Michael Squillante - Academia.edu (original) (raw)

Papers by Michael Squillante

2021 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)

This research investigated a new spray pyrolysis technique for depositing cost effective, thin fi... more This research investigated a new spray pyrolysis technique for depositing cost effective, thin films of CuInSe/sub 2/ for terrestrial solar cell applications. This process is attractive because of its inherent simplicity which has permitted large scale production of high quality, thin films at low cost of a variety of materials. This program was directed at determining the chemical and physical conditions required to produce high quality films and at characterizing and understanding the properties of the films produced. During this research effort, we investigated the spray solution chemistry, the deposition parameters, the film properties, and the characteristics of solar cell devices fabricated using the sprayed films. The results are very encouraging but further work is needed to fully examine the use of this unique deposition process in the manufacturing of CuInSe/sub 2/ solar cells.

Research was conducted with the goal of demonstrating the feasibility of designing a novel nondes... more Research was conducted with the goal of demonstrating the feasibility of designing a novel nondestructive, radiometric instrument to accurately quantify the levels of iron, titanium, and other metals in circulating lubricating media at the tens of parts-per-million (ppm) concentration level. The laboratory apparatus for conducting the research was straightforward and consisted of a vertical cylindrical tube with x-ray transparent ends, a radioactive source at one end of the tube, a detector and associated electronics at the other end, and a multichannel analyzer. The tube was repetitively filled to various levels by lubricating media containing various minute amounts of iron on titanium. The data were acquired and analyzed for the direct purpose of determining the ultimate sensitivity. Researchers found that the instrument could detect 10 ppm of iron and 15 ppm of titanium concentration levels in the lubricating medium once the experimental setup was optimized.

MRS Proceedings, 1982

ABSTRACTRecent developments on HgI2 detectors fabricated from platelets grown by the Polymer Cont... more ABSTRACTRecent developments on HgI2 detectors fabricated from platelets grown by the Polymer Controller Growth (PCG) technique have resulted in a better understanding of this remarkable process and provide increased hope for the future of room temperature operable, high resolution x-ray detectors. The benefits of PCG are higher purity using reagent grade materials, better control of stoichiometry, rapid growth, and simplified fabrication. This latter benefit is even more significant when the extreme fragility of HgI2 crystals is considered. The problems of device resolution crystal stability and uniformity, and control ot platelet growth were investigated under a NASA funded program. HgI2 devices fabricated from PCG platelets gave room temperature energy resolutions under 400 eV (FWHM) for the 5.9 eV Mn x-ray. Models for the polymer assisted transport are discussed along with an analysis of spectra obtained from PCG grown devices. Reproducibility has been demonstrated both for plate...

2006 IEEE Nuclear Science Symposium Conference Record, 2006

MRS Proceedings, 1997

Single crystals of InI (Eg = 2.01 eV at 300K) have been grown by vertical Bridgman technique usin... more Single crystals of InI (Eg = 2.01 eV at 300K) have been grown by vertical Bridgman technique using zone refined (ZR) starting materials. The quality of the grown crystal has been evaluated by X-ray diffraction (XRD), Electron probe microanalysis (EPMA) and Photoelectron spectroscopy (XPS). Chemically etched crystal wafer has been used to fabricate optical and nuclear detectors. The results are presented in this paper.

MRS Proceedings, 1982

ABSTRACTSilicon avalanche photodiodes have recently been shown to be a potential replacement for ... more ABSTRACTSilicon avalanche photodiodes have recently been shown to be a potential replacement for vacuum tube photomultipliers in many nuclear scintillation detector applications. The large active area, low noise, and ease of use of these solid-state photomultipliers makes them ideally suited to scintillation detector applications where overall size and ruggedness are a major concern. Historically, avalanche photodiodes have been limited for use in this capacity by small active areas, low internal gains, and poor optical sensitivity at the wavelengths at which most solid scintillator materials emit. Recent advances as the result of research aimed directly at the solution to these problems however, have successfully demonstrated one inch active area silicon avalanche photodiodes which produce a FWHM resolution of 9.5% for Cs137 at room temperature when coupled to a 1″ × 1″ NaI(Tl) scintillation crystal. Improvements to both material quality and device structure have advanced the state...

