Fabrication of silicon-based optical components for an ultraclean accelerator mass spectronomy negative ion source

Fabrication of silicon-based optical components for an ultraclean accelerator mass spectronomy negative ion source

Date: May 1994
Creator: Kirchhoff, J. F.; Marble, D. K.; Weathers, Duncan L.; McDaniel, Floyd Del. (Floyd Delbert), 1942-; Matteson, Samuel E.; Anthony, J. M. et al.
Description: This article discusses an ultraclean accelerator mass spectronomy negative ion source for semiconductor material mass analysis that was built and is in operation at the University of North Texas' Ion Beam Modification and Analysis Laboratory (IBMAL).
Contributing Partner: UNT College of Arts and Sciences
Trace Element Analysis of Mineral Water Samples through XRF and ICP-MS

Trace Element Analysis of Mineral Water Samples through XRF and ICP-MS

Date: April 19, 2012
Creator: Dash, Akshar; Thurber, Casey; Kummari, Venkata C.; Verbeck, Guido F.; Duggan, Jerome L. & Rout, Bibhudutta
Description: Poster on a trace element analysis of mineral water samples through XRF and ICP-MS.
Contributing Partner: UNT Honors College
High sensitivity measurement of implanted As in the presence of Ge in Ge(x)Si(1-x)/Si layered alloys using trace element accelerator mass spectrometry

High sensitivity measurement of implanted As in the presence of Ge in Ge(x)Si(1-x)/Si layered alloys using trace element accelerator mass spectrometry

Date: December 11, 2000
Creator: Datar, Sameer A.; Wu, Liying; Guo, Baonian N.; Nigam, Mohit; Necsoiu, Daniela; Zhai, Y. J. et al.
Description: This article discusses high sensitivity measurement of implanted As in the presence of Ge in Ge(x)Si(1-x)/Si layered alloys using trace element accelerator mass spectrometry.
Contributing Partner: UNT College of Arts and Sciences
Low-level copper concentration measurements in silicon wafers using trace-element accelerator mass spectrometry

Low-level copper concentration measurements in silicon wafers using trace-element accelerator mass spectrometry

Date: June 8, 1998
Creator: McDaniel, Floyd Del. (Floyd Delbert), 1942-; Datar, Sameer A.; Guo, Baonian N.; Renfrow, Steve N.; Anthony, J. M. & Zhao, Z. Y.
Description: This article discusses low-level copper concentration measurements in silicon wafers using trace-element accelerator mass spectrometry.
Contributing Partner: UNT College of Arts and Sciences
Z1 oscillations of the mean charge for isotachic ions in carbon foils

Z1 oscillations of the mean charge for isotachic ions in carbon foils

Date: April 1995
Creator: Arrale, A. M.; Jin, Jianyue; Zhao, Z. Y.; Weathers, Duncan L.; McDaniel, Floyd Del. (Floyd Delbert), 1942- & Matteson, Samuel E.
Description: This article discusses Z1 oscillations of the mean charge for isotachic ions in carbon foils.
Contributing Partner: UNT College of Arts and Sciences
Simultaneous measurement of the average ion-induced electron emission yield and the mean charge for isotachic ions in carbon foils

Simultaneous measurement of the average ion-induced electron emission yield and the mean charge for isotachic ions in carbon foils

Date: February 1997
Creator: Arrale, A. M.; Zhao, Z. Y.; Kirchhoff, J. F.; Weathers, Duncan L.; McDaniel, Floyd Del. (Floyd Delbert), 1942- & Matteson, Samuel E.
Description: This article discusses simultaneous measurement of the average ion-induced electron emission yield and the mean charge for isotachic ions in carbon foils. Knowledge of the incident ion's atomic number (Z₁) dependence of ion-induced electron emission yields can be the basis for a general understanding of ion-atom interaction phenomena and, in particular, for the design of Z₁-sensitive detectors that could be useful, for example, in the separation of isobars in accelerator mass spectrometry.
Contributing Partner: UNT College of Arts and Sciences
Experimental evidence for a discrete transition to channeling for 1.0-MeV protons in Si〈100〉

Experimental evidence for a discrete transition to channeling for 1.0-MeV protons in Si〈100〉

Date: April 1998
Creator: Zhao, Z. Y.; Arrale, A. M.; Li, S. L.; Marble, D. K.; Weathers, Duncan L.; Matteson, Samuel E. et al.
Description: This article discusses experimental evidence for a discrete transition to channeling for 1.0-MeV protons in Si〈100〉.
Contributing Partner: UNT College of Arts and Sciences
The stopping of energetic Si, P and S ions in Ni, Cu, Ge and GaAs targets.

