Minutes of the E00-102 Meeting
Thursday, September 5 2002

Fissum

KF/WH/BR/AS/LW

o Kevin and Wendy began by reporting the E00-102 poster 
  generated some interest at the Gordon Conference.

o Bodo then summarized the continuing progress he has made 
  with the optics work, and in particular, with the y_target 
  work.  Recall that we had two surveys of the waterfall 
  target - one taken well before the experiment, and one 
  taken when it ended.  Unfortunately, they differed in 
  the "as found" location of the central waterfoil by 
  something like 3 mm.  The HRSl, with its extreme forward
  angle, was not terribly sensitive to this, but the HRSr
  clearly was.  All the optimization work Bodo did previously
  for the HRSl was based on the first survey.  When he moved 
  to the HRSr, things fell apart.  In the end, he was forced
  to tweak the results for the HRSr "by hand" by about 2 mm 
  (very surprising) for them to make any sense.  He then
  repeated the entire exercise for the HRSr using the second 
  survey results and no tweaking "by hand" was necessary.  
  That is, the survey and reconstruction for the HRSr agree
  to +/- 0.5 mm.  The conclusion is that "something" happened 
  between the time of the first survey and the data taking for 
  the experiment. 

o For consistency, he then repeated the y_target work for the
  HRSl using the second survey.  The survey and reconstruction 
  for the HRSl continue to agree to +/- 0.5 mm.  The angular
  reconstruction continues to be good:  for theta it is +/- 1 
  mrad and for phi it is +/- 0.75 mrad.

o Bodo then tried to analyze the coincidence HRSr optics 
  data.  Recall the idea was to place a tight Emiss cut on
  H(e,ep) coincidence data to reject punchthrough events and 
  hopefully clean up the (theta, phi) spectra enough that
  holes could be seen.  The idea seemed to work, but the
  statistics were too poor to deliver any information on
  anything but the central hole and the central foil.  
  Cuts tighter than +/- 1 MeV destroy the statistical sample.
  Looser cuts result in too much punchthrough being retained.
  Further, the correlations were such that the sieve slit
  required much better overall illumination.  Conclusion:  
  the idea is probably sound, but one needs to count for a lot 
  longer and optimize the phase space overlap between the two 
  spectrometers.  Further, an iterative procedure is probably 
  necessary.  Next time...

o That said, Bodo tried two existing and trusted databases 
  and both produced exactly the same results.  He concluded 
  that we should be fine.  Thus, while dp and Emiss 
  optimization remains to be performed, the first-pass physics 
  analysis can begin!

o Finally, Bodo related the HRSr LVDT saga.  During the 
  experiment, the HRSr LVDT was installed and working.  In 
  order to calibrate it, we needed a survey and the LVDT 
  reading at the time of survey.  Unfortunately, this 
  information has been misplaced.  We thus have no mispointing 
  information from the HRSr LVDT until the reading at the time
  of survey is found.  Does anyone know where it is?  Arun will 
  investigate.  

o All is not lost though.  Wendy has been investigating the
  mispointing.  She presented the react_z reconstruction for
  the surveyed HRSl for the entire experiment in a striplined 
  fashion, and is was very constant (as it should be) to 
  something like the +/- 0.5 mm level.   Thus, we can use the 
  HRSl as a benchmark.  A striplined y_target reconstruction 
  for the HRSr was very discontinuous, which demonstrated that 
  mispointing was a definite issue (although this analysis may
  require some refining).  Anyway, we will use the HRSl as the 
  benchmark, and force the HRSr reconstruction to be what the 
  HRSl says it should be, and extract the mispointing in this 
  fashion.  By then, Arun will hopefully have located the HRSr 
  LVDT readings we need to calibrate them using the survey 
  information, and everything will agree nicely and in a 
  self-consistent fashion.  Larry suggested that an analysis of 
  react_z vs. scattering angle would be interesting, to see if 
  the spectrometer mispointing is a reproducible quantity.

o Kevin concluded by outlining some of the ideas for new 
  experiments in the same vein as this one.  One came from 
  the poster session at the Gordon Conference.  We will meet 
  some time next week informally to discuss whether or not we 
  want to pursue any of them.  If you are interested in 
  participating, send an email and let us know.
  
o Kevin also pointed out that the draft PRC article for the 
  E89-003 project has progressed substantially.  At present, 
  the experiment and analysis sections can be critically 
  proofread.  Please send in your suggestions.  The introduction, 
  results, and discussion are simply smeared over the two PRLs.  
  They are currently being critiqued by Udias, Kelly, and 
  Ryckebusch.  Jan has also provided a new and vastly improved 
  calculation suite for the continuum results, and can demonstrate 
  simultaneous good agreement for the bound states as well.  
  Jan also volunteered to do all the calculations for the 
  dip results we took, so it looks like we will have an appendix
  on the dip in the article.  Hopefully, the critiques will 
  arrive soon, and we can go from there.  The article is not 
  yet ready for general release and critique within the 
  Collaboration, but it is close.  We would like to submit 
  before Xmas this year.  If you would like a copy of the article 
  or the Ryckebusch suite, send Kevin an email.