Journal of Nuclear Physics, Material Sciences, Radiation and Applications 2019-03-20T14:29:02+0530 Dr. Sushil Kumar Open Journal Systems <p>The "<strong>Journal of Nuclear Physics, Material Sciences, Radiation and Applications</strong>” (<em>J. Nucl. Phy. Mat. Rad. A</em>) is a peer-reviewed, refereed, bi-annual open access Journal. One can freely access the journal’s article online at <a href=""></a></p> Radon in Workplaces the Urgent Need of New Measurements and Devices 2019-03-18T16:12:09+0530 L. Tommasino G. Espinosa <p>The existing passive radon monitors, their relative calibration facilities together with the past intercomparison exercises have been mission-oriented towards radon measurements in dwellings. These monitors have been successfully applied throughout the world for radon measurements in homes, characterized by temperatures in the range from 20 to 25°C and a relative humidity less than 50 R.H. A multitude of different problems may arise when these passive monitors are used in an environment other<br>than homes, such as in soil and in workplaces, where large humidity up to 100 RH and temperatures anywhere from 0°C to 40°C may be encountered. Under severe environmental conditions, different measurement errors may occur which have remained concealed to date. These errors may be caused by a drastic change of both the radon diffusivity through them and for the monitor housing respectively. permeation membranes or the radon absorption by the plastics, used for the track detector. For compliance with the assessment of the occupational exposures, it is necessary to eliminate all the possible sources of errors, which may be conducive to litigation. Another important shortcoming of the existing passive monitors is difficult to turn them on/off daily, as required for radon measurements in workplaces. Finally, most of the problems, listed above, can be solved by the exploitation of a new generation of passive monitors, known as Rn film-badges. These monitors are similar and often<br>identical to neutron film-badges, which have proved to be very successful throughout the world for the personnel neutron dosimetry. In particular, the present paper will describe the unique characteristics of these radon film badges, such as compactness, fast time response, any desired response sensitivity, simplicity in turning them on and off, etc.&nbsp;</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 L. Tommasino, G. Espinosa Redistribution of Nickel Ions Embedded within Indium Phosphide Via Low Energy Dual Ion Implantations 2019-03-19T12:07:18+0530 Daniel C. Jones Joshua M. Young Wickramaarachchige J. Lakshantha Satyabrata Singh Todd A. Byers Duncan L. Weathers Floyd D. McDaniel Bibhudutta Rout <p>Transition-metal doped Indium Phosphide (InP) has been studied over several decades for utilization in optoelectronics applications. Recently, interesting magnetic properties have been reported for metal clusters formed at different depths surrounded by a high quality InP lattice. In this work, we have reported accumulation of Ni atoms at various depths in InP via implantation of Ni<sup>-</sup> followed by H<sup>–</sup> and subsequently thermal annealing. Prior to the ion implantations, the ion implant depth profile was simulated using an ion-solid interaction code SDTrimSP, incorporating dynamic changes in the target matrix during ion implantation. Initially, 50 keV Ni<sup>-</sup> ions are implanted with a fluence of 2 × 10<sup>15</sup> atoms cm<sup>-2</sup>, with a simulated peak deposition profile approximately 42 nm from the surface. 50 keV H- ions are then implanted with a fluence of 1.5 × 10<sup>16</sup> atoms cm<sup>-2</sup>. The simulation result indicates that the H- creates damages with a peak defect center ~400 nm below the sample surface. The sample has been annealed at 450°C in an Ar rich environment for approximately 1hr. During the annealing, H vacates the lattice, and the formed nano-cavities act as trapping sites and a gettering effect for Ni diffusion into the substrate. The distribution of Ni atoms in InP samples are estimated by utilizing Rutherford Backscattering Spectrometry and X-ray Photoelectron Spectroscopy based depth profiling while sputtering the sample with Ar<sup>- </sup>ion beams. In the sample annealed after H implantation, the Ni was found to migrate to deeper depths of 125 nm than the initial end of range of 70 nm.