Status of IMS at GSFC

1
Status of IMS at GSFC

• By Ed Sittler
• CAPS Team Meeting 28
• Marseille, France
• July 26-28, 2004

2
List of GSFC CAPS Team Members

• Ed Sittler
• Don Glenn
• Kevin Edwards
• Sarabjit Bakshi
• David Simpson
• Richard Hartle
• Mark Shappirio
• Dennis Chornay
• Tom Vollmer

3
List of Ongoing Completed Tasks

• Calibration of IMS Prototype
• Ion Beam Measurements at GSFC Cal Facility
  Completed Feb. 04
• Energy coverage 64 eV to 15 keV (Vpa -14.6 kV)
• Ions Measured H,H2, He,C,N,O,H2O, Ne,
  Ar, O2,CO,CO2, C2H2,C2H4,C2H6,N2
• Data stored in Excel Spreadsheets
• Analysis of Cal data using Logistic Power Peak
  Function of all measured species for E ? 15 keV.
  Completed March 04.
• Analysis only includes major fragments (I.e.,
  Neutral, negative, positive peaks). All ghost
  peaks and tail deferred for later analysis.
• Peak Fit Software used for Analysis. Results
  stored in Excel spreadsheet.
• Gaussian-Lorenzian should yield better fits.
  Parametric studies easier. Deferred for later
  analysis.
• A0 Probability of Fragment, A1 Peak Center,
  A2 Peak Width, A3 Peak asymmetry. A2 gt 0
  asymmetric to larger TOF. A2 lt 0 asymmetric to
  shorter TOF. A3 ? 1. If A3 1 peak symmetric and
  A2 sign undetermined.

4
List of Ongoing Completed Tasks(continued)

• Analysis of Modeled Line Profile Functions.
  April-May 04
• Determine energy dependence of line profile
  parameters.
• Allows one to extend line profile parameters to E
  gt 15 keV.
• Used combination of different data sets to
  measure energy dependence of ion fragments over a
  wide range of energies. This is especially
  applicable to LEF data. Allowed us to do ions not
  measured.
• Assumed molecules immediately broke up when
  entering c-foil
• Found determination of mass dependence of peaks
  misleading.
• Diatomic molecules/more complex observe up to 50
  kV for LEF.
• Determined probabilities of different fragments.
• Normalized peaks to unity. ?Pi 1.0. Pi A0i.
• Used combination of different ions to do ions we
  have no data.
• Used FM data to help in their computation for E gt
  15 kV.
• Used extrapolations to higher energies to compute
  parameters for higher charged state ions such as
  He and O.
• Results used to make group tables.
• Results need to be documented in word file.
  Parameters in Excel file.

5
List of Ongoing Completed Tasks(continued)

• Ion beam measurements of prototype at GSFC High
  Energy Facility.
• Extend energy of calibration from 15 kV to 50 kV.
  (Vpa -14.6 kV).
• Ions Measured H,H2, He,C,N,O,H2O, Ne,
  Ar, O2,CO,CO2, C2H2,C2H4,C2H6,N2.
• Measurements should be completed this week. July
  04.
• Data stored in Excel Spreadsheets.
• We will then repeat analysis done for E ? 15 kV.
  This analysis will be used to make comparisons
  with our previous extrapolations. The end result
  will be revised group tables at higher energies.
• Results of analysis will be stored in Excel
  Spreadsheets.
• Need to make comparisons with FM cal data and FM
  Flight Data.
• Sources are SwRI, LANL, Earth Flyby, Solar Wind,
  Jupiter Saturn
• Routine written that will interpolate in energy
  and return peak parameters for all ion species
  and their fragments. Used for Group Table
  Generation.
• Developing IMS Simulator. Includes rate dependent
  effects. In hold.

6
List of Ongoing Completed Tasks(continued)

• Flight Software Development
• SAM Group Table Generation
• Test plans developed. Used simulations from
  Sittler et al. (2004) paper. April 04.
• Computed simulated spectra.
• Computed binning intervals and inverse-coupling
  coefficients.
• Converted simulations into TDC simulator files.
  Fed into EM System.
• Produced data products
• Wrote simulator code to simulate quick-look
  displays. Compared with output of EM System and
  Flight Software. Results documented.
• With results of prototype calibration and its
  analysis generated Group Tables for SOI, Inner
  Magnetosphere, Titan Torus and Solar Wind.
• Tested all Group Tables. Repeated above
  procedures and test plans.
• Delivered Group Tables to SwRI. May 04.

7
List of Ongoing Completed Tasks(continued)

• Hardware Binning versus Software Binning.
• Present version of hardware binning too slow.
• Revised version will be very fast and allow one
  to handle more complex situations. 15 ion
  sub-groups possible.
• Will be more accurate.
• In order for software binning to run fast enough
  must collapse data by factor of 4 for ST and
  factor of 2 for LEF.
• Use full 2048 channel capability.
• Binning intervals can have wider widths and still
  run fast.
• Multiple binning intervals now possible. Increase
  accuracy and improve statistics. (I.e., bin on O0
  and O- peaks).
• Other flight software issues being worked on as
  time allows.
• Support operations, which includes present
  analysis of SOI data.

8
List of Ongoing Completed Tasks(continued)

• Analysis of SOI Data.
• Developed read routines so we can read level0
  data products in order to evaluate performance of
  flight software, SAM Algorithm, Group Tables,
  Quality of Data Products and Comparison with
  level2 data products.
• SwRI to provide level2 data product read
  routines.
• Concentrating on June 30 1800 to 2400 hours
  data.
• We have ability to analyze all IMS data products.
• TOF Spectrograms for internal analysis of data.
• Ion data products. Evaluate performance of SAM.
• Statistical fluctuations cause water group ions
  to anti-correlate.
• Summing of water group ions removes this
  structure. Nice energy plots.
• Have capability to deal with C-kernels, S/C
  orientation/actuator angle.
• Can perform pitch angle analysis of data.
  Presently use Connerney Model.
• Can perform trajectory plots and field line
  mapping.
• Presently developing algorithm to perform
  non-linear fits to TOF data.
• Analysis gives relative abundance of ion species
  investigate ion shifts.
• Determine ion composition.

9
List of Ongoing Completed Tasks(continued)

• Developed script routine to capture more data.
• RTIU? problem is causing us to throw out a
  majority of the data.
• Present routine has problems and some bad data
  not excluded.
• Will continue to work problem.
• Developing algorithm that will re-construct ion
  counts from ion data for previously determined
  ion peak shifts and other calibration
  determinations from analysis of TOF data.
  Algorithm requires high rate data (4,8,16 kbps)
• With revised cal data compute ion data products
  for all combinations of ion counts, energies and
  presently used Group Tables.
• Then using a multi-dimensional interpolation
  routine compute the reconstructed ion counts from
  the measured ion counts using a non-linear
  fitting algorithm. The first step will make
  algorithm fast.
• This algorithm should provide more reliable
  composition results.
• Once the above completed will be able to compute
  fluid parameters for various ion species.
• The results of the above analysis will allow us
  to make more accurate group tables.