Radiology, 1991

An automatic exposure controller has been designed that controls the optical film density for fil... more An automatic exposure controller has been designed that controls the optical film density for film, screen, and radiographic techniques typically used in mammography to within 0.05 over a range of 1.3-6.7-cm thickness of Lucite. This degree of accuracy is better than that reported for presently available controllers. The detector system consists of four cadmium telluride detectors and involves the use of a control algorithm to read the detectors and turn off the mammography unit at the correct time. This algorithm is implemented by a microprocessor, which also provides the means for a convenient calibration.

MRS Proceedings, 1999

ABSTRACTThe fabrication and testing of screen printed dye-sensitized large solar cell (15 cm × 15... more ABSTRACTThe fabrication and testing of screen printed dye-sensitized large solar cell (15 cm × 15 cm) based on nanocrystalline TiO2 is described. It is the largest photo-electrochemical (PEC) cell that is based on the dye sensitization of thin (8-18 μm) films of TiO2 nanoparticles in contact with a non-aqueous liquid electrolyte. The cell has the potential to be a low cost, commercial, environmentally friendly, photovoltaic option. Surface as well as electrical characterization, of the nanostructured PEC cells have been performed. The efficiency of these large commercial cells are compared to the laboratory-made small PEC cells. Key words: Photoelectrochemical, solar cells, nanocrystalline, dye-sensitized

Radiation Detectors: Systems and Applications XV, 2014

ABSTRACT Numerous instruments have been developed for performing gamma-ray imaging and neutron im... more ABSTRACT Numerous instruments have been developed for performing gamma-ray imaging and neutron imaging for research, nondestructive testing, medicine and national security. However, none are capable of imaging gamma-rays and neutrons simultaneously while also discriminating gamma-rays from the neutron. This paper will describe recent experimental results obtained using a gamma/neutron camera based on Cs2LiYCl6:Ce (CLYC) scintillation crystals, which can discriminate gamma-rays from neutrons. The ability to do this while also having good energy resolution provides a powerful capability for detecting and identifying shielded special nuclear materials for security applications. Also discussed are results obtained using a LaBr3 scintillation crystal.

IEEE Nuclear Science Symposium Conference Record, 2012

ABSTRACT RadCam™ is a detection system developed by RMD for gamma ray imaging. The system images ... more ABSTRACT RadCam™ is a detection system developed by RMD for gamma ray imaging. The system images and tracks radiation contamination and its distribution. The current system is based on a CsI:Na scintillator coupled to a position-sensitive photomultiplier tube (PS-PMT). The image is obtained either using MURA coded aperture or pin-hole masks. Detected signals are decoded to produce radiation distribution that is overlaid on an image from a video camera (real-time). Due to increased focus on neutron detection, we recently started upgrading the system with a new scintillating material capable of simultaneous gamma ray and neutron detection - Cs2LiYCl6 (CLYC). Due to excellent pulse-shape discrimination, CLYC provides dual-mode detection of gamma-rays and neutrons while cleanly separating the signals from these two types of radiation. In addition, CLYC delivers better energy resolution than classical scintillators, such as CsI:Na. In this paper we present our initial results obtained with a system in which the original CsI:Na crystal was replaced with a CLYC scintillator.

The program reported has examined techniques to deposit CdTe based solar cells by a spray pyrolys... more The program reported has examined techniques to deposit CdTe based solar cells by a spray pyrolysis process called Reductive Multichemical Deposition (RMD). The principles of the process and the major results obtained during the program are appended. Results of electrical testing performed on films and devices are presented, and the experiments performed on the CdS layer are discussed. Improving the quality of the CdS layer, the CdS surface CdS/CdTe interface was deemed to be crucial in increasing device performance. In addition, films of CuIn Seâ were spray deposited in order to investigate further the potential power of the RMD process. (LEW)

Thin films of CdTe were vacuum deposited onto glass and ITO-coated glass substrates using a hot-w... more Thin films of CdTe were vacuum deposited onto glass and ITO-coated glass substrates using a hot-wall technique. Improved source conditions and system cleanliness enabled large pinhole-free regions capable of providing large area evaporated Au devices (greater than 1 cm(2)). An optimized Au thickness was determined and characterized in terms of sheet resistance and optical transmission. An evaporated Au/Ag combined grid and a SiO Ar coating yielded 1 sq cm active area Au-CdTe-ITO devices with J/sub sc/ = 13 mA/sq cm and /sub oc/ of 0.43 volt. The 1.4% efficiency is only temporarily limited by the uncharacteristically low 0.25 fill factor which is believed to be caused by an anomaly near the ITO contact. A three-source system with effusion cell type sources and a rotary shutter was designed, built, and successfully tested; it should improve control over film and device reproducibility and also provide greater versatility in controlling doping concentration and film stoichiometry. The ...

