The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Robert Elliman - One of the best experts on this subject based on the ideXlab platform.
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Origins of the residual pulse height deficit in propane-filled Gas Ionization detectors
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2005Co-Authors: T.d.m. Weijers-dall, Heiko Timmers, Robert EllimanAbstract:Abstract This work investigates the origins of the residual pulse height deficit in Gas Ionization detectors. It is motivated by the recent observation that the species dependence of Gas detector response cannot be accounted for solely by considering the energy loss of the ions in the detector window and non-ionizing energy loss processes in the detector Gas. It was found that the residual pulse height deficit is approximately proportional to the square of the Ionization density. However, only a weak dependence of the residual deficit on Gas pressure (in the range 70– 120 mbar ) was observed. It is hypothesized that the residual pulse height deficit in Gas Ionization detectors results from the effect of multiple Ionization of individual Gas molecules at high Ionization densities on the energy required to create an electron–ion pair.
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Hydrogen detection with a Gas Ionization elastic recoil detector
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2004Co-Authors: Robert Elliman, Heiko Timmers, T.d.m. WeijersAbstract:Abstract The capabilities of a large solid angle Gas Ionization detector have been evaluated for the detection of elastic recoil protons. The use of various electrode signals is examined for the determination of total hydrogen concentrations and depth profiles. Moderate resolution depth profiles, comparable to those obtained with the standard recoil techniques using low energy, α-particle beams, are possible with a reduced but reasonable detector acceptance (∼1 msr). It has been confirmed that multiple scattering effects become the dominant factor in determining the depth resolution achievable for surface films containing elements beyond about Z=20.
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Unique capabilities of heavy ion elastic recoil detection with Gas Ionization detectors
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2002Co-Authors: Heiko Timmers, T.d.m. Weijers, Robert EllimanAbstract:Abstract Specific aspects of heavy ion elastic recoil detection (ERD) with Gas Ionization detectors have been studied using representative measurements. A particular strength of the technique is the detection and direct quantification of elements with atomic numbers in the range Z=2–8, which are often not accessible with other ion beam techniques. Within the wider spectrum of analytical techniques in materials science, heavy ion ERD has unique capabilities, when the particular problem requires in addition the analysis of heavy elements or hydrogen detection. Whenever only heavy element analysis or only hydrogen profiling is of interest, alternative techniques tend to be superior.
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A systematic study of the pulse height deficit in propane-filled Gas Ionization detectors
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2002Co-Authors: T.d.m. Weijers, Heiko Timmers, T.r. Ophel, Robert EllimanAbstract:Abstract The response of Gas Ionization detectors to heavy ions is species dependent. Relative to a linear calibration based on the response to light ions, heavy ions show a pulse height deficit. Detailed knowledge of this deficit is essential for accurate energy spectroscopy of heavy ions. Precise measurements of the response of a propane-filled Gas Ionization detector have been performed for a large selection of ions in the ranges Z =6–79 and E =0.4–2.6 MeV/amu. Pulse height deficits were determined with respect to the response to carbon ions, and found to be as large as 25% of the incident energy. The deficit was found to depend on ion energy and atomic number. Isotopic effects were also observed. Care was taken to obtain a reliable estimate of the energy loss of the ions in the detector window. This included measurements of the window thickness and shape, and measurements of heavy ion stopping powers for Mylar. Monte-Carlo simulations were carried out using the code TRIM to evaluate the contribution of elastic collisions of the ions in the detector Gas. It was found that after accounting for both window energy loss and elastic collisions, a significant residual pulse height deficit remains. An empirical formula was developed to predict the magnitude of the pulse height deficit, and aid in the accurate energy calibration of Gas Ionization detectors.