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 Daniel C. Jones, Joshua M. Young, Wickramaarachchige J. Lakshantha, Satyabrata Singh, Todd A. Byers, Duncan L. Weathers, Floyd D. McDaniel, Bibhudutta Rout Spontaneous CP Violation Jarlskog Invariant in SM⊗S3 2019-03-19T15:41:27+0530 J. Montano-Peraza E. Barradas-Guevara O. Felix-Beltran E. Rodriguez-Jauregui <p>In our days, CP (Charge Parity) violation in the Standar Model of fundamental interactions still remains as an open problem. It is well known that explicit CP violation may be included by impossing complex Yukawa couplings in the Yukawa sector or complex Higgs couplings in exttended Higgs sectors with more than one Higgs field. It is desirable to have a fundamental CP violation theory, in that sence, we analyse the diferent secenarios for Spontaneous CP violation in an exteded Higgs model with three Higgs fields and a discrete flavour permutational symmetry S<sub>3</sub>. Spontaneous CP violation effects contribute to the Higgs mass matrix, as well as, up and down quark mass matrices. This complex quark mass matrices allow us to study the conditions for a non-vanishing Jarlskog invariant J which provides a necessary and sufficient contribution for a spontaneous CPV coming from SM ⊗ S<sub>3</sub></p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 J. Montano-Peraza, E. Barradas-Guevara, O. Felix-Beltran, E. Rodriguez-Jauregui Signal of h → µτ, ττ in ν2HDM⊕S3 2019-03-19T12:14:02+0530 E. Barradas Guevara F. Cazarez-Bush O. Felix-Beltran F. Gonzalez-Canales <p>Nowadays in particle physics, the exploration of the flavor physics through the Higgs boson phenomenology is one of the main goals in the field. In particular we are interested in the Lepton Flavour Violation (LFV) processes. In this work, we explore the processes h → µτ, ττ in the theoretical framework of a flavored extension of the Standard Model, which has two Higgs fields and the horizontal permutation symmetry S<sub>3</sub> imposed in the Yukawa sector, this extension is called ν2HDM⊗S<sub>3</sub>.We obtain the couplings <span class="ILfuVd">ϕ</span>µτ, ττ as well as Br(h → µτ) in function of the model parameters in function of the model parameters, which are constricted by means the experimental results of <span class="ILfuVd">ϕ</span><sub>SM</sub> → µτ reported in the literature.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 E. Barradas Guevara, F. Cazarez-Bush, O. Felix-Beltran, F. Gonzalez-Canales Dependence on the Identification of the Scale Energy Parameter Q2 in the Quark Distribution Functions for a DIS Production of Za 2019-03-19T14:07:28+0530 M. Gómez-Bock W. Gonzalez L. López Lozano S. Rosado-Navarro A. Rosado <p>We discuss the Z-production in a DIS (Deep Inelastic Scattering) process e + p → e + Z + X using the Parton Model, within the context of the Standard Model. In contrast with deep inelastic eP-scattering (e + p → e + X), where the choice of Q<sup>2</sup> , as the transferred momentum squared, is unambiguous; whereas in the case of boson production , the transferred momentum squared, at quark level, depends on the reaction mechanism (where is the EW interaction taking place). We suggest a proposal based on kinematics of the process considered and the usual criterion for Q<sup>2</sup> , which leads to a simple and practical prescription to calculate Z-production via ep-DIS. We also introduce different options in order to perform the convolution of the parton distribution functions (PDFs) and the scattering amplitude of the quark processes. Our aim in this work is to analyze and show how large could be the dependence of the total cross section rates on different possible prescriptions used for the identification of the scale energy parameter Q<sup>2</sup> . We present results for the total cross section as a function of the total energy <span class="ILfuVd"><strong>√</strong>s</span> of the system ep, in the range 300 <span class="ILfuVd">&lt;</span><span class="ILfuVd"><strong>√</strong>s</span> <span class="ILfuVd">≤</span> 1300 GeV</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 