\chapter{XRCF and the HETG} \label{chap:xrcf_intro} \section{XRCF Introduction} During December 1996 through April 1997 all three key components of the HETGS, HRMA-HETG-ACIS-S, were integrated for test at NASA's Marshall Space Flight Center (MSFC) in their X-Ray Calibration Facility (XRCF). The XRCF and related hardware are described in great depth in the documents listed in Table~\ref{tab:xrcf_docs}, however some key concepts are presented here for completeness and to support the grating analysis discussion. \begin{table}[h] \caption{\small XRCF Documents and References} \label{tab:xrcf_docs} \begin{center} \begin{tabular}{ccc} \hline XRCF Phase 1 Testing: Preliminary Results & MST & June 1997 \\ Calibration of the AXAF: Project Science Analyses & Weisskopf {\it et al.} & October 1997 \\ \hline \end{tabular} \end{center} \end{table} The general layout of XRCF hardware is shown in Figure~\ref{fig:xrcf_setup} and specifics of the key subsystems are presented below. Calibration was divided into two main calibration phases, Phase I and Phase II, defined physically by differences in the focal plane detectors; the Beam normalization detectors (BND) were present in both Phases. Each of these major phases had subphases designated sequentially by letter, see Table~\ref{tab:xrcf_phases}. \begin{table}[h] \caption{\small XRCF Phases and Detectors} \label{tab:xrcf_phases} \begin{center} \begin{tabular}{ccc} \hline Phase & Focal Plane & Comments \\ \hline \hline R & FPC, SSD, HSI & TMA and TOGA \\ I-C & FPC, SSD, HSI & \\ I-D & FPC, SSD, HSI & \\ I-E & FPC, SSD, HSI & \\ II-F & ACIS-2C & \\ II-G & HRC and '2C & \\ II-H & ACIS & \\ II-I & ACIS & Flat fields, no HRMA \\ J & FPC, SSD, HSI & HXDS detector cross-calibrations \\ \hline \end{tabular} \end{center} \end{table} In Phase I the non-flight detectors, FPC\_X2 (Flow Proportional Counter), SSD\_X (Solid State Detector), and HSI (micro-channel plate High Speed Imager), were in the focal plane. The philosophy of Phase I is that the detectors are (or will be) well characterized and of proven and understood technology so that measurements are performed to understand the HRMA and gratings. Grating-in grating-out measurements were performed to measure grating Efficiency; images and scans were obtained to verify the grating LRF model. In Phase II a ``two-chip ACIS'' (ACIS-2C) and the flight ACIS and HRC detectors were variously present. Here the philosophy is that the HRMA and gratings are understood and the flight detectors and/or the HRMA-(grating-)detector interaction is being studied. For this reason, the HETG tests were primarily related to Effective Area. Because LRF tests generally require well focussed beams and given the HRC pore extraction limits and the ACIS telemetry limits, extensive LRF studies were not in general carried out with the HETG in Phase II -- the exception being enough data with ACIS-S to allow us to verify the Rowland curvature of the CCDs. \begin{figure}[p] \begin{center} \epsfig{file=xrcfsetup.eps,height=5.5cm} \caption[XRCF hardware schematic] {\small XRCF hardware schematic. The XRCF HETG configurations include i) X-ray source and filters, ii) Beam normalization detectors (BNDs), iii) AXAF optics (HRMA, HETG), iv) shutter assembly, and v) focal plane detectors.} \label{fig:xrcf_setup} \end{center} \end{figure} \begin{figure}[p] \psfig{file=phase1_effic.ps,height=7.5cm} \caption[Phase 1 Hardware Schematic] {\small Phase 1 Hardware Schematic. In all phases the incident source flux is monitored by a set of beam monitor detectors (BNDs), four of which are located around the HRMA entrance aperture, shown at left. One or the other of the AXAF gratings, HETG or LETG, may be inserted into the converging HRMA beam. In Phase 1, detectors of similar design to the BNDs are located in the focal plane and can be positioned through 3-axes of motorized stages, {\it e.g.