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Heavy ion ERD of nitrides with a position-sensitive Gas Ionization detector
AIP Conference Proceedings, 2001Co-Authors: Heiko Timmers, Robert Elliman, T.d.m. Weijers, T.r. OphelAbstract:A Gas Ionization detector with novel design features has been developed for the compositional depth-profiling of materials with Elastic Recoil Detection (ERD) using very heavy incident beams. The detector features a large solid angle and thus has high detection efficiency. The detection of the ion position using a saw-tooth ΔE electrode within the anode is energy and species independent and enables the correction of kinematic energy broadening. The energy information is obtained from a single grid-electrode, which considerably simplifies data analysis. All chemical elements, including hydrogen, can be detected simultaneously with similar sensitivity. While it is versatile and applicable to many materials, the technique has unique capabilities when applied to thin films containing carbon, nitrogen or oxygen in combination with heavier elements and hydrogen. In contrast to other techniques, heavy ion ERD resolves all elements in a single measurement and the experimental uncertainty is limited only by counti...
Mojtaba Kahrizi - One of the best experts on this subject based on the ideXlab platform.
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Advances in Gas Ionization sensors based on nanostructured materials: a review
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Parsoua A. Sohi, Mojtaba KahriziAbstract:In this review article collection of summary of research works related to Gas Ionization sensors based on nanostructured materials is attempted. Among physical Gas sensors, Gas Ionization sensor is used to identify Gases based on breakdown of ionized Gases as each Gas has a unique breakdown voltage. The sensor is generally, made of two parallel electrodes separated by a narrow gap. Nanostructures, usually metallic or semiconducting, in from of nanowires/nanorods are places between the two plates. These structures act as electric field amplifiers to enhance the electric field intensity to reduce the breakdown voltages of the Gases. Numerous investigations revealed that type of materials and their physical properties play important roles in the sensor characteristics and their operations. Identifying materials to optimize the strength of electric field and generate large field enhancement is a crucial step towards this application. Carbon nanotubes were among the first candidates to utilize in these structures and in fact, they were used to prove the principle of the device. The very first developed sensor showed that using carbon nanotubes between the two parallel plates of the sensor reduces the required applied voltages to ionize Gases up to one order of magnitude. Since 2003 many studies are done to improve the performance and physical properties like sensitivity, selectivity, durability and stability of the device by incorporating various materials in form of nanowires/nanorods inside the device structure. In this work, first the fundamental structure of Gas Ionization sensor and the theory of their operations like field emission, field Ionization and quantum tunneling phenomena are presented. Then, related research works reported in the literature are summarized. This review article is partitioned based on the materials used in the structure of the device as they play the most effective role in their performances. It is started with studies on devices based on carbon nanotubes, and then those used metallic nanowires followed by works done using semiconductor nanostructure to develop the device. The review started from the oldest articles in each category carried on to the most recent published works. All essential parameters effecting the structures and operations of the reported devices including their pros and cons are discussed.
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Modeling and Simulation of a Miniaturized Gas Ionization Sensor: Detection of Greenhouse Gases
2013Co-Authors: Nicoleta Chivu, Mojtaba KahriziAbstract:Gas Ionization sensor (GIS), made of two parallel plates, works on measuring the breakdown voltage of Gases that is unique for each Gas. The Gas breakdown inside the Gas chamber occurs due to the Ionization of Gas molecules by accelerated electron impacts. The acceleration of electrons is very depended on the effective electric field they experience. It is shown that metallic or semiconductor nanowires grown between the two plates improve the sensitivity of the device and breakdown voltages of the Gases are considerably reduced. In this work we report the design, modeling, and simulation of a miniaturized GIS based on nanowires. We have developed simulating software based on an open source simulator XOOPIC. The simulation tool is based on combined Particle-In-Cell and Monte-Carlo-Collision approaches. The tool is developed to model and simulate the Gas Ionization sensor to detect various Gases including greenhouse Gases with optimized breakdown voltages. Copyright © 2013 IFSA.
