Turbo and Mechanical Pumps Low Energy End
Turbo & Mechanical Pumps High Energy End
Analyzing Magnet and Beam Lines
Ion Pump, Beam Profile Monitor and HV Steerers
The Pelletron
Our Pelletron is a small tandem electrostatic accelerator (model 3SDH) made by the National Electrostatics Corporation. It operates at a terminal potential of up to 1.1 Megavolts, producing protons of with energies up to 2.2 MeV and alpha particles with energies up to 3.3 MeV. The on-target beams currents typically run to something between 50 and 100 nano-amps. It has been a pretty reliable machine over the years. Typical maintenance usually rebuilding the ion source once a year and replacing the bearings of one of the turbo-molecular pumps (they seem to last about 18 months or so).
The Union College Pelletron Accelerator
To see pictures of the various components of the accelerator, point your mouse over different pieces in the figure below. For a larger image, select the object by clicking the links under the pictures.
Turbo and Mechanical Pumps Low Energy End
Turbo & Mechanical Pumps High Energy End
Analyzing Magnet and Beam Lines
Ion Pump, Beam Profile Monitor and HV Steerers
History
Union College obtained it's first nuclear particle accelerator in about 1965 with a grant from the Atomic Energy Commission. Professors Goble, Schwarz, and Pilcher were instrumental in writing the proposal and getting the machine installed. It was a High Voltage Engineering 400 KeV Van de Graaff machine capable of currents in excess of 100 micro-amperes. The original purpose was to accelerate deuterons into a tritium target, and so produce 14 MeV neutrons. The neutrons were used to study short-half life isotopes.
Professor Christopher Jones took over the machine in about 1970, and focus shifted to other uses such as PIXE (proton induced x-ray emission spectroscopy), elastic scattering, and occasionally channeling and RBS (Rutherford backscattering spectroscopy) studies. We had a lot of fun with that accelerator over the years. Many students did senior projects ranging from the development of auxiliary circuits to channeling to PIXE.
Recognizing the shortcomings of using 400 KeV protons (in particular for PIXE and RBS work), the department decided in about 1990 to acquire a new accelerator. The effort was spearheaded and the proposal was written by David Peak. Some college funds were used to match NSF funds, and so we were successful in getting the new accelerator installed.
We have used this accelerator several ways in recent years. We usually do one experiment in our "modern physics" course. This is often a PIXE experiment, but we have sometime done the "Rutherford" scattering experiment in which the angular distribution of the scattered particles (protons or alpha particles) is measured.
Also, we use the accelerator for two experiments in our junior lab course, Physics 300 as well as in our freshman seminar class, Physics 100. Physics 300 is an experimental techniques class in which the students get a hands-on introduction to both RBS and PIXE. In addition, we have often had students doing senior projects.
Many students elect to do senior research projects using the accelerator. In the past few years the accelerator has been host to a number of environmental physics projects. Alyssa Maloney '05 did her senior thesis on using PIXE to analyze sediment from the Hans Groot's Kill stream that runs through the Union College campus and LLauren Carlson '07did a sophomore scholars project on the Pelletron Particle Accelerator and its application to materials analysis. Alex Kricks '07 investigated the amount of mercury that is present in seafood, particularly swordfish and shark. Currently, Brandon Bartell '10 and Steve Po-Chedley '08 are working on projects using the accelerator. Brandon has written VPython code to convert our spectrum data files to a format suitable for use in our analysis software, GUPIXWIN and has calibrated our accelerator using this software. Steve is working on his senior thesis investigating the downwind radial distribution of heavy elements in the soil and in tree cores that are located near a power plant in western New York State. In addition, Steve is working on a project in Bioremediation in which he will be analyzing samples obtained form selected areas that were ravaged by hurricane Katrina in New Orleans.
In the past couple of years we've had many students working on research projects and making presentations at national conferences. Some of these are highlighted below.
Students Projects
Winter - Spring 2010
Maria Battaglia - Maria's a sophomore Leadership in Medicine student who is working with me on an elemental composition & concentration of liquid precipitation around New York State. We've performed a PIXE analysis of rainwater and snow data collected from Clifton Park, Hadley, Corinth, Schenectady, Cold Spring Harbor, and Oyster Bay, NY using the 1.0 MV tandem electrostatic Pelletron particle accelerator. Maria will be presenting her results at several venues throughout the year. The first will be the April 2010 meeting of the New York State Section of the American Physical Society, follwed by the Union College Steinmetz Symposium, in May, and at the 21st international Conference on the Applications of Accelerators in Research and Industry (CAARI-2010) held in Fort Worth, Texas in August.