M. Gómez-Bock, W. Gonzalez, L. López Lozano, S. Rosado-Navarro, A. Rosado Annihilation of Dipolar Dark Matter: χχ→γγ 2019-03-19T14:25:39+0530 E. Barradas-Guevara J. L. Díaz-Cruz O. G. Félix Beltrán C. Arellano Celiz <p>In this work we study the annihilation of dark matter, considering it as a neutral particle with magnetic and/or electric moments not null. The calculation of the effective section of the process <span id="r_i_greek_letter_forms__d20e3557" class="ph"><span class="ph Math"><em class="ph i">χ</em></span></span><sub><span id="r_i_greek_letter_forms__d20e3596" class="ph"></span><span id="r_i_greek_letter_forms__d20e3596" class="ph"><img class="image" src="" alt="chi bar"></span></sub>→γγ → is made starting from a general form of coupling <span id="r_i_greek_letter_forms__d20e3557" class="ph"><span class="ph Math"><em class="ph i">χ</em></span></span><sub><span id="r_i_greek_letter_forms__d20e3596" class="ph"><img class="image" src="" alt="chi bar"></span></sub>γ in the framework of an extension of the Standard Model. We found, when taking into account an annihilation of DDM-antiDDM to monoenergetic photons, that for small masses, m<span id="r_i_greek_letter_forms__d20e3596" class="ph"><img class="image" src="" alt="chi bar"></span> ≤ 0 GeV, an electric dipole moment ~10<sup>–6</sup> e cm is required to satisfy the current residual density, while for the range of greater sensitivity of HAWC, 10 TeV &lt; E<sub>g</sub> &lt; 20 TeV, the electrical dipole moment must be of the order of 10<sup>–8</sup> e cm.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 E. Barradas-Guevara, J. L. Díaz-Cruz, O. G. Félix Beltrán, C. Arellano Celiz Temperature Effects in the Composition of Metal Halide Perovskite thin Films 2019-03-19T15:35:12+0530 M. Castro-Colin L. Banuelos C. Diaz-Moreno D. Hodges E. Ramirez-Homs D. Korolkov N. Sharmin J. A. Lopez <p>Metal halide perovskites have shown to be a structure with great promise as an efficient photovoltaic, but at the same time it is affected by instability problems that degrade their performance. Degradation mechanisms vary with temperature, moisture, oxidation, and energy conversion during light exposure. We study performance loss due to temperature by probing diffusion of elemental composition across the thickness of films produced by spin coating and for temperatures ranging from 20 to 200°C. X-ray reflectivity was used to identify the electron density, composition, and quality of the films, aided with X-ray fluorescence and X-ray photoelectron spectroscopy studies to obtain information about degradation of the organic phase of the films.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 M. Castro-Colin, L. Banuelos, C. Diaz-Moreno, D. Hodges, E. Ramirez-Homs, D. Korolkov, N. Sharmin, J. A. Lopez Analysis of the Energy Deposit in the Air by Radiation of Alpha Particles Emitted by the Water of a Spring Through the Geant4 Software 2019-03-19T16:14:17+0530 A Lima Flores R Palomino-Merino E Moreno-Barbosa JN Domínguez-Kondo VM Castaño AC Chavarría Sánchez JI Golzarri G Espinosa <p>This work presents the development of an analysis of the potential radiological risk generated by alpha particles emitted by radon-222, content in a spring water, for the population that usually swims in the place and for the people who live near this spring. This spring is located in the state of Puebla. Several measurements in the water of this place by researchers from IF-UNAM showed that it contains an average radon concentration level of 70 Bq/m<sup>3</sup>. To evaluate this radiological risk, it has been developed a computational simulation to know the area and the height where the alpha particles deposit their energy to the medium, as well as the amount of energy that they transfer. This simulation was developed in the Geant4 scientific software and the calculations were executed in the supercomputer of the Laboratorio Nacional de Supercomputo del Sureste de Mexico of the BUAP. The results show that the energy deposit occurs within the superficial limits of the spring, between 7 and 8 meters high. This deposited is not only by the alpha particles, but also by the secondary particles that are generated by the interaction of alpha particles with the environment. Based on these results, it is confirmed that there is no radiological risk by energy deposit by alpha particles for the people.