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Design, modeling and simulation of a miniaturized Gas Ionization sensor: Optimization of the structure and operation
2012 IEEE International Conference on Industrial Technology, 2012Co-Authors: Nicoleta Chivu, Mojtaba KahriziAbstract:Gas Ionization sensor (GIS) work on measuring the breakdown voltage of Gases that is unique for each Gas. The Gas breakdown inside the Gas chamber occurs due to the Ionization of Gas molecules by accelerated electron impacts. The acceleration of electrons is very depending on the effective electric field applied on them. In this work we report the design, modeling, and simulation of a miniaturized GIS based on nanowires. In this report it is shown that the local electric field (responsible for the breakdown of Gases) at the nanowire tip can be enhanced by optimizing the device structure and parameters such as nanowires shapes, the distance between the nanowires, and the nanowires lengths. We have developed simulating software based on an open source simulator XOOPIC. The simulation tool is based on combined Particle-In-Cell and Monte-Carlo-Collision approaches. The tool is developed to model and simulate the Gas Ionization sensor to detect various Gases with optimized breakdown volatges. In order to enhance and speed up the design and simulations, the effective electric field, and screening effect due to the interaction between electric fields of individual nanowires were preliminary studies. For this we used COMSOL, a multiphysics simulation tool, and the results of these studies were used to model the device utilizing XOOPIC. In our model we have achieved designs for the devices with faster response and lower breakdown voltages for various Gases.
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IECON - ZnO crystalline nanowires array for application in Gas Ionization sensor
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012Co-Authors: Svetlana Spitsina, Mojtaba KahriziAbstract:The air monitoring becomes daily necessity not only in industrial environment and in aerospace applications but also in a living milieu as a consequence of the Gas pollution. For detection of Gaseous pollutants Gas sensors are employed. In this work the successful p-type and n-type ZnO nanowires (NWs) were accomplished during electrochemical deposition. P-type ZnO NWs doped with Ag dopant were achieved with omitted post annealing procedure. Also, the novel Gas Ionization sensor (GIS) with integrated p-type ZnO NWs as the anode is proposed. P-type ZnO NWs-based Gas sensor's characteristics compared with the gold NWs-based GIS, which was developed and reported by our group previously. It showed the comparable breakdown voltages in inert Gas (Ar) atmosphere. P-type ZnO NWs-based GIS demonstrated good repeatability. The practical and low cost p-type ZnO NWs-based Gas sensor presented in this article shows potential for future implementation in real world Gas sensors' applications.
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A silver nanowire based Gas Ionization sensor EUROCON2009
IEEE EUROCON 2009, 2009Co-Authors: Nika Azmoodeh, Nicoleta Chivu, Ramin Banan Sadeghian, Mojtaba KahriziAbstract:We report fabrication and successful testing of a Gas Ionization sensor made of silver nanowires (AgNWs) sandwiched between two parallel plates. The device was tested in low pressure argon Gas (0.1≤ P ≤10−4 torr) where the breakdown voltages (V b ) were recorded against pressure. The new device displayed considerably lower V b compared to its gold nanowire (AuNW)-based counterparts. The reduction of Vb was justified based on the increase in the secondary electron emission factor on AgNWs due to the lower workfunction of silver. We have also developed a simulation tool to model the device. Our model is based on combined Particle-In-Cell and Monte-Carlo-Collision (PIC-MCC) approaches which provides a platform for further development and optimization of the device.
Heiko Timmers - One of the best experts on this subject based on the ideXlab platform.
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Origins of the residual pulse height deficit in propane-filled Gas Ionization detectors
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2005Co-Authors: T.d.m. Weijers-dall, Heiko Timmers, Robert EllimanAbstract:Abstract This work investigates the origins of the residual pulse height deficit in Gas Ionization detectors. It is motivated by the recent observation that the species dependence of Gas detector response cannot be accounted for solely by considering the energy loss of the ions in the detector window and non-ionizing energy loss processes in the detector Gas. It was found that the residual pulse height deficit is approximately proportional to the square of the Ionization density. However, only a weak dependence of the residual deficit on Gas pressure (in the range 70– 120 mbar ) was observed. It is hypothesized that the residual pulse height deficit in Gas Ionization detectors results from the effect of multiple Ionization of individual Gas molecules at high Ionization densities on the energy required to create an electron–ion pair.