}, to follow the HEG Rowland circle shown by the dashed curve. } \label{fig:phase1_setup} \end{figure} \subsection{XSS} \label{sec:xss} Details of the X-Ray Source System (XSS) are presented in Kolodziejczak {\it et al.}~\cite{jeffk95}. \subsection{Double Crystal Monochromator (DCM)} \label{sec:xss_dcm} The DCM is part of the X-ray Source System (XSS) used at XRCF~\cite{swartz98,jeffk95}. It offered three 3 different crystals for these tests, of which we only used the Thallium Acis Phthlate (TAP) between 0.9 and 2.5 keV and the germanium (Ge111) between 2.5 and 8.7 keV. The source is a rotating-anode tungsten source, which operates at a high voltage to generate a strong continuum, however it also produces several bright W lines at 1.38, 1.78, and 1.84 keV. Those lines actually proved quite useful for tests of HETG scattering, Sections~\ref{sec:scatter} and~\ref{sec:scat_theory}. The DCM has an energy gradient in dispersion direction, which results in a non-negligible beam non-uniformity when tuned near the the W lines. Another source of non-uniformity is introduced while using the TAP crystal due to some waviness on the crystals surface. \subsection{BNDs} \label{sec:bnds} The beam normalization detectors (BNDs) monitor the source flux without the effects of the HRMA or HETG. There are six BND detectors: two, a Flow Proportional Counter (FPC) and a Ge solid state detector (SSD), are located 37.43 and 38.20 meters from the source in ``Building 500'', and four FPCs surround the HRMA entrance, see Figure~\ref{fig:phase1_setup}. To ensure some BND data is available over a wide range of source flux, apertures can be selected on the FPC\_5, SSD\_5, and FPC\_HN BNDs. \subsection{HRMA, Gratings, and Shutters} The HRMA, gratings and shutters were all mounted to a common platform at XRCF. Some useful XRCF HETG parameters are tabulated in Table~\ref{tab:params} for reference. \begin{table} [h] %>>>> here, top, bottom, page_of_floats \caption[Table of useful XRCF HETG parameters] {\small Table of useful XRCF HETG parameters. These preliminary values are based on sub-assembly and XRCF testing.} \label{tab:params} \begin{center} \begin{tabular}{|c||c|c|c|c|} \hline %---------------------- \rule{0pt}{2.5ex} Description & value & error & units & comments \\[0.2ex] \hline %---------------------- Rowland distance & 8782.8 & 0.5 & mm & see Section~\ref{sec:hetg_location_at_xrcf} \\ \hline %---------------------- MEG average period & 4001.41 & $\approx $ 0.10 & $\AA $ & based on lab measurement \\ HEG average period & 2000.81 & $\approx $ 0.05 & $\AA $ & LR/NIST: based on lab measurement \\ \hline %---------------------- MEG angle & 4.74 & 0.05 & deg.s & \\ HEG angle & $-5.19$ & 0.05 & deg.s & \\ \hline %---------------------- MEG-HEG angle & 9.934 & 0.008 & deg.s & \\ (MEG+HEG)/2 angle & -0.225 & 0.01 & deg.s & (-0.275 in Phase C) \\ \hline %---------------------- \end{tabular} \end{center} \end{table} \subsection{HXDS Focal Plane System} \label{sec:hxds} In Phase I the non-flight detectors, FPC\_X2 (Flow Proportional Counter), SSD\_X (Solid State Detector), and HSI (micro-channel plate High Speed Imager), were in the focal plane. \subsubsection{HXDS Axes} The HXDS axes are nominally along the XRCF coordinates, Figure~\ref{fig:phase1_setup}. The HXDS primeY axis, however, was determined after-the-fact to have had its axis rotated by an angle of 0.0058 radians about $+Z_{\rm xrcf}$. Thus a commanded motion in the $+Y_{\rm xrcf}$ direction resulted as well in a motion of $0.0058\times \Delta Y$ in the $-X_{\rm xrcf}$ direction. \mx ~ simulations of XRCF measurements must take this into account. \subsubsection{HSI in the Focal Plane} \label{sec:hsi} During Phase I calibration the HSI detector\cite{evans97} provided imaging capability at high event rates, for example the image in Figure~\ref{fig:mis_aligned}. The HSI also was fitted with a mask with a ``cusp'' to allow the bright PSF core to be occulted while the surrounding wings of the PSF were observed. \subsection{FPC and SSD in the Focal Plane} \label{sec:fpc_ssd} The FPC and SSD are non-imaging detectors with moderate energy resolution and have a variety of apertures used to isolate and measure grating-dispersed spectral features in the focal plane, {\it e.g.