Research was conducted with the goal of demonstrating the feasibility of designing a novel nondes... more Research was conducted with the goal of demonstrating the feasibility of designing a novel nondestructive, radiometric instrument to accurately quantify the levels of iron, titanium, and other metals in circulating lubricating media at the tens of parts-per-million (ppm) concentration level. The laboratory apparatus for conducting the research was straightforward and consisted of a vertical cylindrical tube with x-ray transparent ends, a radioactive source at one end of the tube, a detector and associated electronics at the other end, and a multichannel analyzer. The tube was repetitively filled to various levels by lubricating media containing various minute amounts of iron on titanium. The data were acquired and analyzed for the direct purpose of determining the ultimate sensitivity. Researchers found that the instrument could detect 10 ppm of iron and 15 ppm of titanium concentration levels in the lubricating medium once the experimental setup was optimized.

This paper reviews superconducting magnets and high T(sub c) superconducting oxide ceramic materi... more This paper reviews superconducting magnets and high T(sub c) superconducting oxide ceramic materials technology to identify areas of fundamental impasse to the fabrication of components and devices that tap what are believed to be the true potential of these new materials. High T(sub c) ceramics pose problems in fundamentally different areas which need to be solved unlike low T(sub c) materials. The authors map out an experimental plan designed to research process technologies which, if suitably implemented, should allow these deficiencies to be solved. Finally, assessments are made of where and on what regimes magnetic system designers should focus their attention to advance the practical development of systems based on these new materials.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1994

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1990

... Nuclear Instruments and Methods in Physics Research A288 (1990) 137-139 137 North-Holland LAR... more ... Nuclear Instruments and Methods in Physics Research A288 (1990) 137-139 137 North-Holland LARGE AREA SILICON AVALANCHE PHOTODIODES FOR SCINTILLATION DETECTORS R. FARRELL, F. OLSCHNER, E. FREDERICK, L. McCONCHIE ... [2] K. Beard, University of ...

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1990

ABSTRACT

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1992

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1994

2021 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)

This research investigated a new spray pyrolysis technique for depositing cost effective, thin fi... more This research investigated a new spray pyrolysis technique for depositing cost effective, thin films of CuInSe/sub 2/ for terrestrial solar cell applications. This process is attractive because of its inherent simplicity which has permitted large scale production of high quality, thin films at low cost of a variety of materials. This program was directed at determining the chemical and physical conditions required to produce high quality films and at characterizing and understanding the properties of the films produced. During this research effort, we investigated the spray solution chemistry, the deposition parameters, the film properties, and the characteristics of solar cell devices fabricated using the sprayed films. The results are very encouraging but further work is needed to fully examine the use of this unique deposition process in the manufacturing of CuInSe/sub 2/ solar cells.

Research was conducted with the goal of demonstrating the feasibility of designing a novel nondes... more Research was conducted with the goal of demonstrating the feasibility of designing a novel nondestructive, radiometric instrument to accurately quantify the levels of iron, titanium, and other metals in circulating lubricating media at the tens of parts-per-million (ppm) concentration level. The laboratory apparatus for conducting the research was straightforward and consisted of a vertical cylindrical tube with x-ray transparent ends, a radioactive source at one end of the tube, a detector and associated electronics at the other end, and a multichannel analyzer. The tube was repetitively filled to various levels by lubricating media containing various minute amounts of iron on titanium. The data were acquired and analyzed for the direct purpose of determining the ultimate sensitivity. Researchers found that the instrument could detect 10 ppm of iron and 15 ppm of titanium concentration levels in the lubricating medium once the experimental setup was optimized.

MRS Proceedings, 1982

ABSTRACTRecent developments on HgI2 detectors fabricated from platelets grown by the Polymer Cont... more ABSTRACTRecent developments on HgI2 detectors fabricated from platelets grown by the Polymer Controller Growth (PCG) technique have resulted in a better understanding of this remarkable process and provide increased hope for the future of room temperature operable, high resolution x-ray detectors. The benefits of PCG are higher purity using reagent grade materials, better control of stoichiometry, rapid growth, and simplified fabrication. This latter benefit is even more significant when the extreme fragility of HgI2 crystals is considered. The problems of device resolution crystal stability and uniformity, and control ot platelet growth were investigated under a NASA funded program. HgI2 devices fabricated from PCG platelets gave room temperature energy resolutions under 400 eV (FWHM) for the 5.9 eV Mn x-ray. Models for the polymer assisted transport are discussed along with an analysis of spectra obtained from PCG grown devices. Reproducibility has been demonstrated both for plate...