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 A Lima Flores, R Palomino-Merino, E Moreno-Barbosa, JN Domínguez-Kondo, VM Castaño, AC Chavarría Sánchez, JI Golzarri, G Espinosa Effect of the Target Size in the Calculation of the Energy Deposited Using PENELOPE Code 2019-03-20T10:12:52+0530 B. Leal-Acevedo P.G. Reyes-Romero F. Castillo I. Gamboadebuen <p>The specific and linear energy was calculated in target sizes of 10 µm, 5 µm, 1 µm, 60 nm, 40nm and 20 nm by taking into account the contribution of the primary photon beams and the electrons generated by them in LiF: Mg, Ti (TLD-100). The simulations were carried out by the code PENELOPE 2011. Using different histories of primary particles, for each energy beams the mean deposited energy is the same, but to achieve a statistical deviation lower than 1% the value of 108 was fixed. We find that setting the values C1 = 0.1 C2 = 0.1 and W<sub>cc</sub> = W<sub>cr</sub> = 50 eV the time of simulation decreases around the 25%. The uncertainties (1 SD) in the specific energy increases with energy for all target sizes and decreases with target size, with values from 1.7 to 94% for 20 nm and between 0.1 and 0.8% for 10 µm. As expected, the specific and linear energies decrease with target size but not in a geometrical behavior.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 B. Leal-Acevedo, P.G. Reyes-Romero, F. Castillo, I. Gamboadebuen Synthesis of MgB4O7:Dy3+ and Thermoluminescent Characteristics at Low Doses of Beta Radiation 2019-03-20T10:59:26+0530 O Legorreta-Alba E Cruz-Zaragoza D Díaz J Marcazzó <p>The synthesis and thermoluminescent characteristics of dysprosium-doped MgB<sub>4</sub>O<sub>7</sub> are analyzed. The phosphor at different concentrations (0, 0.1, 0.5, 1, 2 and 4 mol%) of the dopant was prepared by the solution-assisted method. The magnesium borate compound was confirmed by X-ray diffraction. The annealing and dopant concentrations effects on the crystalline matrix were investigated. The highest thermoluminescent sensitivity was found with 450°C of annealing temperature and at high Dy<sup>3+</sup> concentration too. The un-doped MgB<sub>4</sub>O<sub>7</sub> phosphor shows a broad glow curve which peaked at 199°C and about 306 °C. Introducing Dy<sup>3+</sup> dopant in the matrix that behavior was strongly changed. The wide glow curve shows three glow peaks; two small shoulders at 124 and 195 °C, and a highest peak between 323 and 336 °C temperature range. A large linear dose-response (5 – 2000 mGy) beta dose was obtained. The complex glow curves were deconvolved and the kinetics parameters were determined considering the general order kinetics model.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 O Legorreta-Alba, E Cruz-Zaragoza, D Díaz, J Marcazzó Study of Solid-State Radiolysis of Behenic, Fumaric, and Sebacic Acids for their Possible Use as Gamma Dosimeters Measured Via ATR-FT-IR Spectroscopy 2019-03-20T11:14:26+0530 J. Cruz-Castañeda A. L. Meléndez-López A. Heredia S. Ramosbernal A. Negrón-Mendoza <p>The intensive use of ionizing radiation has promoted the constant investigation of adequate dosimetric systems in the measurement of doses applied in irradiated products. The objective of this work is to propose gamma dosimetric systems, using carboxylic acids in a solid state and measuring the change via infrared spectroscopy (carboxylic acid/ ATR-FT-IR1). We worked with three systems: (1) behenic acid/ATR-FT-IR, (2) sebacic acid/ATR-FT-IR, and (3) fumaric acid/ATR-FT-IR. The change in absorbance corresponding to the stretching vibration frequency of the carbonyl group to the absorbed dose (in the range of kGy) was measured. The results showed that the acid/ATR-FT-IR systems have a linear response with respect to the absorbed dose, for behenic acid/ATR-FT-IR from 0 to 122 kGy, for ATR-FT-IR sebacic acid from 0 to 61 kGy, and for fumaric acid/ATR-FT-IR from 0 to 34 kGy. The results indicated that the linear response of the absorbance dose in the three systems allows us to continue studying other variables to be able to propose them as chemical dosimeters.