Characterization of neutrons from a thick target 9Be(p, n) reaction by multiple foil activation technique for practical applications: measurement of integral cross sections and their comparison with integrated data from data files

2014 ◽  
Vol 102 (5) ◽  
Author(s):  
Md. Shuza Uddin ◽  
Kyo Kume ◽  
Takushi Takata ◽  
Takashi Hasegawa
Keyword(s):  
Cross Sections ◽  
Thick Target ◽  
Activation Technique ◽  
Practical Applications ◽  
Foil Activation ◽  
Data Files

scholarly journals Activation cross sections of gamma-emitters produced in deuteron induced reactions on $${}^{{209}}$$Bi up to 50 MeV

2021 ◽  
Vol 57 (7) ◽  
Author(s):  
F. Tárkányi ◽  
S. Takács ◽  
F. Ditrói ◽  
Z. Szűcs ◽  
K. Brezovcsik ◽  
...  
Keyword(s):  
Cross Sections ◽  
Thick Target ◽  
Activation Technique ◽  
Model Calculations ◽  
Decay Products ◽  
Foil Activation ◽  
On Line ◽  
Stacked Foil Activation Technique ◽  
D Model ◽  
Activation Cross Sections

AbstractDeuteron induced reactions on natural bismuth targets were investigated with the stacked foil activation technique up to 50 MeV. Excitation functions for the reactions $$^{\mathrm {209}}$$ 209 Bi(d,xn)$$^{\mathrm {207,206,205}}$$ 207 , 206 , 205 Po, Bi(d,x)$$^{\mathrm {207,205}}$$ 207 , 205 Bi and $$^{\mathrm {209}}$$ 209 Bi(d,x)$$^{\mathrm {203}}$$ 203 Pb obtained from gamma-spectra of decay products were compared with the results of our ALICE-D and EMPIRE-D model calculations, with the result of TALYS code taken from TENDL-2019 on-line library and the results of the only measurement performed earlier. Thick target yields were deduced from the fitted experimental cross sections.

scholarly journals Activation cross section data of deuteron induced nuclear reactions on rubidium up to 50 MeV

2021 ◽  
Vol 57 (1) ◽  
Author(s):  
Ferenc Tárkányi ◽  
Alex Hermanne ◽  
Ferenc Ditrói ◽  
Sándor Takács ◽  
Anatolij V. Ignatyuk ◽  
...  
Keyword(s):  
Cross Sections ◽  
Gamma Ray ◽  
Nuclear Reactions ◽  
Thick Target ◽  
Gamma Ray Spectrometry ◽  
Activation Cross Section ◽  
Experimental Database ◽  
Practical Applications ◽  
Section Data ◽  
First Time

AbstractActivation cross sections of the $$^{\mathrm {nat}}\hbox {Rb (d,xn)}^{87\mathrm {m,85m,85g,83,82}}\hbox {Sr}$$ nat Rb (d,xn) 87 m , 85 m , 85 g , 83 , 82 Sr , $$^{\mathrm {nat}}\hbox {Rb(d,x)}^{\mathrm {86,84,83,82m}}\hbox {Rb}$$ nat Rb(d,x) 86 , 84 , 83 , 82 m Rb and $$^{\mathrm {nat}}\hbox {Rb(d,x)}^{85\mathrm {m}}\hbox {Kr}$$ nat Rb(d,x) 85 m Kr nuclear reactions have been measured for the first time through an activation method combining the stacked foil irradiation technique and gamma-ray spectrometry. The provided cross sections from the present investigation are all new, in such a way contribute to the completeness of the experimental database. The experimental cross sections were compared with the theoretical prediction in the TENDL-2019 TALYS based library and with our calculation using ALICE-D and EMPIRE-D model codes in order the improve their predictivity. Thick target production yields were calculated form the new cross sections for all investigated radioisotopes. Practical applications of the results are shortly discussed.

scholarly journals Quantification of the Enhancement Factor in Surface-Enhanced Raman Scattering

2021 ◽  
Author(s):  
◽  
Evan Blackie
Keyword(s):  
Cross Section ◽  
Single Molecule ◽  
Cross Sections ◽  
Enhancement Factor ◽  
Density Functional ◽  
Practical Applications ◽  
Surface Enhanced Raman ◽  
Scattering Volume ◽  
Rhodamine Dye