2006 IEEE Nuclear Science Symposium Conference Record, 2006

MRS Proceedings, 1997

Single crystals of InI (Eg = 2.01 eV at 300K) have been grown by vertical Bridgman technique usin... more Single crystals of InI (Eg = 2.01 eV at 300K) have been grown by vertical Bridgman technique using zone refined (ZR) starting materials. The quality of the grown crystal has been evaluated by X-ray diffraction (XRD), Electron probe microanalysis (EPMA) and Photoelectron spectroscopy (XPS). Chemically etched crystal wafer has been used to fabricate optical and nuclear detectors. The results are presented in this paper.

MRS Proceedings, 1982

ABSTRACTSilicon avalanche photodiodes have recently been shown to be a potential replacement for ... more ABSTRACTSilicon avalanche photodiodes have recently been shown to be a potential replacement for vacuum tube photomultipliers in many nuclear scintillation detector applications. The large active area, low noise, and ease of use of these solid-state photomultipliers makes them ideally suited to scintillation detector applications where overall size and ruggedness are a major concern. Historically, avalanche photodiodes have been limited for use in this capacity by small active areas, low internal gains, and poor optical sensitivity at the wavelengths at which most solid scintillator materials emit. Recent advances as the result of research aimed directly at the solution to these problems however, have successfully demonstrated one inch active area silicon avalanche photodiodes which produce a FWHM resolution of 9.5% for Cs137 at room temperature when coupled to a 1″ × 1″ NaI(Tl) scintillation crystal. Improvements to both material quality and device structure have advanced the state...

Radiology, 1991

An automatic exposure controller has been designed that controls the optical film density for fil... more An automatic exposure controller has been designed that controls the optical film density for film, screen, and radiographic techniques typically used in mammography to within 0.05 over a range of 1.3-6.7-cm thickness of Lucite. This degree of accuracy is better than that reported for presently available controllers. The detector system consists of four cadmium telluride detectors and involves the use of a control algorithm to read the detectors and turn off the mammography unit at the correct time. This algorithm is implemented by a microprocessor, which also provides the means for a convenient calibration.

MRS Proceedings, 1999

ABSTRACTThe fabrication and testing of screen printed dye-sensitized large solar cell (15 cm × 15... more ABSTRACTThe fabrication and testing of screen printed dye-sensitized large solar cell (15 cm × 15 cm) based on nanocrystalline TiO2 is described. It is the largest photo-electrochemical (PEC) cell that is based on the dye sensitization of thin (8-18 μm) films of TiO2 nanoparticles in contact with a non-aqueous liquid electrolyte. The cell has the potential to be a low cost, commercial, environmentally friendly, photovoltaic option. Surface as well as electrical characterization, of the nanostructured PEC cells have been performed. The efficiency of these large commercial cells are compared to the laboratory-made small PEC cells. Key words: Photoelectrochemical, solar cells, nanocrystalline, dye-sensitized

Radiation Detectors: Systems and Applications XV, 2014

ABSTRACT Numerous instruments have been developed for performing gamma-ray imaging and neutron im... more ABSTRACT Numerous instruments have been developed for performing gamma-ray imaging and neutron imaging for research, nondestructive testing, medicine and national security. However, none are capable of imaging gamma-rays and neutrons simultaneously while also discriminating gamma-rays from the neutron. This paper will describe recent experimental results obtained using a gamma/neutron camera based on Cs2LiYCl6:Ce (CLYC) scintillation crystals, which can discriminate gamma-rays from neutrons. The ability to do this while also having good energy resolution provides a powerful capability for detecting and identifying shielded special nuclear materials for security applications. Also discussed are results obtained using a LaBr3 scintillation crystal.