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Hydrogen detection with a Gas Ionization elastic recoil detector
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2004Co-Authors: Robert Elliman, Heiko Timmers, T.d.m. WeijersAbstract:Abstract The capabilities of a large solid angle Gas Ionization detector have been evaluated for the detection of elastic recoil protons. The use of various electrode signals is examined for the determination of total hydrogen concentrations and depth profiles. Moderate resolution depth profiles, comparable to those obtained with the standard recoil techniques using low energy, α-particle beams, are possible with a reduced but reasonable detector acceptance (∼1 msr). It has been confirmed that multiple scattering effects become the dominant factor in determining the depth resolution achievable for surface films containing elements beyond about Z=20.
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Unique capabilities of heavy ion elastic recoil detection with Gas Ionization detectors
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2002Co-Authors: Heiko Timmers, T.d.m. Weijers, Robert EllimanAbstract:Abstract Specific aspects of heavy ion elastic recoil detection (ERD) with Gas Ionization detectors have been studied using representative measurements. A particular strength of the technique is the detection and direct quantification of elements with atomic numbers in the range Z=2–8, which are often not accessible with other ion beam techniques. Within the wider spectrum of analytical techniques in materials science, heavy ion ERD has unique capabilities, when the particular problem requires in addition the analysis of heavy elements or hydrogen detection. Whenever only heavy element analysis or only hydrogen profiling is of interest, alternative techniques tend to be superior.
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A systematic study of the pulse height deficit in propane-filled Gas Ionization detectors
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2002Co-Authors: T.d.m. Weijers, Heiko Timmers, T.r. Ophel, Robert EllimanAbstract:Abstract The response of Gas Ionization detectors to heavy ions is species dependent. Relative to a linear calibration based on the response to light ions, heavy ions show a pulse height deficit. Detailed knowledge of this deficit is essential for accurate energy spectroscopy of heavy ions. Precise measurements of the response of a propane-filled Gas Ionization detector have been performed for a large selection of ions in the ranges Z =6–79 and E =0.4–2.6 MeV/amu. Pulse height deficits were determined with respect to the response to carbon ions, and found to be as large as 25% of the incident energy. The deficit was found to depend on ion energy and atomic number. Isotopic effects were also observed. Care was taken to obtain a reliable estimate of the energy loss of the ions in the detector window. This included measurements of the window thickness and shape, and measurements of heavy ion stopping powers for Mylar. Monte-Carlo simulations were carried out using the code TRIM to evaluate the contribution of elastic collisions of the ions in the detector Gas. It was found that after accounting for both window energy loss and elastic collisions, a significant residual pulse height deficit remains. An empirical formula was developed to predict the magnitude of the pulse height deficit, and aid in the accurate energy calibration of Gas Ionization detectors.
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Heavy ion ERD of nitrides with a position-sensitive Gas Ionization detector
AIP Conference Proceedings, 2001Co-Authors: Heiko Timmers, Robert Elliman, T.d.m. Weijers, T.r. OphelAbstract:A Gas Ionization detector with novel design features has been developed for the compositional depth-profiling of materials with Elastic Recoil Detection (ERD) using very heavy incident beams. The detector features a large solid angle and thus has high detection efficiency. The detection of the ion position using a saw-tooth ΔE electrode within the anode is energy and species independent and enables the correction of kinematic energy broadening. The energy information is obtained from a single grid-electrode, which considerably simplifies data analysis. All chemical elements, including hydrogen, can be detected simultaneously with similar sensitivity. While it is versatile and applicable to many materials, the technique has unique capabilities when applied to thin films containing carbon, nitrogen or oxygen in combination with heavier elements and hydrogen. In contrast to other techniques, heavy ion ERD resolves all elements in a single measurement and the experimental uncertainty is limited only by counti...
Jinhuai Liu - One of the best experts on this subject based on the ideXlab platform.
