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%\input dspace12.tex
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\large
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\centerline {\bf 1.23\_V2.2 INTERNAL CALIBRATION SOURCE MEASUREMENT }
\vspace{0.25in}

\normalsize
\noindent{\it Last Revised: August 3, 1999}\\


\noindent {\bf BRIEF FUNCTIONAL DESCRIPTION:} \\
\normalsize
ACIS contains an Fe55 source inside its camera housing which 
continually illuminates the focal plane when the ACIS door is closed.
The source is highly
collimated so that most of the events occur on the S2 and S3
CCDs.  The Mn~L line strength will be compared to the Mn~K line
complex strength to judge any differences in sensitivity, compared
to ground calibrations.  The
count rate for the Mn~L line on the S3 chip will be 
$0.4~{\rm counts~s^{-1}}$ given an August 1999 launch date.  
The requirement is to acquire
10,000~counts in the Mn~L line; therefore an integration time
of 25~ks is required.  Since the other CCDs will not see a significant
number of Mn X-ray, we will use this time to collect background data on
them.  Half of the time will be spent on the I array and the other
half on the S array.  
There are four science runs in the procedure.
The first collects I array data in Faint mode with a g7 grade filter
and no event amplitude cutoff.
The second collects S array data in Faint mode with a g7 grade filter
and no event amplitude cutoff.
The third collects I array data in Faint mode with a b255 grade filter
and a 2900~ADU event amplitude cutoff.  It also employs a window block
to reject events from I0,I1,I2, and I3.  This run also varies the bias
parameters for I0--I3 in order to investigate the efficacy of the bias
algorrithms.
The fourth collects S array data in Graded mode with a b255 grade
filter
and no event amplitude cutoff.  It also employs a window block
to reject events from S0,S1,S4, abd S5.
{\bf We anticipate that the fourth science run will be routinely
skipped in flight operations}.


\vspace{0.25in}
\noindent The sequence of actions will be: 
\be
\item warm boot and start DEA housekeeping if necessary
\vspace{-0.10in}
\item configure the instrument to collect imaging array data, (no g7,
no event amplitude cutoff)
\vspace{-0.10in}
\item execute the faint mode science run
\vspace{-0.10in}
\item configure the instrument to collect spectroscopy array data
\vspace{-0.10in}
\item execute the faint mode science run, (no g7, no event amplitude cutoff)
\vspace{-0.10in}
\item configure the instrument to collect imaging array data
\vspace{-0.10in}
\item execute the faint mode science run, (no b255,  event amplitude
cutoff at 2900~ADU, only telemeter events from S2 and S3, bias
algorithm parameters vary for I0-I3, event threshold varies by
quadrant for S2)
\vspace{-0.10in}
\item configure the instrument to collect spectroscopy array data
\vspace{-0.10in}
\item execute the graded mode science run (no b255, no event amplitude
cutoff, employs a window to only telemeter events from S2 and S3)
\vspace{-0.10in}
\item return to thermal standby mode if necessary
\vspace{-0.10in}
\ee


\vspace{0.15in}
\normalsize
\noindent {\bf ASSUMED INSTRUMENT STATE:} \\
\normalsize
Assumes that the instrument is in the cannonical thermal standby mode.\\
Assumes that the ACIS door is closed.\\
Assumes that the standard patches have been loaded {either the
standard patches alone or the standard patches bundled with the
optional patches}. \\


%\vspace{0.25in}
\normalsize
\noindent {\bf SPECIAL INITIAL CONDITIONS:} \\
\normalsize


%\newpage 

%\vspace{0.25in}
\normalsize
\noindent {\bf OPERATIONAL CONSTRAINTS/CAUTIONS:} \\
\normalsize


\vspace{0.15in}
\normalsize
\noindent {\bf REFERENCES:} \\
\normalsize

\normalsize
\noindent {\bf CHANGE HISTORY:} \\
\normalsize

{\bf V1.0}
Original version, edited from procedure 1.17\_V1.2.
\begin{itemize}
\item Added step 1 to include a warm boot and start DEA HKP run
\item changed the expected value of the DPA A \& B and DEA A input
voltage  and changed the expected values of the 
DPA A \& B and DEA A input currents in steps 2.1 and 10.3
\item Move dumps to follow start science in steps 3.3 \& 5.3
\item Changed parameter blocks in steps 3.1 \&  5.1
\item Changed time per science run in steps 3.14 \& 5.14
\item Added two new, graded mode science runs in steps 7 \& 9
\item used command ``WSPOW00000'' in step 10.1 to power-down the video
boards and FEPs
\end{itemize}

{\bf V2.0}
\begin{itemize}
\item ACIS Team signed-off version
\item changed expected version number of flight SW to either 26 or 27
since either would be acceptable
\item changed expected value of ``1STAT7ST'' in step 1.6
\item changed time required for step 9.16 to 5~m
\item added comment in step 10.2 to verify that the FEPs and video
boards are off
\item edited first sentence in ``Brief Functional Description''
\end{itemize}

{\bf V2.1}
\begin{itemize}
\item step 3.1, changed the SW command mnemonic from ``WT000A6014'' to
``WT000DC014'' and the command identifier
\item step 5.1, changed the SW command mnemonic from ``WT000C2014'' to
``WT000E4014'' and the command identifier
\item step 3.1, changed the SW command mnemonic from ``WT000CC014'' to
``WT00144014'' and the command identifier
\end{itemize}

{\bf V2.2}
\begin{itemize}
\item Updated the text description to be consistent with the PB
changes of version 2.1
\end{itemize}

\newcommand{\tablecaptiontext}{Internal Calibration Source Measurements}
\input{intcal.tab}

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