Progress Report from the Mechanical/Shield Group Feb. 26, 2003


* The next meeting is Mar. 12th at 9:30 AM in the To De Determined.
  The following meeting is Mar. 26th at 9:30 AM in the TBD. 

* Shield and Cold Plate Engineering and Integration  
  Clark Reid continues to work on importing the SNAP satellite 
  integration model into Ideas.

  Tom P. found there are a couple of SolidWorks licenses within the T.D.
  that are essentially not used. We will scoop them up and that should 
  get us through the FY.  He also noted that SolidWorks provides a 
  freeware plug-in viewer obtainable at 
  http://www.solidworks.com/swdocs/Support/html/viewer.cfm

  Investigation continues on how to make a materials projection in 3D.

  We reviewed the draft T.D. WPAS and cataloged some initial comments to 
  be sent to Peter.
  
* Shielding Simulation

  Tom D. described the three main sources of ionizing radiation that 
  satellite will encounter: the Van Allen belts, the galactic cosmic rays,
  and the solar proton events. He showed a scaled picture of indicating 
  the SNAP orbit overlaid with Van Allen belts. The slides are available
  in this directory. The filename is diehl_02_26_2003.ppt.
  
  Tom D. promised to check with the electronics guys to see what 
  they are considering using. It turned out that will depend on what dose
  we tell them to expect.  In part that's because the technology that they 
  need for so much storage is new. 

  Fritz Dejongh is working on the Spenvis simulation.  He will find
  Hubble shielding references, if any exist. He reminds us we can do
  a lot with a model that incorporates materials projections, perhaps
  using the full Solidworks model.  He writes: "It appears it would answer 
  almost all the questions in a fairly simple way.  Exceptions might be 
  issues of secondary production, or multiple hard scatters, for which 
  we can use geant or mars, probably with simplified geometries. (He) 
  hopes to find out more on what technique is OK at the collaboration 
  meeting."

  Nikolai noted that there are two time scales to consider for the 
  shielding source term. The first is  1) The time spent in making the image - 
  a few minutes and that is position dependent. The 2nd is the 3 day
  orbit and that is not. One can integrate the source term over an orbit.
  This suggests a strategy for performing the overall shielding 
  calculation. He is heading to D.C. and will ask around for an explicit 
  source term model.