Sadly, tomorrow is the last day of my internship at Jlab. It has been a great experience working here with my mentors Vince, Tim, and other Jlab friends. I'll present my work tomorrow at a poster session with the other SULI and REU students. I made this poster to show the results of my research:
My research paper and abstract will be submitted online tomorrow. My abstract will be published in the DOE's Journal of Undergraduate Research. There's also a chance that I could have my full research paper published there as well.
Underground Tour -- Journey through a particle accelerator
7/10/2008
This week I got a special bonus: a tour through the accelerator facility! The accelerator is off for a few weeks while new experiments are being setup, so all the SULI interns got to take a tour of the control center, injector system, Hall A, Hall B, and the north LINAC (linear accelerator). I was prepared this time and brought along a video camera! I'll have some nicely edited inside footage posted soon. Until then, here's a nice promotional video (made by JLab) that gives an overview of what JLab does:
I've made some good progress this week, by completing two of the four simulations I need to run. I finished running my simpler simulation on statistical error with prescaled data about a week back. I have now also completed running a FORTRAN simulation of the E97-110 experiment which includes a prescaling effect. This code also simulates the spectrometer acceptance cuts. So far, it looks like both of these simulations follow Dr. Robert Feuerbach's model (described below).
Its already a few weeks into my
research, so I've made some good progress. So far I've learned some
C++, ROOT/ANALYZER, Perl, and Fortran for my projects; all good languages too know for
this field. I've been glad to see many people at Jlab using Linux
distributions (probably typical of a physics research environment). The
standard here is Redhat, but I usually jump between Ubuntu/XP/Vista on
my laptop and home desktop.
I'm currently
working on two projects separately that I also plan to combine soon
(I'll get a bit specific here). The Continuous Electron
Beam Accelerator Facility at Jefferson Lab scatters electrons from
various targets to study the structure of nuclear particles. In Hall A,
experiment E97-110 [1] scattered polarized electrons from a glass cell
filled with polarized 3He. For this experiment, measurements were made to examine the spin structure of nucleons at low Q2
as a test of the theoretical predictions of the generalized GDH sum
rule. In this experiment, collimators were strategically placed to
block electrons that scatter from the windows of the target cell.
Unfortunately, electrons scattering from within the target cell may
penetrate the collimators and be refracted into the detector
acceptance, thereby introducing an additional background. I plan to
conduct a two phase analysis of this background and the consequent
statistical error. First, cuts on the collimator location will be
reversed in order to determine the background asymmetry. Second, a
Monte Carlo will be implemented to simulate background from the events
which penetrate the collimators. The systematic error resulting is to
be determined from this analysis.
My other project involves a similar Monte Carlo method. Trigger prescaling is one method to control the deadtime of data
acquisition. If the trigger rate is too high for a detector system,
then this method effectively limits the electronics to consider only
every Pth incident event. This allows the trigger rate to be lowered as needed. The prescale factor P as well as the acceptance factor f
contribute additional statistical error to detection of particles. I
used a Monte Carlo method to simulate counting particles and to
determine the statistical error on the measurement. Simulated data can
then be compared to suggested models for error. It can be shown that
this simulation supports Dr. Feuerbach's model [2] for this scenario.
I'll
need to write a research paper and make a poster soon, so I'll have to
start writing up more on my project soon. If anyone's interested in
learning more on these subjects, I'm:
Hi, I'm Ron Pandolfi, a physics & mathematics major and rising senior at R-MC. For the summer, I'm working in a paid internship at Jefferson Lab as part of the SULI program. Jefferson Lab is a national particle accelerator laboratory in Newport News, Virginia.
The
CEBAF (Continuous Electron Beam Accelerator Facility) accelerator at
Jefferson Lab accelerates electrons around a racetrack shaped
underground tunnel then scatters them from various targets. The beam of
electrons is split at the end into three halls. The interactions that
result in the halls are carefully studied in order to learn more about subatomic
particles, like quarks and gluons.
A sky-view of the underground CEBAF accelerator. Electrons are injected at the Electron Source and the linacs accelerate the electron beam.
I'm working with Hall A, analyzing data from the collisions of polarized electrons and polarized Helium (3He)
from a past experiment (E97-110). Its already the fourth week of my
internship at Jefferson Lab, so I've already made good progress in my
research.
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