scholarly journals Advances in Spectral Distribution Assessment of Laser Accelerated Protons using Multilayer CR-39 Detectors

2019 ◽  
Vol 9 (10) ◽  
pp. 2052 ◽  
Author(s):  
Andreea Groza ◽  
Mihai Serbanescu ◽  
Bogdan Butoi ◽  
Elena Stancu ◽  
Mihai Straticiuc ◽  
...  
Keyword(s):  
Calibration Curve ◽  
Spectral Distribution ◽  
Incident Energy ◽  
Front Side ◽  
Force Microscopy ◽  
Proton Track ◽  
Accelerated Protons ◽  
Cr 39 Detectors ◽  
Track Diameter ◽  
Proton Incident

We show that a spectral distribution of laser-accelerated protons can be extracted by analyzing the proton track diameters observed on the front side of a second CR-39 detector arranged in a stack. The correspondence between the proton track diameter and the incident energy on the second detector is established by knowing that protons with energies only higher than 10.5 MeV can fully deposit their energy in the second CR-39 detector. The correlation between the laser-accelerated proton track diameters observed on the front side of the second CR-39 detector and the proton incident energy on the detector stack is also presented. By calculating the proton number stopped in the CR-39 stack, we find out that its dependence on the proton energy in the 1–15 MeV range presents some discontinuities at energies higher than 9 MeV. Thus, we build a calibration curve of the track diameter as a function of the proton incident energy within the 1–9 MeV range, and we infer the associated analytical function as the calculations performed indicate best results for proton spectra within the 1–9 MeV range. The calibration curve is used as a tool to ascertain the pits identified on the surfaces of both CR-39 detectors to proton tracks. The proton tracks spatial distribution analyzed by optical and atomic force microscopy is correlated with the peculiarity of the used targets.

Experimental evaluation of protons emission from a plasma focus device

2012 ◽  
Vol 78 (5) ◽  
pp. 507-513 ◽  
Author(s):  
M. BHUYAN ◽  
S. R. MOHANTY
Keyword(s):  
Plasma Focus ◽  
Proton Energy ◽  
Plasma Focus Device ◽  
Etching Time ◽  
Number Density ◽  
Pinched Plasma ◽  
Filter Thickness ◽  
Aluminum Filter ◽  
Cr 39 Detectors ◽  
Track Diameter

AbstractSolid state nuclear track detectors have been used for measuring axially emitted protons from a 2.2-kJ energy plasma focus device. The flux of the protons emerging out from the pinched plasma column of the plasma focus device has been found to saturate the CR-39 detectors. Aluminum filters have been used to avoid the saturation effect. By varying the aluminum filter thickness as well as the etching time of CR-39 detectors, proton tracks have been analyzed. Proton energy above 200 keV to about 1 MeV has been measured by using different thicknesses of aluminum filters. On increasing the etching hours, the most probable track diameter is found to be shifted from lower to higher values. The track number density decreases on increase of the filter thickness, whereas the track diameters increase linearly with respect to the etching time.

Backside Imaging and AFM Profiling of Tunnel Oxide, Poly 1, ONO and Poly 2 Layers on Flash Devices

2003 ◽  
Author(s):  
Kaushal Upadhyaya ◽  
Patrice W. Blacker
Keyword(s):  
Flash Memory ◽  
Gate Oxide ◽  
Floating Gate ◽  
Front Side ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Interconnects ◽  
Nitride Oxide ◽  
Failure Location ◽  
Scanning Electron

Abstract With increasing density of metal interconnects and shrinking device sizes with each process generation, there has been a growing interest in the Flash failure analysis (FA) community to approach the devices from the backside. Looking at the process layers like Tunnel Oxide, Poly 1 (floating gate), Oxide Nitride Oxide (ONO) and Poly 2 (control gate) from the backside provides useful information about failure location, failure type and failure mechanism which may be obscure from the front side. This work describes a novel combination of mechanical polishes and chemical etches to delayer Intel’s Flash memory devices from the backside to enable viewing of the bottom of the previously mentioned process layers. In addition to Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) has been attempted to gather more information about the surface details. This technique has been used successfully on Intel’s latest 90 nm flash process and has been verified on earlier process generations.