The stopping of energetic Si, P and S ions in Ni, Cu, Ge and GaAs targets.

Access: Use of this item is restricted to the UNT Community.
Date: December 2001
Creator: Nigam, Mohit
Description: Accurate knowledge of stopping powers is essential for these for quantitative analysis and surface characterization of thin films using ion beam analysis (IBA). These values are also of interest in radiobiology and radiotherapy, and in ion- implantation technology where shrinking feature sizes puts high demands on the accuracy of range calculations. A theory that predicts stopping powers and ranges for all projectile-target combinations is needed. The most important database used to report the stopping powers is the SRIM/TRIM program developed by Ziegler and coworkers. However, other researchers report that at times, these values differ significantly from experimental values. In this study the stopping powers of Si, P and S ions have been measured in Ni, Cu, Ge and GaAs absorbers in the energy range ~ 2-10 MeV. For elemental films of Ni, Cu and Ge, the stopping of heavy ions was measured using a novel ERD (Elastic Recoil Detection) based technique. In which an elastically recoiled lighter atom is used to indirectly measure the energy of the incoming heavy ion using a surface barrier detector. In this way it was possible to reduce the damage and to improve the FWHM of the detector. The results were compared to SRIM-2000 predictions ...
Contributing Partner: UNT Libraries
Leaf elemental analysis and growth characteristics of mycorrhizal treated post oak seedlings via particle induced X-ray emission spectroscopy.

Leaf elemental analysis and growth characteristics of mycorrhizal treated post oak seedlings via particle induced X-ray emission spectroscopy.

Date: May 2006
Creator: Boling, Blake C.
Description: Growth and element assimilation was investigated in post oak seedlings exposed to four different treatment combinations of fertilization and ectomycorrhizal inoculation. Element concentration in excised leaves was analyzed via particle induced X-ray emission spectrometry with a 1.8 MeV proton macrobeam. Mean growth was significantly different across the treatment groups as well as mean concentration of Mg, Al, S, K, Ca, Fe, Cu, and Zn. The data suggest that fertilization rather than mycorrhizal inoculation had a stronger influence on plant growth and nutrient uptake. A follow up study was conducted with a 3 MeV microbeam. A 850 μm2 scanned area of a post oak leaf produced topographical maps of 11 elements.
Contributing Partner: UNT Libraries
K-shell x-ray-production cross sections in 6C, 8O, 9F, 11Na, 12Mg, and 13Al, by 0.75- to 4.5-MeV protons

K-shell x-ray-production cross sections in 6C, 8O, 9F, 11Na, 12Mg, and 13Al, by 0.75- to 4.5-MeV protons

Date: November 1, 1991
Creator: Yu, Y. C.; McNeir, M. R.; Weathers, Duncan L.; Duggan, Jerome L.; McDaniel, Floyd Del. (Floyd Delbert), 1942- & Lapicki, Gregory
Description: This article discusses K-shell x-ray-production cross sections. Abstract: K-shell x-ray-production cross sections are reported for elements with K-shell x-ray energies between 277 eV (C) and 1487 eV (Al). The x-ray measurements were made with a windowless Si(Li) detector that was calibrated for efficiency by comparing bremsstrahlung spectra from electron bombardment of thin foils of aluminum, silver, and gold with theoretically determined bremsstrahlung spectral distributions. The x-ray-production cross-section measurements are compared to first-order Born and perturbed-stationary-state with energy-loss, Coulomb deflection, and relativistic corrections (ECPSSR) ionization theories using single-hole fluorescence yields. The ECPSSR and first-order Born theoretical predictions are, in general, in close agreement with each other and both generally fit the data quite well.
Contributing Partner: UNT College of Arts and Sciences
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