4 June
In the words
of Sara, "We learned an awful
lot until my head split." Sara and Jimmy spent the week reading
about all things related to the mobleam and the three of us brushed up
on our
C++. We have implemented a new noise-blocking routine for WinBeam
to
purge the data of outliers after the sixth sweep. We
also
spent a good deal of time combing through the physics behind the
molbeam.
Dr. Cederberg taught us everything we could ever possibly want to learn
(as far
as we know) about the quadrupole lens, pumps, vacuum gauges, hyperfine
transitions, and quantum numbers.
11 June
We began the
week by debugging our noise blocking
routine for WinBeam. It ought to eliminate the need for the
manual remove
outliers function. Sara and Jimmy spent the week acquainting
themselves
with MathCad and Linefit. Sara began organizing and fitting
the
mass of RbCl data, and Jimmy started in on the RbF data. By
the end
of the summer, they hope to have fit all previously unfit or poorly fit
data. John took a look at the uncertainty calculations in Mike's
Linefit. Because it is fast and general, Mike's
Linefit should
greatly streamline data fitting. In other news, Dr. Engbrecht had
the
neutron source open in the advanced lab open for most of the week, so
we
actually got to see what is inside of it.
17 June
In light of
slowed RbBr progress, Dr. Cederberg
thought it might be nice for us to investigate the spectrum of a new
molecule
and experience the research process from start to finish. We
settled on
KBr because can improve on the precision of coupling constant
values by a
few orders of magnitude and because the analysis of the KBr spectrum
should
prove straightforward compared with that of RbBr. Jimmy fitted a
lot of
RbF lines this week and learned to make MathCad do his bidding.
Sara has
continued collecting and organizing the RbCl data, and she set up the
WinBeam
scan file for our new KBr runs. John fixed the uncertainty
calculations in Mike's Linefit. It now can fit for either common
Stark
amplitudes or separate Stark amplitudes. Tomorrow we have the
first
symposium of the summer research session. As usual, we will
present
a poster.
25 June
Preliminary KBr data looks good. The spectra we observe
differ not insignificantly from our predictions, so we do have room for
improvement in the values of coupling constants. After he
fit the first few KBr data sets, Jimmy tried to run Specfit to generate
improved predictions and to aid fitting. Unfortunately Specfit
refused to converge properly on new parameters. After a long
week of massaging Specfit into operation, Jimmy produced new parameters
yesterday. Sara finished sorting through the RbCl data and has
begun to fit some rather complicated-looking spectra. John has
continued modifying Mike's Linefit. He added the option to
edit the trial parameters manually during the fit process. Some
of this summer's puzzle pieces are finally falling into place!
2 July
The new KBr parameters greatly improved fitting. By now we have
probably made the most important adjustments to KBr coupling constant
values. We may yet finish work on that molecule this
summer. Jimmy "KBr" Randolph has continued collecting data and
grinding out fits. Sara has prepared a bunch of nasty looking
RbCl fits for Specfit this week. John has been debugging.
Check back next week to read about more exciting progress.
9 July
This week
John debugged and tested Linefit code. It is now up and running
and can fit most data sets. Sara finished fitting the
stubborn RbCl data and began coaxing Specfit to converge on new
parameters. She spent a lot of time sifting through
the details of the Mathcad worksheet. Jimmy continued fitting KBr
and RbF data, running Specfit, and writing Mathcad
programs. We are on pace to submit papers on
KBr, RbCl and RbF by the end of the summer!
16 July
We replaced the KBr source and continue to see nice-looking
spectra. In preparation for writing and submitting papers,
Dr. Cederberg taught us about TeX and the molbeam Unix account.
Jimmy has continued fitting the KBr data and running specfit. He
also returned to organizing and fitting the Rbf data. Sara ran
specfit for RbCl all week. She got the chi value of her fit down
to 2.5 or so. John has begun putting the finishing touches on
Linefit. It cranked through a 6LiI
fit with a
total of 45 parameters in under 7 minutes!
23 July
Yesterday we had the annual summer research canoe trip. All three
members of the molbeam group at one point or another participated in
the 7 ship battle-canoe! Everyone returned sopping
wet. This week John put the finishing touches on Linefit
and now is successfully using it to fit the 6LiI spectrum.
Just today Sara managed to improve the chi of her RbCl spectrum fit
down to 2 or so without excluding too many lines from the fit.
Jimmy has begun filling in the gaps in our KBr data with some lines of
higher vibrational and rotational energy to pin down more of the
nuclear parameter values.
30 July
This week Specfit was the name of the game. Sara had
trouble nudging Specfit to converge, so she spent much of her time
reading about the physics and people of molecular spectroscopy.
John fitted the entire LiI spectrum with somewhat encouraging
preliminary results, but he still has a lot of work to do refine the
fit. As always, Jimmy has continued managing KBr and fitting RbF
lines. He still hopes to finish the KBr analysis and possibly the
RbF by the end of the summer.
6 August
Today is the last day of research. We gave a talk at the
symposium and received several compliments. During the last week
Sara has continued working off and on with the RbCl spectrum fit.
She has also read about quantum mechanics, singlet sigma molecules, and
other nifty things. Jimmy ran specfit for RbF this week and
produced a reasonable preliminary fit, and he continued to wrap up
study of KBr. John ran into an unusual frequency shift in the
leading term of the Iodine quadrupole expansion in the 6LiI
fit and will likey need to wait until next year to figure it out.
Check out our summaries on the main page for our final thoughts.