}, the aperture of diameter $D$ in Figure~\ref{fig:phase1_setup}. These detectors have well studied characteristics\cite{wargelin97,mcdermott97}, are similar to the BNDs, and provide some of the fundamental data for characterizing the efficiencies and effective area of the system without the novelty and complication of the flight-detectors and their $QE(E,\dots )$ terms. The FPC and SSD detectors could have a slit aperture selected for use - in this way a direct measurement of the 1D LRF was possible, Section~\ref{sec:lrf_core} \subsection{ACIS-2C} \label{sec:acis2c} Extensive LRF tests could be performed with the ACIS-2C detector given its (non-flight) high event-rate readout. \subsection{ACIS} ACIS was installed in XRCF with its $+Z$ axis pointing in the $-Z_{\rm xrcf}$ direction. \subsection{HRC} \clearpage \section{Differences between XRCF and Flight} The arrangement and operation of the components at XRCF are flight-like with the following differences: \begin{quotation} \noindent $\circ$ The source is not infinitely far away and so i) the HRMA focal length is greater than the flight value and ii) the HRMA reflection angles and optic illumination are different from flight. \\ $\circ$ The HRMA is in a ``1-g off-loaded'' condition approximating the 0-g flight configuration, so flight PSFs will be slightly different. \\ $\circ$ The $+Z$ axis of the HRMA, gratings, and flight detectors pointed ``down'' at XRCF, ({\it i.e.}, aligned to XRCF $-Z$). \\ $\circ$ The gratings are designed to operate at a Rowland distance of 8633.69 mm but because of the HRMA focal length change they are placed $\approx 8800$~mm from the focus; this introduces negligible LRF effects and some slight additional vignetting, primarily for the LETG ($<5\%$). \end{quotation} \subsection{HETG Location at XRCF} \label{sec:hetg_location_at_xrcf} The Rowland spacing of the grating is the on-axis Rowland circle intercept to focal plane distance. This spacing must be inferred from measurements between the HETG and HRMA as well as assumed/measured location of the HRMA focus w.r.t. the HRMA fiducial location, {\it e.g.}, CAP center line. In order to put measured values into context it is important to have various axial reference points of the HRMA and gratings well defined and specified relative to each other; these references are tabulated in Table~\ref{tab:axial_refs}. \begin{table}[hb] \begin{center} \begin{tabular}{|cc|} \hline \hline {\bf HETG Axial References} & {\bf $X_g$ } \\ \hline $X_g=0$ & 0.0 \\ HESS/GESS surface (metrology reference) & 0.800 inches \\ ARM reflective surface & 1.500 inches \\ OTG Datum -D- alignment pad surface & 1.670 inches \\ Rowland intercept & 2.500 inches \\ \hline \hline {\bf HRMA Axial References} & {\bf X w.r.t. CAP CL} \\ \hline CAP CL (midplane) & 0.0 \\ HRMA node & 0.371 inches \\ CAP Datum -A- & 0.9825 inches \\ XRCF ARM & 2.846 inches \\ \hline \hline \end{tabular} \label{tab:axial_refs} \caption{\small Axial references for HETG and HRMA.