IEEE Nuclear Science Symposium Conference Record, 2012

ABSTRACT RadCam™ is a detection system developed by RMD for gamma ray imaging. The system images ... more ABSTRACT RadCam™ is a detection system developed by RMD for gamma ray imaging. The system images and tracks radiation contamination and its distribution. The current system is based on a CsI:Na scintillator coupled to a position-sensitive photomultiplier tube (PS-PMT). The image is obtained either using MURA coded aperture or pin-hole masks. Detected signals are decoded to produce radiation distribution that is overlaid on an image from a video camera (real-time). Due to increased focus on neutron detection, we recently started upgrading the system with a new scintillating material capable of simultaneous gamma ray and neutron detection - Cs2LiYCl6 (CLYC). Due to excellent pulse-shape discrimination, CLYC provides dual-mode detection of gamma-rays and neutrons while cleanly separating the signals from these two types of radiation. In addition, CLYC delivers better energy resolution than classical scintillators, such as CsI:Na. In this paper we present our initial results obtained with a system in which the original CsI:Na crystal was replaced with a CLYC scintillator.

The program reported has examined techniques to deposit CdTe based solar cells by a spray pyrolys... more The program reported has examined techniques to deposit CdTe based solar cells by a spray pyrolysis process called Reductive Multichemical Deposition (RMD). The principles of the process and the major results obtained during the program are appended. Results of electrical testing performed on films and devices are presented, and the experiments performed on the CdS layer are discussed. Improving the quality of the CdS layer, the CdS surface CdS/CdTe interface was deemed to be crucial in increasing device performance. In addition, films of CuIn Seâ were spray deposited in order to investigate further the potential power of the RMD process. (LEW)

Thin films of CdTe were vacuum deposited onto glass and ITO-coated glass substrates using a hot-w... more Thin films of CdTe were vacuum deposited onto glass and ITO-coated glass substrates using a hot-wall technique. Improved source conditions and system cleanliness enabled large pinhole-free regions capable of providing large area evaporated Au devices (greater than 1 cm(2)). An optimized Au thickness was determined and characterized in terms of sheet resistance and optical transmission. An evaporated Au/Ag combined grid and a SiO Ar coating yielded 1 sq cm active area Au-CdTe-ITO devices with J/sub sc/ = 13 mA/sq cm and /sub oc/ of 0.43 volt. The 1.4% efficiency is only temporarily limited by the uncharacteristically low 0.25 fill factor which is believed to be caused by an anomaly near the ITO contact. A three-source system with effusion cell type sources and a rotary shutter was designed, built, and successfully tested; it should improve control over film and device reproducibility and also provide greater versatility in controlling doping concentration and film stoichiometry. The ...

Research was conducted with the goal of demonstrating the feasibility of designing a novel nondes... more Research was conducted with the goal of demonstrating the feasibility of designing a novel nondestructive, radiometric instrument to accurately quantify the levels of iron, titanium, and other metals in circulating lubricating media at the tens of parts-per-million (ppm) concentration level. The laboratory apparatus for conducting the research was straightforward and consisted of a vertical cylindrical tube with x-ray transparent ends, a radioactive source at one end of the tube, a detector and associated electronics at the other end, and a multichannel analyzer. The tube was repetitively filled to various levels by lubricating media containing various minute amounts of iron on titanium. The data were acquired and analyzed for the direct purpose of determining the ultimate sensitivity. Researchers found that the instrument could detect 10 ppm of iron and 15 ppm of titanium concentration levels in the lubricating medium once the experimental setup was optimized.

This paper reviews superconducting magnets and high T(sub c) superconducting oxide ceramic materi... more This paper reviews superconducting magnets and high T(sub c) superconducting oxide ceramic materials technology to identify areas of fundamental impasse to the fabrication of components and devices that tap what are believed to be the true potential of these new materials. High T(sub c) ceramics pose problems in fundamentally different areas which need to be solved unlike low T(sub c) materials. The authors map out an experimental plan designed to research process technologies which, if suitably implemented, should allow these deficiencies to be solved. Finally, assessments are made of where and on what regimes magnetic system designers should focus their attention to advance the practical development of systems based on these new materials.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1994

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1990

... Nuclear Instruments and Methods in Physics Research A288 (1990) 137-139 137 North-Holland LAR... more ... Nuclear Instruments and Methods in Physics Research A288 (1990) 137-139 137 North-Holland LARGE AREA SILICON AVALANCHE PHOTODIODES FOR SCINTILLATION DETECTORS R. FARRELL, F. OLSCHNER, E. FREDERICK, L. McCONCHIE ... [2] K. Beard, University of ...

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1990

ABSTRACT

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1992

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1994