPM sign conventions.
\item Then the x1 plot appears. If not doing a fit the
 left click at the lower left, center and upper left of the peak (click with right
mouse to quit). The kumac will return
the difference between the first and last position and the center position. For a
fit make a click in the flat region below the peak, at the left base of the peak,
at the top peak ( the y position
is used as the starting height), at the right base of the peak and  in the
flat region above the peak .
The fit is a constant background plus a Gaussian. 
Unfortunately fitting with PAW can sometimes have problems, and you just have do it
again. If you get a negative number for sigma you can just take the absolute
value since PAW uses the square and is insensitive to the sign. All units are mm.
\item Then the y plot appears. Do as for x1 plot.
\item Then the x2 plot appears. Do as for x1 plot.
\end{enumerate}

\end{document}

% Revision history:
% $Log: superharp.tex,v $
% Revision 1.5  2003/07/17 21:13:30  saw
% Add a Citation to the Superharp System reference
%
% Revision 1.4  2003/07/09 17:46:24  saw
% (jones) Some corrections
%
% Revision 1.3  2003/07/07 20:30:53  saw
% (jones) Add detail for paw++ analysis
%
% Revision 1.2  2003/04/10 16:50:07  saw
% (jones) Add procedure for harps near target
%
% Revision 1.1  2003/04/07 20:47:53  saw
% Initial checkin
%