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A novel highly sensitive Gas Ionization sensor for ammonia detection
Sensors and Actuators A: Physical, 2009Co-Authors: Jiarui Huang, Junhai Wang, Fanli Meng, Jinhuai LiuAbstract:A novel highly sensitive Gas Ionization sensor for ammonia detection in ambient air is introduced in this paper. Carbon nanotubes (CNTs) grown on silicon substrate were incorporated to fabricate a Gas Ionization sensor. Application of a positive bias to the CNTs generates electric fields sufficiently to field-ionize passing Gas-phase molecular and initiate a prebreakdown current. When the CNTs film is configured as the cathode, secondary electrons repelled away from the CNTs tips into the gap spacing make more ionizing collisions and also initiate a prebreakdown current. By monitoring the prebreakdown current, the Gas Ionization sensor was demonstrated to be capable of ionizing and detecting the ammonia and with a linear response over the entire range from 1 to 160 ppm ammonia in air. The sensitivity mechanism of the Gas Ionization sensor was also discussed in detail. The sensitivity and selectivity of the Gas Ionization sensor to the Gases is not only dependent on its Ionization energy but also its electric dipole moment. The novel CNTs-based Gas Ionization sensor described here exhibits high accuracy, repeatability and stability. The sensor is promising for use in various fields.
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Dynamic Prebreakdown Current Measurement of Nanotips-Based Gas Ionization Sensor Application at Ambient Atmosphere
IEEE Sensors Journal, 2009Co-Authors: Fanli Meng, Jiarui Huang, Yan Chen, Yong Jia, Jinyun Liu, Jinhuai LiuAbstract:A Gas Ionization sensor (GIS) with nanotips as anode and tungsten needle as cathode was fabricated, which is working with moderate input voltage. Controlled dc voltage was applied, and the prebreakdown currents were measured. The sensor can be used to determine target Gases at ambient atmosphere. A novel dynamic prebreakdown current measurement was exploited which can decrease the noise interference and improve the stability of the GIS. It is discussed in detail about the advantages of the dynamic prebreakdown current measurement and its influence factors. In addition, carbon nanotubes and zinc oxide nanorods were used as Ionization tips, respectively. Their anti-oxidation performances were indicated by experiment.
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Fabrication of Gas Ionization sensors using well-aligned MWCNT arrays grown in porous AAO templates
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2007Co-Authors: Xing Chen, Fanli Meng, Zhenhua Guo, Jarui Huang, Mei-yun Zhang, Jinhuai LiuAbstract:Gas Ionization sensors based on the field Ionization from well-aligned MWCNT arrays grown in porous AAO templates were fabricated. The breakdown voltages were measured in different Gases of different concentrations. The changes of the breakdown voltage were related to the type of detected Gases and its concentration. At the same time, the pre-discharge processes had also been studied to test the responses of the Gases sensors to several Gases. It was found that the as-prepared Gas Ionization sensors using well-aligned MWCNT arrays grown in porous AAO templates have shown good sensitivity to acetic acid with short response or recovery time.
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Gas Ionization sensors using well-aligned MWCNT arrays grown in porous AAO template
2005 IEEE International Conference on Information Acquisition, 1Co-Authors: Xing Chen, Jiarui Huang, Jinhuai Liu, Zhongying Huang, Mingguang KongAbstract:Porous anodic aluminum oxide (AAO) templates were prepared by a two-step anodization process, then chemical vapor deposition (CVD) method was used to prepare well-aligned open-ended multiwall carbon nanotube (MWCNT) arrays in the AAO templates that also served as catalyst. Gas Ionization sensors were fabricated using the MWCNT arrays. The Gas Ionization sensors featured the electrical breakdown of the ethanol vapor of different concentrations at the carbon nanotube tips, the breakdown voltage decreased with the increase of the ethanol quantity. They had showed good sensitivity and repeatability for detecting ethanol vapor of low concentration in the test Gas.
T.d.m. Weijers - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen detection with a Gas Ionization elastic recoil detector
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2004Co-Authors: Robert Elliman, Heiko Timmers, T.d.m. WeijersAbstract:Abstract The capabilities of a large solid angle Gas Ionization detector have been evaluated for the detection of elastic recoil protons. The use of various electrode signals is examined for the determination of total hydrogen concentrations and depth profiles. Moderate resolution depth profiles, comparable to those obtained with the standard recoil techniques using low energy, α-particle beams, are possible with a reduced but reasonable detector acceptance (∼1 msr). It has been confirmed that multiple scattering effects become the dominant factor in determining the depth resolution achievable for surface films containing elements beyond about Z=20.
