To HETG at XRCF page
Simulation Notes / Status
- 10/21-22: Add Be and Penning simulations. Add BND simulation. Add
nice html output to see and move around in the simulations. Penning
as integral 0.5 um C8H8 filter (in addition to filter wheel).
- 10/19: Flip HSI mask to agree with reality. Add HSI 1.6 mm offset.
Add "cusp1" hsi_pos specification. Add Mg and Be filters.
- 10/18: Add HSI,FPC, and SSD to simulation.
The HSI uses the HRC-S model
in MARX, note that an energy histogram of detected events is available and
has no energy blurring. A simple digitization
of the HSI mask is included
The SSD is simulated by using the ACIS-S model in MARX and includes ACIS frontside efficiency and energy blur.
is simulated by an ideal HRC-S (effic = 1. and no blurr) followed by
my own simple Ar prop counter efficiency and blur.
For the FPC and SSD a circular aperture is used. If an aperture list
was specified then 500 um is used. (This is roughly geometric mean
between 5 um and 35000 um!) If a slit is specified then a 200 um
circle is used.
- 10/10: Add plots of the input source spectrum used.
- 10/8: Add C and O contamination lines to all targets.
- 10/8: Put the gratings at observed angles w.r.t. ACIS: HEG=-6.9 deg.,
LEG=-1.9 deg., and MEG=3.1 deg.
- 10/2: Aim point and Y sign
Re-running simulations so that the nominal
ACIS-2C aim point and the Y sign
convention are accurate in the simulations.
- 10/2: Simulate upcoming measurements
Thanks to Hank for putting the .cal
and .order files in Cambridge! Redo the simulations in test order. *** Use
CMDB values of Y offset for all measurements (no sign switch for TOGA measurements
simulated after this date.) ***
- 10/1: Monochromators included
Use approximation to monochromators - narrow band
filter after a W (or C) source. Have E/dE fixed at 300 and put in higher orders
at 3%, 0.5%, 0.7%, 0.3% for orders 2-5. Also included an overall 10^-6 transmission
off the tuned energy (so will see some leakage of the 1.77 keV line too.)
- 10/1 3pm: Added filters.
Filters have been added and all EIPS simulations re-run.
The Al filter really makes the LEG cross-dispersion spots show up well!
- 9/30: First simulations.
The source spectra are simple
Karamers plus lines developed for X-GEF (HETG subassembly tests). No
filters were included in the simulations.
Very simplistic simulations of most of the EIPS Phase 2
measurements are available. These were made using an IDL procedure,
toga_full_sim, to run csim/MARX (a product of ASC-MIT) using the TMA/TOGA csim parameter files
to do spatially
accurate TMA and TMA/TOGA simulations.
The simulations do try to give a reasonable idea of the image distortion due
to the multiple exposure of the '2C windowlets. For ease of display the chip
spatial coordinate is in "millifractions": 1000 millifractions equals one chip
active-area width or 1.024 pixels per millifraction.
The non-grating spatial linearity tests were falling off the simulation suggesting
I had the nominal aim point in the wrong quadrant(?): third quadrant of
chip is really "second quadrant" of idealized chip because the real chip is upside down?!?
Now assuming that the aim point is to the left = North = minus Y of chip center
when looking at the chip from source.
Each simulation is a directory with the following .gif files (listed in alphabetical
order as shown by the viewer):
This gives an energy histogram of all the photons that land
on the chip, some nominal gaussian vs energy blur is included for the CCD response.
This is an event scatter plot in chip Y,Z coordinates with
Y restricted to the chip range and Z aliased to the size of the readout-mode windowlet.
This is a histogram of the Y coordinate of all the chip-detected
This is a scatter plot of the chip measured
energy plotted vs the
Y location on the chip.
For added perspective this and the next plot are shown in
Facility coordinates (i.e. for TMA optical axis at Y=0,Z=0). This plot of E
vs Y shows all the various gratings orders as hyperbolic curves.
Alphabetically last, this is perhaps the best starting
point to understanding what is going on: the facility Y,Z locations of events are
shown as well as the location and size of the '2C chip and windowlet.
Plot of the source spectrum incident on the
TMA used in the simulation; this is exactly the spectrum what csim receives.
Simulation To Do
Although primarilly implemented to help with Phase 2 rehearsal (and so changes
after Oct.5 don't really help), this simulator
may be improved if only as a cross check on other implementations. Here are some
items that require attention:
- Detector location
The simulation us using the ACIS-S as the detector and so
there are interchip gaps and curvature. I should really move the ACIS-S around in
the focal plane and use only the events detected by the S3 (?) chip = ACIS-2C chip.
- Source models
Need to add Penning and Be anode.
Well this is always the hang up and incremental progress here
is probably the way to go. Ideally we'd use the MSFC code to create a source file.
Known "satellite" lines on AL and Mg should be included too.