Katie & Maria's Poster for the Division of Nuclear Physics meeting in Waikloa, Hawaii.
Fall 2009, Waikoloa Hawaii: Joint Meeting of the Japanese and American Physicsal Societies Nuclear Physics Division in Wakoloa Hawaii, October 12 - 17, 2009 in which Katie, Colin and Chad presented their work over the summer on rainwater and aerosol analysis in Upstate NY.
The last picture on the right is the entire group of us from Union College's Department of Physics & Astronomy that went to the conference. From left to right in the front row: Prof. Rebecca Surman, Ana Mikler, Prof. Scott LaBrake, Chad Herrington, & Katie Schuff. In the back row from left to right: Danny Berringer, Colin Gleason, & Prof. Mike Vineyard.
Summer 2009 Research Students
Katie Schuff - Katie's a rising sophomore Physics/Math double major who is working with me on the elemental composition of rainwater collected from Schenectady's Historic Stockade District and analyzed using the 1.1 MV tandem electrostatic Pelletron particle accelerator.
Colin Gleason - Colin is a rising junior Physics major working with Prof. Mike Vineyard on the elemental analysis of aerosol samples from collected from Schenectady's Historic Stockade District analyzed using the accelerator.
Chad Herrington - Chad is a rising junior Physics/Math double major working with Prof. Mike Vineyard on elemental analysis of aerosol samples from collected from Schenectady's Historic Stockade District analyzed using the accelerator.
Random pictures from the accelerator lab
Katie working hard on Facebook probably. Actually she's working on a method for preparation of the rainwater samples.
Chad, Colin, and Kaite running the accelerator.
Mike, Colin, and Chad watching the charge collection from the beam hitting the sample. Mike is too focused on data collection to notice the camera.
Colin loading another aerosol sample.
Brandon Bartell '10
Brandon's project over the summer was designed to introduce him to how a tandem electrostatic particle accelerator works as well as train him to be an operator on the accelerator. In addition, Brandon's computer programming skills proved to be invaluable. The accelerator lab recently purchased a new software analysis package, called GUPIXWIN. This analysis package had to be able to open and display our PIXE spectrum files taken from our accelerator's data acquisition system. GUPIXWIN has its own file format structure that did not match our spectrum files. Brandon wrote the necessary code in VPython to convert our data acquisition files to GUPIXWIN's format, no easy task, but he accomplished it with ease.
Steve Po-Chedley '08
Steve's senior thesis project is two-fold. First he is using PIXE to investigate the distribution of heavy metals (specifically lead, arsenic and mercury) in tree bark, tree cores, tree leaves and soil samples as a function of the downwind radial distance from a coal power plant located near Buffalo NY. The second project he is working on is the analysis of lead and arsenic contaminant uptake in tree and soil samples used for bioremediation, and these samples are acquired from New Orleans, LA. The trees were planed in the aftermath of hurricane Katrina and will take up heavy metals as part of their life cycle. Tree samples will eventually be taken and analyzed for their heavy metal concentration in order to determine if the bioremediation process is being successful. Steve is currently in Australia on a term-abroad. Have fun Steve!
At the end of the summer Brandon, Steve and I went out fishing hoping to get some samples of (contaminated) fish to run on the particle accelerator. Here's some of the pictures from the trip on the Mohawk River. Needless to say we are still looking for some fish samples to run.
Alex Krickx '07
Alex's project involves the analysis of mercury in seafood. He will be using our 1.1 million volt tandem Pelletron particle accelerator to detect and measure the concentration of mercury found in commonly available seafood, like swordfish. Alex will determine the presence of and concentration of mercury using RBS (Rutherford Backscattering Spectroscopy) and PIXE (Proton Induced X-ray Emission) studies.
Matt Roginski '07
Matt is currently working in the Mechanical Engineering Department under Dr. Andrew Rapoff studying the Bone Density Distribution in the Symphyseal Region of the Anthropoid Mandible Using Quantitative Micro Computed Tomography. Matt's senior thesis involves the use of x rays to generate images of the jawbone of an anthropoid and is a combination of Mechanical Engineering and Physics.
Please visit Matt's webpage on Bone Density Distribution using CT
Luther Vucic '07
Luther's project is on Sonoluminescence, or the production of light using sound waves. The first part of his project deals with the development of an experimental technique and apparatus to see a sonoluminescing bubble. In the next phase Luther will be trying to model the collapsing bubble and investigate the intensity of the light that is produced.