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 J. Cruz-Castañeda, A. L. Meléndez-López, A. Heredia, S. Ramosbernal, A. Negrón-Mendoza Gamma Dosimetry Using Some Dyes in Organic Solvents Solutions at 295 and 77 K 2019-03-20T11:36:07+0530 A L Melendez-Lopez A Paredes-Arriaga J Cruz-Castaneda A Negron-Mendoza S Ramos-Bernal M Colin-Garcia A Heredia <p>The aim of this work is to study the behavior under irradiation of different dyes (green malachite, methyl orange, red cresol, and bromothymol blue) in organic solvents (acetone and methanol) at different gamma doses and different temperatures to propose them as possible dosimeters for lowtemperature applications. For this purpose, organic dissolutions were irradiated with gamma rays in the kiloGray (kGy) range at 77 and 295 K, and the color bleaching of the solutions was followed spectrophotometrically (UV-Vis range). The response curves at different temperatures show the linear range interval from 10 to 40 kGy with correlation coefficients of 0.999 and 0.998 for some systems. This is the main reason to continue carrying out studies that allow the proposal of these systems as chemical dosimeters.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 A L Melendez-Lopez, A Paredes-Arriaga, J Cruz-Castaneda, A Negron-Mendoza, S Ramos-Bernal, M Colin-Garcia, A Heredia Agent Based Model of the Cytosine Radiation Induced Reaction 2019-03-20T12:23:04+0530 A L Rivera S Ramos-Beltran A Paredes-Arriaga A Negron-Mendoza <p>The stability of cytosine in aqueous solution was studied in the laboratory, simulating prebiotic conditions and using gamma radiation as an energy source, to describe cytosine behavior under radiation. For a better understanding of the radiation-induced processes, we proposed a mathematical model that considers chemical reactions as nonlinear ordinary differential equations. The radiolysis can be computationally simulated by an agent-based model, wherein each chemical species involved is considered to be an agent that can interact with other species with known reaction rates. The radiation is contemplated as a factor that promotes product formation/destruction, and the temperature determines the diffusion speed of the agents. With this model, we reproduce the changes in cytosine concentration obtained in the laboratory under different irradiation conditions.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 A L Rivera, S Ramos-Beltran, A Paredes-Arriaga, A Negron-Mendoza Ionizing Radiation, an Instrument in Chemical Evolution Studies: Scope and Perspectives 2019-03-20T14:21:31+0530 E Y Aguilar-Ovando A Negron-Mendoza M L Ramirez-Vazquez R C Acosta-Fernandez <p>The study of synthesis and stability of molecules in different environments it’s been part of chemistry evolution and origin of life studies for more than 70 years. Various kinds of ionizing radiation have been analyzed as possible sources of energy for the transformations undergone by the first organic molecules. Now experimental and computational simulation approaches continue with different groups of organic molecules, in search for more information that help us to understand and reconstruct somehow the mechanisms that toke place on early Earth and space. In that line, this paper presents first approach of keto acids stability to ionizing radiation, an interesting group of molecules involved in the Krebs cycle and glycolysis. Preliminary results obtained by HPLC/UV analysis of irradiating aqueous solutions of 5 keto acids ranging from 3 to 6 carbons with a <sup>60</sup>Co gamma ray source, using doses up to 53 kGy, show different stabilities and a general tendency of shifting the keto-enol equilibrium to the enol tautomer before decomposition.