} \end{center} \end{table} The following equation gives the Rowland spacing in terms of other measurable values: \begin{equation} {\rm (RC~spacing) = (Focus~to~CAP~CL) ~-~ (CAP~CL~to~OTGorg) ~+~ (OTGorg~to~RC) } \end{equation} Values for these quantities are tabulated, Table~\ref{tab:rc_spacing}, for three cases: \begin{itemize} \item (i) XRCF design drawing (301331) \item (ii) drawing plus a 0.392 inch shim designed to improve the vignetting performance of the gratings designed to improve the vignetting performance of the gratings \item (iii) post-XRCF values inferred from HRMA ARM to OTG ARM laser ranger measurements and improved HRMA focal length value \end{itemize} \noindent The later of these is TRW's best value for the as-used spacing at XRCF. The error on the Rowland Spacing at XRCF is at least 0.5 mm due to error in determining the "Focus to CAP CL" distance. Additionally, the "CAP CL to OTGorigin" distances were measured with a laser ranger, measuring the distance between the grating ARM reflective surface and the HRMA "XRCF ARM" surface. This measurement requires compensation for traversing the HRMA XRCF ARM glass substrate - systematics here could allow a common axial shift of both the HETG and LETG. \begin{table}[hb] \begin{center} \begin{tabular}{|c|cccc|} \hline \multicolumn{2}{|c}{RC spacing} & Focus to CAP CL & CAP CL to OTGorg & OTGorg to RC \\ mm & inches & inches & inches & inches \\ \hline \hline & \multicolumn{4}{|c|}{\it (i) Drawing 301331:} \\ 8772.83 mm & 345.387 & 403.5 & 60.613 & 2.5 \\ & \multicolumn{4}{|c|}{\it (ii) Drawing 301331 with 0.392 shim:} \\ 8782.79 mm & 345.779 & 403.5 & 60.221 & 2.5 \\ & \multicolumn{4}{|c|}{\it (iii) Measurements with laser ranger:} \\ 8787.99 mm & 345.984 & 403.512 & 60.028 & 2.5 \\ \hline \end{tabular} \label{tab:rc_spacing} \end{center} \end{table} X-ray measurements at XRCF, Section~\ref{sec:periods_angles}, have been used to verify the grating periods and Rowland spacing. Fits to the XRCF data using a Rowland spacing of 8788.04 mm (the mean of the HETG and LETG spacings of type (iii) above) show a discrepancy between the HEG/MEG sub-assembly periods and the X-ray derived periods. Because {\it both} the HEG and MEG periods appear in error by the same fraction, an HETG Rowland spacing error is a more simple explanation than coincident period errors. The Rowland spacing which agrees with the data is close to the expected design value given by case (ii) above. To minimize the number of Rowland spacing values kicking around, the current working hypothesis is that the HETG was installed at XRCF with a Rowland Spacing of 8782.8 mm. The origin of the difference between HETG and LETG XRCF Rowland spacings remains a mystery. \subsection{HETG Orientation at XRCF} The drawing of Figure~\ref{fig:hetg_drawing} {\bf when turned upside down} shows the HETG as oriented at XRCF. The view will then be from the HRMA towards the HETG with the +Z\_facility (Up) at the top of the (flipped) page and +Y\_facility (South) is to the right. This orientation is rotated 180 degrees about X from the Lab and Flight orientations. Grating facet locations are given by a code such as 6EE3 where: \begin{tabbing} space over \= space over \= \kill \> The leading digit is the shell number (1,3,4,6). \\ \\ \> The next one or two letters specify the sector \\ \> (designated A, B,..., F, AA, BB,..., FF).\\ \> For the {\bf XRCF orientation}: \\ \> \> sector A is between 9 and 8 o'clock \\ \> \> sector B is between 8 and 7 o'clock \\ \> \> ... \\ \> \> sector F is between 4 and 3 o'clock \\ \> \> sector AA is between 3 and 2 o'clock \\ \> \> sector BB is between 2 and 1 o'clock \\ \> \> ... \\ \> \> sector FF is between 10 and 9 o'clock. \\ \\ \> The final number gives the grating location within \\ \> the sector (numbered 1,2,... increasing in CCW direction, \\ \> {\it i.e.