Research on Nuclear Heat Deposition Behavior in the Spallation Target of an Accelerator Driven Subcritical System

2012 ◽  
Author(s):  
S. Xiao ◽  
Y. Yang ◽  
Z. Zhou
Keyword(s):  
Incident Energy ◽  
Bragg Peak ◽  
Nuclear Reactions ◽  
Mechanical Design ◽  
Radiation Shielding ◽  
Proton Radiation ◽  
Spallation Target ◽  
Proton Source ◽  
Key Factor ◽  
Proton Incident

The power density distribution behavior of the ADS spallation target, which is a key factor in the thermal-hydraulic and mechanical design of the high-power ADS target, was investigated under different proton incident energy. A Chinese ADS conceptual design of spallation target was proposed in this paper. The deposition heat in the spallation target was calculated by MCNPX code. From the results, it was found that the Bragg peak phenomenon weakens as the proton source incident energy increases. Large Bragg peak was observed for proton incident energy below 500MeV, however for the proton source energy above 900MeV, Bragg peak phenomena was not obvious. Analysis on the nuclear reactions behavior and ionization process induced by source proton in the target was carried out to address this issue. Meanwhile, the results show that the proton leakage rate from the target, which is an important factor in proton radiation shielding, greatly depends on the proton range (penetration depth) under different incident energy. In order to stop or keep the protons in the target, the minimum axial length (in the incoming particles direction) of the target at a given proton source incident energy should be determined according to the corresponding proton range. The results of this paper will be useful to guide the design of spallation target of a reference ADS.

scholarly journals Interaction parameters of protons in Aluminum and Iron

2019 ◽  
Vol 24 (6) ◽  
pp. 104
Author(s):  
Sabah Mahmoud A.1 ◽  
Mohammed M. Asker2 ◽  
Zainb Sameen Ali2
Keyword(s):  
Atomic Number ◽  
Experimental Work ◽  
Incident Energy ◽  
Visual Basic ◽  
Stopping Power ◽  
Interaction Parameters ◽  
Empirical Equations ◽  
Slowing Down ◽  
Good Agreement ◽  
Proton Incident

The interactions parameters(including ,stopping power with orbital electrons, continues slowing down ranges approximation and square of screening angle)for slow protons(10-500)MeV in aluminum and iron elements were calculated by adopting  empirical  equations through  using  Visual Basic Studio program 2016. the  present study indicates that  the calculated parameters  show a linearity with  the atomic number (Z) and the proton incident energy of the absorber the comparison with the available  pervious experimental work gives a good agreement   http://dx.doi.org/10.25130/tjps.24.2019.115

Measurement of Dielectric Constant and Doping Concentration of a Cross-Sectioned Device by Quantitative Scanning Microwave Impedance Microscopy

2017 ◽  
Author(s):  
D. Iyer ◽  
A. Messinger ◽  
R. Crowder ◽  
Y. Zhang ◽  
O. Amster ◽  
...  
Keyword(s):  
Calibration Curve ◽  
Doping Concentration ◽  
Semiconductor Devices ◽  
Dielectric Materials ◽  
Device Structure ◽  
Force Microscopy ◽  
Quantitative Measurements ◽  
Atomic Force ◽  
N Doping ◽  
P Type

Abstract Scanning microwave impedance microscopy (sMIM) is an emerging technique that can provide detailed information beyond that of conventional scanning capacitance microscopy (SCM), and other electrical scanning probe microscopy (SPM) techniques, for the investigation and failure analysis (FA) of semiconductor devices. Integration of new dielectric materials at lower levels of the device structure with the need for quantification of dielectric and dopants in semiconductor devices with sub-micron spatial resolution pushes the practical boundaries of typical atomic force microscopy (AFM) electrical modes. sMIM can measure both linear and non-linear materials (insulators and doped semiconductors, respectively) simultaneously. sMIM has a linear response to log k (dielectric number) and log N (doping concentration) making it an ideal method for providing quantitative measurements of semiconductor devices over a large range of values. This work demonstrates an example of a practical application of sMIM for quantitative measurement of the dopant concentration profile in production semiconductor devices. A planar dopant calibration sample is used to calibrate the sMIM prior to performing the measurements on an “unknown” production device. We utilize nanoscale C-V data to establish a calibration curve for both n- and p-type carriers and apply the calibration curve to an “unknown” device, presenting the measurements in units of doping concentration.

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