Dr. Andy Hollerman Dr. and Mrs. Sammie W. Cosper/BORSF Endowed Associate Professor of Physics Associate Director, Louisiana Accelerator Center University of Louisiana at Lafayette Lafayette, Louisiana 70504 [email protected]Louisiana Accelerator Center Spring 2013
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Dr. Andy HollermanDr. and Mrs. Sammie W. Cosper/BORSF Endowed
Associate Professor of PhysicsAssociate Director, Louisiana Accelerator Center
University of Louisiana at LafayetteLafayette, Louisiana [email protected]
Louisiana Accelerator Center
Spring 2013
Agenda
• Overview and History• Facilities• LAC Research Examples
– Micromachining– Solar Sails– Half Brightness Fluence
• Conclusions• Contact Information
Overview and History
OverviewThe Louisiana Accelerator Center (LAC) at the University of Louisiana at Lafayette (UL Lafayette) is recognized as a Research Center by the Louisiana Board of Regents (BOR) with active programs emphasizing materials analysis, microfabrication and high energy focused ion beam physics.
Location
• LAC (A on map) is located at 320 Cajundome Boulevard and is across the street from the Cajundome and Cajun Field in Lafayette, Louisiana.
• It can be accessed by auto from Reinhardt drive.
Early History• LAC had its beginnings in the mid 1970’s when the University of Southwestern
Louisiana (USL, now UL Lafayette) made two surplus property acquisitions:- The first acquisition, a High Voltage engineering Corporation Model KN 3 MV
Van de Graaff accelerator system valued at about one million dollars, was obtained from the NASA's Johnson Space Flight Center in Houston, Texas.
- The second acquisition, the complete contents of a machine shop and a metrology shop, were acquired from NASA's Michoud fabrication facility in New Orleans.
- The moving costs for bringing this equipment to campus was minimal because it was accomplished by physics faculty and staff.
• In 1976, a 4,000 ft2 bare metal building was constructed on Reinhardt Drive, then Souvenir Gate, on a piece of university property used to graze cattle.
• The KN accelerator was installed and made operational for low energy protons and a shop established using the Michoud equipment and additional equipment provided by the offices of the Quality Machine and Pipe Company, currently the Quality Machine Shop, Incorporated.
• In 1981 a shielded accelerator building was constructed at a cost of $680,000 and joined with the existing metal structure.
Later History• The KN accelerator was moved into the shielded structure and the machine shop
moved into the accelerator's former location. • A High Voltage Engineering Corporation Model JN 1 MV Van de Graaff accelerator
system was obtained in 1982 from the University of Virginia, installed in the target room and used as an instructional tool for students.
• In 1985, with the initiation of the Louisiana Quality Support Fund (LEQSF), a plan was developed by the research staff to establish a complete ion beam research facility.
• By 1990, two LEQSF grants were obtained to acquire a high-energy accelerator and an analysis chamber with associated detectors.
• This new accelerator was installed in the site originally occupied by the KN accelerator, which was sold at auction in November 2000.
• In 1997, an ion microprobe system was funded by LEQSF and became operational in 2001.
• In 2003, funding was obtained to acquire an additional set of triplet lenses and a JEOL 6460LV scanning electron microscope to be added to the present microprobe system for the development of a unique (patented) sextuplet focusing system for high-energy ions.
• Since 1990, funding at LAC for ion beam research and related equipment has exceeded $6.3 million.
Sources of Ionizing Radiation
• Natural:- Background radioactive materials on Earth- Space radiation from all non-Earth sources
• Anthropogenic:- Medical applications- Industrial applications- Radioactive contamination (includes
atmospheric testing and accidents)Facilities
LAC Vault Diagram
LAC Pelletron Accelerator
1.7 MV 5SDH-2 Tandem Pelletron AcceleratorNational Electrostatics Corporation
Pelletron Charging System
LAC Negative Ion Sources
RF Charge ExchangeSource
Source of Negative Ions by Cesium Sputtering (SNICS II)
DuoplasmatronPicture of the LAC Sourcea
LAC BeamsSource Available Beams
RF Protons and alpha particles
SNICS IIProtons and elements from solid
sputter cathodes like Li, B, C, F, N, O, Ti, Ni, Cr, Co, Zn, Mo, Al, Eu, and Au.