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Unique capabilities of heavy ion elastic recoil detection with Gas Ionization detectors
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2002Co-Authors: Heiko Timmers, T.d.m. Weijers, Robert EllimanAbstract:Abstract Specific aspects of heavy ion elastic recoil detection (ERD) with Gas Ionization detectors have been studied using representative measurements. A particular strength of the technique is the detection and direct quantification of elements with atomic numbers in the range Z=2–8, which are often not accessible with other ion beam techniques. Within the wider spectrum of analytical techniques in materials science, heavy ion ERD has unique capabilities, when the particular problem requires in addition the analysis of heavy elements or hydrogen detection. Whenever only heavy element analysis or only hydrogen profiling is of interest, alternative techniques tend to be superior.
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A systematic study of the pulse height deficit in propane-filled Gas Ionization detectors
Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2002Co-Authors: T.d.m. Weijers, Heiko Timmers, T.r. Ophel, Robert EllimanAbstract:Abstract The response of Gas Ionization detectors to heavy ions is species dependent. Relative to a linear calibration based on the response to light ions, heavy ions show a pulse height deficit. Detailed knowledge of this deficit is essential for accurate energy spectroscopy of heavy ions. Precise measurements of the response of a propane-filled Gas Ionization detector have been performed for a large selection of ions in the ranges Z =6–79 and E =0.4–2.6 MeV/amu. Pulse height deficits were determined with respect to the response to carbon ions, and found to be as large as 25% of the incident energy. The deficit was found to depend on ion energy and atomic number. Isotopic effects were also observed. Care was taken to obtain a reliable estimate of the energy loss of the ions in the detector window. This included measurements of the window thickness and shape, and measurements of heavy ion stopping powers for Mylar. Monte-Carlo simulations were carried out using the code TRIM to evaluate the contribution of elastic collisions of the ions in the detector Gas. It was found that after accounting for both window energy loss and elastic collisions, a significant residual pulse height deficit remains. An empirical formula was developed to predict the magnitude of the pulse height deficit, and aid in the accurate energy calibration of Gas Ionization detectors.
-
Heavy ion ERD of nitrides with a position-sensitive Gas Ionization detector
AIP Conference Proceedings, 2001Co-Authors: Heiko Timmers, Robert Elliman, T.d.m. Weijers, T.r. OphelAbstract:A Gas Ionization detector with novel design features has been developed for the compositional depth-profiling of materials with Elastic Recoil Detection (ERD) using very heavy incident beams. The detector features a large solid angle and thus has high detection efficiency. The detection of the ion position using a saw-tooth ΔE electrode within the anode is energy and species independent and enables the correction of kinematic energy broadening. The energy information is obtained from a single grid-electrode, which considerably simplifies data analysis. All chemical elements, including hydrogen, can be detected simultaneously with similar sensitivity. While it is versatile and applicable to many materials, the technique has unique capabilities when applied to thin films containing carbon, nitrogen or oxygen in combination with heavier elements and hydrogen. In contrast to other techniques, heavy ion ERD resolves all elements in a single measurement and the experimental uncertainty is limited only by counti...
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Simultaneous hydrogen detection with an ERD Gas Ionization detector
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2000Co-Authors: Robert Elliman, Heiko Timmers, T.d.m. Weijers, T.r. Ophel, L.s. Wielunski, Geoffrey L. HardingAbstract:Abstract A large solid-angle Gas Ionization detector is shown to be capable of simultaneous hydrogen detection during heavy-ion elastic recoil detection of heavier elements. Different modes of detection are possible depending on the specific application. These include a transmission-mode in which the primary ion energy and Gas-pressure in the detector are optimized for heavy-ion detection and energy loss signals are recorded for each hydrogen recoil. Alternatively, the primary ion energy can be reduced and the Gas pressure in the detector increased so that the recoiled protons are fully stopped in the detector. In this case, a conventional total energy signal can be recorded. The transmission mode is shown to be particularly suited to determining the total hydrogen content of thin films, where the emphasis is on optimum mass and depth resolution for the heavy elements, whilst the stopped mode allows simultaneous hydrogen profiling with reasonable depth resolution.