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 E Y Aguilar-Ovando, A Negron-Mendoza, M L Ramirez-Vazquez, R C Acosta-Fernandez Laser Radiation Effects on Adenine 2019-03-20T14:24:23+0530 L.X. Hallado J.C. Poveda E. Prieto A. Guerrero I. Álvarez C. Cisneros <p>Laser interaction whit the gas phase nucleobase adenine is studied. A linear TOF mass spectrometer is utilized for measurements that require high mass resolution, high sensitivity, and sufficient ion yields of low mass fragment cations. The ion mass spectra are discussed at different laser energy intensities and two temperatures. In contrast to previous studies a number light ion is present in the mass spectra. The ion formation curves for 23 different ions are measured for the laser energy range from about 10<sup>9</sup> to 10<sup>10</sup> W cm<sup>–2</sup> and masses between 1 and 43 besides mass 57 which was present in the mass spectra and will be discuss. Data were taken heating the sample at 235<sup>o</sup> C. The number of 355nm absorbed photons was calculated accordingly to Keldysh theory and similar results were found using adenine -Ar mixture. Our results are compared with those reported formed by protons, electrons or multiple charged ions interactions. Different ions were found indicating the possible effect of multiphoton absorption.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 L.X. Hallado, J.C. Poveda, E. Prieto, A. Guerrero, I. Álvarez, C. Cisneros In vitro Study of the Survival, Reproduction and Morphology of Daphnia pulicaria irradiated with a Low Energy Laser 2019-03-20T14:26:34+0530 F. Zaldivar J. Montoya S. Gonzalez L.A. Mandujano J. F. Mendez-Sanchez L. Romero J. Mulia M. Paulin D. Osorio-Gonzalez <p>Daphnia is a genus of crustaceans that is representative of freshwater communities. The species exhibit a high sensitivity to a wide range of toxic compounds so that they have been used internationally as biomonitors in toxicity tests to evaluate ecosystem conditions such as water quality. It is also a model genus in genetics, epigenetics and reproductive ecology. In this work, we used Daphnia pulicaria as a model to measure the effects of low-energy laser irradiation on survival, reproduction, and morphology variables of parental organisms and their offspring. We used (1) a single clone line of organisms to eliminate interindividual genetic variability; (2) individuals from more than 50 generations after the clone line was established, and offspring from the third brood onwards to dissipate maternal and epigenetic effects, and (3) neonates, those individuals of the species that have less than 48 hours of life, because they are the most sensitive stage to optical stimuli. We analyzed number of deaths, longevity, age at first reproduction, number of offspring per week, number of total offspring during all their life cycle, body size, size of the antennules, and length of the apical spine of the 4th and 5th brood of the irradiated individuals, who were exposed to a blue laser stimulus of 405 nm for 25 minutes with a power of 40 mW at a distance of 50 cm, compared to those of the control (non-irradiated) group.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 F. Zaldivar, J. Montoya, S. Gonzalez, L.A. Mandujano, J. F. Mendez-Sanchez, L. Romero, J. Mulia, M. Paulin, D. Osorio-Gonzalez In silico Analysis of the Structural Properties of PSMA and its Energetic Relationship with Zn as Cofactor 2019-03-20T14:29:02+0530 M.A. Fuentes L. A. Mandujano R. López L.R. Guarneros E. Azorín D. Osorio-González <p>Revised: July 05, 2018 Accepted: July 20, 2018<br>Published online: August 6, 2018<br>The prostate-specific membrane antigen (PSMA) is a 100 kDa type II transmembrane glycoprotein with enzymatic activity similar to the family of zinc-dependent exopeptidases. This protein is of great medical and pharmacological interest as overexpression in prostate cells is related to the progression of prostate cancer; therefore, it represents an important target for the design of radiopharmaceuticals. The presence of two Zn<sup>2+</sup> ions in the active site is crucial to the enzymatic activity and the design of high-affinity inhibitors. The amino acid residues coordinating these ions are highly conserved in PSMA orthologs from plants to mammals, and site-mutagenesis assays of these residues show a loss of enzymatic function or reduction of the kinetic parameters. In the present work, we performed molecular dynamics simulation of PSMA with the purpose of characterizing it energetically and structurally. We elucidated the differences of PSMA with its two Zn<sup>+2</sup> ions as cofactors and without them in the free energy profile, and in four structural parameters: root mean square deviations and root mean square fluctuations by atom and amino acid residue, radius of gyration, and solvent accessible surface area.