}, grating 1 is the most clockwise in a given sector.) \\ \end{tabbing} When used with the XRCF shutters the following HETG sectors are illuminated: \begin{tabular}{ll} Shutter & Illuminated Sectors \\ \hline Top & BB high-numbered half, CC, DD, EE low-numbered half \\ North & EE high-numbered half, FF, A, B low-numbered half \\ Bottom & B high-numbered half, C, D, E low-numbered half \\ South & E high-numbered half, F, AA, BB low-numbered half \\ \end{tabular} \clearpage \section{Summary of HETG XRCF Measurements} \label{sec:meas_summary} To support semi-automated test operation, the measurements to be made at XRCF were specified as rows in a 92 column tab-delimited ASCII file. These 92 columns specified nearly completely the desired state of the source, filters, HRMA, gratings, shutters, normalization detectors, and focal plane detectors. Testing proceeded through sequentially ``executing'' lines of this Calibration Measurement Data Base (CMDB). An as-run (or at least ``as-requested''---modifications could be made manually in real time) version of the CMDB is now a useful starting point in understanding what data were taken. The measurements (lines or rows of the CMDB) were assigned a ``measurement type'' which both specified a general focal plane hardware operating mode (Phase I in particular) and indicated the scientific purpose of the measurement. Tables~\ref{tab:summary1} and \ref{tab:summary2} provide a summary of all data taken at XRCF with the HETG inserted in the optical path and an indication of their use and data volume (number of measurements in brackets.) These tables with hyper-links to CMDB summaries are available on the web at: \begin{center} {\tt http://space.mit.edu/HETG/mtab/meas\_table.html} \end{center} \subsection{Efficiency Measurements} \label{sec:xrcf_intro_effic} The measurement types related to effective area break into two main divisions: {\it i}) quasi-monochromatic measurements: types EE (encircled energy), EA (effective area), and 3D(an automated version of EA); and {\it ii}) ``Molecular Contamination'' (MC) measurements where the broad-band continuum produced by the source is utilized (see the MC example in Section 7.3). The distinctions between EE, 3D(EA), and EA are primarily in Phase I and represent different methods of placing the focal plane hardware at the desired location: in EE a ``beam-center'' is performed to set the aperture(s) relative to the reference location specified in the CMDB; in 3D(EA) measurements, one or more locations are sampled in the focal plane at coordinates specified by a locations file; and in EA the location is specified in the CMDB. A valuable fraction of the data were taken while one of the XRCF monochromators was scanned in energy. Although scientifically similar to non-scanned data, these data are more difficult to analyze because there was no direct synchronization between the source scan and the data collection. These all have measurement type EA. Finally, the ``Alignement'' test was originally designed to set limits on vignetting due to (unplanned) decentering of the HETG at XRCF. Because of the MEG misaligned gratings, the alignment test performed on high order became a tool for LRF diagnosis. \subsection{LRF Measurements} Phase I LRF measurements were performed with the HSI generally and with the FPC fitted with slits with a Mg-K source (``PSF/1-D''). In Phase II, the ACIS-2C was used extensively for PSF/Inner tests. \begin{quotation} {\it To-do:} \\ description of TRW ID fields \\ IDL CMDB s/w description \\ Apendix with CMDB summary for each of the measurement types (or put these in respective analysis sections.) \end{quotation} \begin{table} [h] %>>>> here, top, bottom, page_of_floats \caption[Summary of HETG XRCF Measurements in Phase I] {\small Summary of HETG XRCF Measurements in Phase I. Number of measurements is shown in brackets.} \label{tab:summary1} \begin{center} \begin{tabular}{|c||c|c|} \hline %---------------------- Type & \multicolumn{2}{|c|}{Detector} \\ \hline %---------------------- \rule{0pt}{2.5ex} & FPC/SSD & HSI \\[0.2ex] \hline %---------------------- {\it LRF-related}\hfill ~.~.~.~ & & \\ FC and SF & - & Verify focus, check PSF [16] \\ dFocus & - & Defocus and in-focus images [2] \\ Alignment & - & Gross vignetting, mis-aligned gratings [3] \\ PSF/1D & LRF core, wings [21] & - \\ PSF/Outer & - & Wings, scatter [8] \\ 3D (Offaxis) & - & Offaxis images [6] \\ \hline {\it Eff.area-related}\hfill ~.~.~.