Duoplasmatron Protons
LAC Beamlines
Analysis
HEFIB
Implant
Beamline Images
High Energy Implant andAnalysis Chamber
High Energy Analysis Chamber
1.7 MV 5SDH-2 Pelletron
Proton Beam Spot
HEFIB SystemMounted Samples
Samples and Measurements
PIXE/RBS Chamber at theLouisiana Accelerator Center
Mounted Samples inPIXE/RBS Chamber
ZnS:Mn TL Excitedby 3 MeV Protons
Irradiated Spots ShowingProton Damage
ZnS:Mn in PPMS Paint PPMS Paint(Proton Dose ~ 1015 mm-2)
UVLight
LAC CapabilitiesTechnique Type
(A/M)*Energy (MeV) Particle Current Beam
Size Application
Rutherford Backscattering Spectrometry (RBS) A 1 - 3 He < 100 nA ~1 mm Elemental and thin film analysis
Channeling (RBS) A 1 - 3 He < 50 nA ~1 mm Structure analysis and light element detection in crystals
Micro-RBS A 1 - 3 He < 1 nA 1 - 100 µm Position sensitive elemental analysis
Particle InducedX-Ray Emission (PIXE) A 1 - 3 H < 1 µA ~1 mm Trace elemental analysis
In-Air PIXE A 1 - 3 H < 1 µA 1 - 5 mm Trace elemental analysis
Micro-PIXE A 1 - 3 H < 500 pA 1 - 100 µm Position sensitive trace elemental analysis
Scanning Transmission Ion Microscopy (STIM) A 1 - 3 H & He < 1 nA 1 - 100 µm Analyze structure of thin
samples using transmitted ions
Nuclear Reaction Analysis (NRA) A Variable Variable
ions 1 - 10 µA 1 – 3 mm Enhanced sensitivity to selected elements
Ion Research Implantation and Irradiation M 1 - 10 All ion
Micromachining M 1 - 3 H < 1 nA 1 - 50 µm Machining small complex shapes using a scanned beam (no mask)
* A = Analysis M = Modification
Analysis Accuracy and Sensitivity
Analysis Technique Acronym Detected
Elements Sensitivity Accuracy
Rutherford Backscattering Spectrometry
RBS Be to U Bulk: 10-4
Surface: 1 to 10-4Composition: < 1%
Layer Thickness: 5%
ParticleInduced X-ray
EmissionPIXE Na to U 10-6 (ppm) 10%
Nuclear Reaction Analysis NRA H to Al 10-2 to 10-6 10%
Other Capabilities• The HEFIB beam line is equipped with a liquid nitrogen-cooled standard x-ray detector
(Princeton Gamma Tech), and a Peltier-cooled Bruker Quantax EDS detector:– The HEFIB system can produce a 1 x 1 µm beam with high-resolution images of tested
materials.• Recently, the center implantation beam line was modified to allow analysis of biological
materials or other delicate samples in ambient conditions using techniques such as in-air PIXE:– A thin titanium window was added to the output port of the implantation chamber allowing
for the beam to be brought out into the air.• The accelerator vault further contains a bench with appropriate optical and digital microscopes
as well as a JEOL model 6460LV scanning electron microscope.• A small library and computer access area is also located in a separate room adjacent to the
accelerator control station.• A metal vapor deposition chamber, small Carver press, and a fully equipped machine shop are
also located in the metal support building.• The shop contains several metal saws, a micro-lathe, an industrial-sized lathe, a mill, and
several pieces of welding equipment.• The shop is also fairly well equipped for electronics work (soldering, testing, and assembly of
prototypes). • A separate chemistry lab houses a fume hood, spin-coater (for analyses of e.g., powdered
material or suspensions), a micro-saw for cutting of crystals and ceramics, a sputter coater and related items, plus two high temperature ovens and a heated incubator.
• In addition, most regular wet-lab items (pipettes, chemicals, glassware, refrigerator etc.) are also available.
LAC Research Examples
LAC Microlithography and Micromachining
µPIXE Solar Sail Analyais
Aluminum Kα Sulfur Kα
Phosphorus Kα Silicon Kα
• 1,000 x 1,000 µm microprobe PIXE scans of a Mylar solar sail material provided by MSFC.
• Analysis completed at LAC using a 2 MeV proton beam with a current of less than 100 pA.
• These scans show Kα x-rays from aluminum, sulfur, phosphorus, and silicon.
• Scan regions that are black correspond to high x-ray yield.
• Areas that are white correspond to no x-ray yield.
• Shades of gray correspond to intermediate yield values.
• Data clearly shows the outline of a bundle of Kevlar threads (500 µm thick) that is glued to the back of the aluminized Mylar sail material.
• This analysis appears to show the glue used to attach the Kevlar fiber bundles to the aluminized Mylar sail material contained sulfur, phosphorus, and silicon.
• W.A Hollerman, T.L. Stanaland, D. Edwards, P. Boudreaux, L. Elberson, J. Fontenot, E. Gates, R. Greco, M. McBride, and A. Woodward, Accelerator-Based PIXE and STIM Analysis of Candidate Solar Sail Materials, 17th International Conference on the Application of Accelerators in Research & Industry, Edited by J.L. Duggan and I.L. Morgan, American Institute of Physics, 452-455 (2003).
STIM Solar Sail Analyais
• 1,000 x 1,000 µm microprobe STIM scans of a Mylar solar sail material provided by MSFC.• Analysis completed at LAC using a 2 MeV proton beam with a current of less than 100 pA.• Regions in each scan that are black correspond to large numbers of detected scattered protons. • Areas that are white in the scan correspond to no detected particles.• Shades of gray correspond to intermediate quantities of detected protons.• The numbers on top of each image correspond to the STIM scan number as displayed by the data
acquisition computer.• This analysis appears to show the Kevlar bundle is cylindrical in shape.• W.A Hollerman, T.L. Stanaland, D. Edwards, P. Boudreaux, L. Elberson, J. Fontenot, E. Gates, R.
Greco, M. McBride, and A. Woodward, Accelerator-Based PIXE and STIM Analysis of Candidate Solar Sail Materials, 17th International Conference on the Application of Accelerators in Research & Industry, Edited by J.L. Duggan and I.L. Morgan, American Institute of Physics, 452-455 (2003).
Data Acquisition System
• LabVIEW graphical environment• Written in the G programming language• Acquisition and data analysis software• Two analog inputs to computer