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 M.A. Fuentes, L. A. Mandujano, R. López, L.R. Guarneros, E. Azorín, D. Osorio-González Jung’s Theorem Applied in Nuclear Track Methodology 2019-03-19T15:47:51+0530 G. Chacin L. Sajo-Bohus J.J. Rojas Hancco G. Espinosa <p>Nuclear track density provides accelerator beam imaging and diagnostic employing CR-39 passive detectors. Counting charged particles related tracks by automated reading systems depend on the accuracy of microscope field view other that chemical etching procedure and frequency of overlapped tracks. The study, to propose a method to determined track density for analyser optical field view not calibrated. The approach Jungs’ theorem, provides the area value based on the maximum distance for two selected etched tracks. Results show that the new method has its importance when microscope field view calibration is not available with precision for accelerator beam diagnostics.</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 G. Chacin, L. Sajo-Bohus, J.J. Rojas Hancco, G. Espinosa Improvements to the X-ray Spectrometer at the Aerosol Laboratory, Instituto de Física, UNAM 2019-03-19T16:11:57+0530 L V Mejía-Ponce A E Hernández-López S Reynoso-Cruces J C Pineda J A Mendoza-Flores J Miranda <p>Due to the demands of better (accurate and precise) analytical results using X-ray Fluorescence (XRF) at the Aerosol Laboratory, Instituto de Física, UNAM, it was necessary to carry out improvements in instrumentation and analytical procedures in the x-ray spectrometer located in this facility. A new turbomolecular vacuum system was installed, which allows reaching the working pressure in a shorter time. Characteristic x-rays are registered with a Silicon Drift Detector, or SDD, (8 mm thick Be window, 140 eV at 5.9 keV resolution), working directly in a high-vacuum, permitting the detection of x-rays with energies as low as 1 keV (Na Ka) and higher counting rates than in the past. Due to the interference produced by the Rh L x-rays emitted by the tube normally used for atmospheric and food analysis with Cl K x-rays, another tube with a W anode was mounted in the spectrometer to avoid this interference, with the possibility to select operation with any of these tubes. Examples of applications in atmospheric aerosols and other samples are presented, to demonstrate the enhanced function of the spectrometer. Other future modifications are also explained.</p> 2019-03-19T16:11:57+0530 Copyright (c) 2018 L V Mejía-Ponce, A E Hernández-López, S Reynoso-Cruces, J C Pineda, J A Mendoza-Flores, J Miranda Dose Calibration and Track Diameter Distribution for 241Am-Be Neutron Source, Using CR-39 Nuclear Track Methodology 2019-03-20T11:17:56+0530 J. S. Bogard J. I. Golzarri G. Espinosa <p>Revised: July 07, 018 Accepted: July 21, 2018<br>Published online: August 6, 2018<br>In neutron detection, the more common method is using electronic instrumentation associate with Bonner spheres, however, currently the Nuclear Tracks Methodology (NTM) is coming popular because of the simplicity, flexibility in size of the detector, no requirement for sophisticated instrumentation and installation, and low cost. In this work, a preliminary result of the dose calibration and track diameter distribution of Americium-Beryllium (<sup>241</sup>Am-Be) source using Nuclear Track Methodology is presented. As material detector, CR-39 polycarbonate, cut in 1.8 × 0.9 cm<sup>2</sup> chips was chosen, and two step chemical etchings after neutron exposure was used to develop the tracks. The irradiations were made in environmental normal conditions, in the ORNL neutron calibration facilities. The CR-39 chips were placed in a phantom, with 3mm plastic (Lexan) sheet in between the source and detectors to increase the proton generation. The total track density and track diameter distribution was performing in a Counting and Analysis Digital Image System (CADIS), developed at the Institute of Physics of the University of Mexico UNAM. The results are compared with a standard survey instrument and energy reference spectra of the International Atomic Energy Agency (IAEA).</p> 2018-08-06T00:00:00+0530 Copyright (c) 2018 J. S. Bogard, J. I. Golzarri, G. Espinosa