~ & & \\ EE & Order locations, effective area [33] & - \\ 3D (EA) & Effective area, high orders [56] & Source spectra, MEG-Penning PSF [32] \\ EA (fixed E) & Effective area [10] & Source spectra (incl. DCM, HIREF) [9] \\ EA (mono scan) & Effective area [19] & - \\ 3D (Molecular & - & Identify and search \\ ~~~~Contamination) & & for edges, etc. [6] \\ \hline %---------------------- \end{tabular} \end{center} \end{table} \begin{table} [h] %>>>> here, top, bottom, page_of_floats \caption[Summary of HETG XRCF Measurements in Phase II] {\small Summary of HETG XRCF Measurements in Phase II. Number of measurements is shown in brackets.} \label{tab:summary2} \begin{center} \begin{tabular}{|c||c|c|c|} \hline %---------------------- Type & \multicolumn{3}{|c|}{Detector} \\ \hline %---------------------- \rule{0pt}{2.5ex} & ACIS-2C & HRC & ACIS \\[0.2ex] \hline {\it LRF-related}\hfill ~.~.~.~ & & & \\ FC and SF & Verify/check focus [7] & Verify/check focus [1] & - \\ dFocus & Find best focus [10] & - & - \\ PSF/Inner & Core, wings; & - & Core, wings; \\ & offaxis images [23] & & offaxis images [8] \\ Scattering & Wings, scatter [5] & - & Grating scatter, pileup effects, \\ & & & readout modes (, eff. area) [7] \\ \hline {\it Eff.area-related}\hfill ~.~.~.~ & & & \\ EA (fixed E) & Effective area [133] & Effective area [33] & Effective area [11] \\ EA (mono scan) & Effective area [29] & Effective area [1] & Effective area [9] \\ MC (Molecular & Identify and search & - & Identify and search \\[0.2ex] ~~~~Contamination) & for edges, etc. [53] & - & for edges, etc. [5] \\[0.2ex] \hline %---------------------- \end{tabular} \end{center} \end{table} \clearpage \section{Examples of XRCF Data} With complicated data it is best to start with an image---and so in Phase I we generally took images of the diffracted X-rays with the High Speed Imager (HSI). Figure~\ref{fig:alk_meg_hsi} shows the HSI image of the Al-K line in the MEG 3rd order---deflected 55 mm from the zero-order (HRMA focus) location. These are the ``raw'' HSI data and show the instrumental ``gaps''\cite{evans97}, {\it e.g.}, one goes through the K-$\beta$ peak. Note that the ``line'' in fact consists of several discrete lines as well as continuum. The ``satellite'' line just shortward of the K-$\alpha$ peak has been previously observed during XMM grating testing\cite{paerels94}; we also observe a second, weaker satellite line at 8.22\AA . \begin{figure} \begin{center} \epsfig{file=alkmeghsi.eps,height=14cm} \caption[HSI image of 3rd-order MEG Al-K line] {\small HSI image of 3rd-order MEG Al-K line (top) and the resulting grating-produced spectrum (bottom). Note that all of this spectral structure is unresolved by the FPC and SSD detectors, Figure~\ref{fig:pha_meg_example}. A strong ``satellite'' line is clearly visible near the K-$\alpha$ peak. HSI instrumental gaps have not been removed, {\it e.g.}, at the K-$\beta$ line.} \label{fig:alk_meg_hsi} \end{center} \end{figure} To accurately measure the intensity of the line in Phase I, the FPC\_X2 (or SSD\_X) with selected aperture could be moved to the line center and the pulse-height histogram of events through the aperture measured. An example of the acquired focal-plane and BND histograms is shown in Figure~\ref{fig:pha_meg_example} for the MEG first order of Al-K and a 500~$\mu$m diameter aperture. Note that while the BNDs are able to resolve an Al-K peak and broadband continuum, the detailed spectral structure of the Al-K line is unresolved. The 500~$\mu$m first-order aperture size corresponds spectrally to the region within the 1500~$\mu$m circle shown in Figure~\ref{fig:alk_meg_hsi}---thus the FPC\_X2 is detecting the K-$\alpha$ and satellite lines and some continuum, but is excluding other continuun and the K-$\beta$ peak. In Phase II the focal plane detectors were all imaging instruments (ACIS-2C, ACIS, and HRC) and so provide their own source spectral diagnostics. Effective area measurements generally did not required precise positioning; in fact, because of per-pixel count-rate limits (set generally by pile-up for ACIS and dose limits for HRC) the measurements were performed with a large defocus. Figure~\ref{fig:alk_heg_2c} shows an ACIS-2C image of the HEG first-order of Al-K. The defocussed images of the HRMA shells 4 and 6 are modulated by the individual grating facets. Because of the defocus, extraction of the K-$\alpha$ events will necessarily be contaminated by the existence of the other lines and continuum. HRC and ACIS effective area data are very similar to this ACIS-2C example as the ACIS-S event plot of Figure~\ref{fig:acis_ea_alk} demonstrates. \begin{figure} \begin{center} \epsfig{file=phamegexample.eps,height=14cm} \caption[Example Phase 1 PHA spectra] {\small PHA spectra from Al-K MEG +1 order measurement. The focal plane FPC\_X2 shows only a monochromatic response (with a slight pile-up peak at $2E$) while the beam normalization detectors (FPC\_HN, FPC\_5, and SSD\_5) show both the Al-K ``line'' and broad-band (unfiltered) continuum.} \label{fig:pha_meg_example} \end{center} \end{figure} \begin{figure} \begin{center} \epsfig{file=alkheg2c.eps,height=9cm} \caption[ACIS-2C defocussed image of Al-K line] {\small ACIS-2C defocussed image of HEG dispersed Al-K line. Note that the same line components as in Figure~\ref{fig:alk_meg_hsi} are present.} \label{fig:alk_heg_2c} \end{center} \end{figure} \begin{figure} \begin{center} \epsfig{file=aciseaalk.eps,height=3.5cm} \caption[ACIS-S defocussed image of Al-K line] {\small ACIS-S defocussed image of HETG dispersed Al-K line. The HEG and MEG diffracted orders are clearly identified by the corresponding HRMA shells in their images. For the MEG, orders $m=\pm 1, \pm 2, \pm 3$ are visible.} \label{fig:acis_ea_alk} \end{center} \end{figure} \clearpage \section{Status of the HETG XRCF Analysis} The table below summarizes the status of the HETG XRCF analysis efforts. Only a few of the measurement projects listed here have reached the level of ``adequate'' analysis. Analysts are generally from the HETG and ASC/MIT groups; brackets indicate contributors expected beyond this preliminary report. \begin{table}[h] \caption{\small Status Code} \label{tab:status_code} \begin{center} \begin{tabular}{|l|l|} \hline Status code & Analysis status \\ \hline - & not yet analyzed \\ X & very preliminary analysis \\ XX & adequate analysis \\ XXX & complete analysis \\ \hline \end{tabular} \end{center} \end{table} \begin{table}[h] \caption{\small Status of HETG XRCF analyses} \label{tab:status} \begin{center} \begin{tabular}{|c|l|l|l|} \hline Section & Analysis Effort & Analyst(s) & Status \\ \hline \hline & & & \\ & \multicolumn{1}{|c|}{\it LRF:} & & \\ \ref{sec:periods_angles} & Periods and Angles & dd & XX \\ \ref{sec:lrf_core} & Core: Period and Roll Variations & dd & x \\ \ref{sec:mis_align} & MEG mis-aligned gratings & dd, hlm & XX \\ \ref{sec:core_scatter} & Between Core and Scatter & [dd, hlm] & - \\ \ref{sec:scatter} & Scatter & hlm,dd & Xx \\ \ref{sec:offaxis_defocus} & Offaxis and Defocus & [dsd, wise] & - \\ \ref{sec:acis_rowland} & ACIS Rowland Conformance & [kaf] & - \\ & & & \\ & \multicolumn{1}{|c|}{\it Efficiency and Effective Area:} & & \\ \ref{sec:align} & Alignment Tests & dd & X \\ \ref{sec:xrcf_sources} & XRCF Source Characteristics & dd & Xx \\ \ref{sec:effic_phase1} & Phase 1, Fixed Energies & dd & Xx \\ \ref{sec:effic_2c} & ACIS-2C Data & dd & x \\ \ref{sec:effic_mono} & Phase 1, Monochromator Scans & [dd] & - \\ \ref{sec:area_acis} & Area with ACIS-S & [jhk, nss] & - \\ \ref{sec:effic_mc} & Molecular Contamination & dd, [hlm] & X \\ \ref{sec:area_hrc} & Area with HRC-I & [kaf] & - \\ \ref{sec:effic_highorders} & High-Order Efficiencies & [kaf,nss] & x \\ \hline \end{tabular} \end{center} \end{table}