<p>This thesis presents a rigorous stepwise methodology towards the accurate measurement and quantification of the SERS enhancement factor (EF), the key parameter in describing the SERS effect. The work represents, we believe, a successful attempt to resolve some of the inconsistencies in the literature and to refocus the field by emphasizing the importance of consistent definitions and rigorous quantification to elucidate matters of fundamental importance in SERS. The success in our approach is that it combines careful experimental measurements upon a sound theoretical framework, and utilizes a 'toolbox' of techniques developed in recent years, such as bi-analyte SERS (BiASERS) techniques for single-molecule (SM) detection, and isotopic editing. In experimental work, we measure the bare Raman cross-sections of five common probes used in SERS as a first step in measuring the analytical enhancement factor (AEF) and single-molecule enhancement factor (SMEF). The methodology in measuring these EFs involved the use of a reference standard of known cross-section along with a careful characterization of the scattering volume through beam profiling experiments. As a guide to validating the reference cross-section we make extensive use of density functional theory (DFT) calculations to obtain estimates for the intrinsic Raman cross-sections of small, non-resonant probes. The results of this work showed that previous upper limits for the EF reported in the literature of 1014 were based on a faulty normalization of the EF. In fact, EFs of 108 were sufficient to see single molecules, which is much lower than previously expected; under optimum conditions, even lower EFs, possibly down to 105 could be sufficient for the SM detection of resonant probes. As a valuable extension of BiASERS, we elaborate on the synthesis of isotopic analogues of a rhodamine dye as ideal partners for SM experiments. The synthesis and definitive characterization of these probes enable their use in an experiment to determine the SM regime in a liquid colloidal sample. Isotopically edited dyes such as these, in combination with the methodologies of EF quantification outlined herein, set the standard for those interested in accurate quantification of the SERS effect. This approach is useful in terms of both basic theoretical questions and applications such as the effective comparison of SERS substrates. Finally, we extend the techniques developed over the thesis to a long-standing and largely unresolved question in SERS: What is the minimum intrinsic Raman cross-section that can be measured as a single molecule in standard SERS conditions. In this work, we explore the SM detection non-resonant probes, which are the molecules of interest for many practical applications such as forensics and biological assays. Specifically, we demonstrate the successful SM detection of isotopically edited adenine probes.</p>

scholarly journals Quantification of the Enhancement Factor in Surface-Enhanced Raman Scattering

2021 ◽  
Author(s):  
◽  
Evan Blackie
Keyword(s):  
Cross Section ◽  
Single Molecule ◽  
Cross Sections ◽  
Enhancement Factor ◽  
Density Functional ◽  
Practical Applications ◽  
Surface Enhanced Raman ◽  
Scattering Volume ◽  
Rhodamine Dye

<p>This thesis presents a rigorous stepwise methodology towards the accurate measurement and quantification of the SERS enhancement factor (EF), the key parameter in describing the SERS effect. The work represents, we believe, a successful attempt to resolve some of the inconsistencies in the literature and to refocus the field by emphasizing the importance of consistent definitions and rigorous quantification to elucidate matters of fundamental importance in SERS. The success in our approach is that it combines careful experimental measurements upon a sound theoretical framework, and utilizes a 'toolbox' of techniques developed in recent years, such as bi-analyte SERS (BiASERS) techniques for single-molecule (SM) detection, and isotopic editing. In experimental work, we measure the bare Raman cross-sections of five common probes used in SERS as a first step in measuring the analytical enhancement factor (AEF) and single-molecule enhancement factor (SMEF). The methodology in measuring these EFs involved the use of a reference standard of known cross-section along with a careful characterization of the scattering volume through beam profiling experiments. As a guide to validating the reference cross-section we make extensive use of density functional theory (DFT) calculations to obtain estimates for the intrinsic Raman cross-sections of small, non-resonant probes. The results of this work showed that previous upper limits for the EF reported in the literature of 1014 were based on a faulty normalization of the EF. In fact, EFs of 108 were sufficient to see single molecules, which is much lower than previously expected; under optimum conditions, even lower EFs, possibly down to 105 could be sufficient for the SM detection of resonant probes. As a valuable extension of BiASERS, we elaborate on the synthesis of isotopic analogues of a rhodamine dye as ideal partners for SM experiments. The synthesis and definitive characterization of these probes enable their use in an experiment to determine the SM regime in a liquid colloidal sample. Isotopically edited dyes such as these, in combination with the methodologies of EF quantification outlined herein, set the standard for those interested in accurate quantification of the SERS effect. This approach is useful in terms of both basic theoretical questions and applications such as the effective comparison of SERS substrates. Finally, we extend the techniques developed over the thesis to a long-standing and largely unresolved question in SERS: What is the minimum intrinsic Raman cross-section that can be measured as a single molecule in standard SERS conditions. In this work, we explore the SM detection non-resonant probes, which are the molecules of interest for many practical applications such as forensics and biological assays. Specifically, we demonstrate the successful SM detection of isotopically edited adenine probes.</p>

scholarly journals Influence of parasitic neutrons to the 176Hf(n,2n)175Hf reaction cross section

2019 ◽  
Vol 18 ◽  
pp. 83
Author(s):  
R. Vlastou ◽  
M. Kokkoris ◽  
M. Serris ◽  
M. Lambrou ◽  
L. Sofokleous ◽  
...  
Keyword(s):  
Cross Sections ◽  
Reaction Cross Section ◽  
Liquid Scintillator ◽  
Reaction Cross ◽  
Energy Spectra ◽  
Recoil Energy ◽  
Activation Technique ◽  
Tandem Accelerator ◽  
Analysis Technique ◽  
Foil Activation

Cross sections for 176Hf(n,2n)175Hf reaction have been measured at the VdG Tandem accelerator of NCSR \Demokritos", in the neutron energy region from 8.80 to 11.02 MeV, using the activation technique. In order to account for the contamination of the 176Hf(n,2n)175Hf by the 174Hf(n,γ)175Hf reaction activated by the presence of parasitic neutrons, an experimental method has been developed based on the influence of the parasitic neutrons in the case of the (n,2n) and (n,γ) reactions on 197Au. The results were found to be consistent with the energy spectrum of the neutron beam which has been studied by means of the multiple foil activation analysis technique as well as by a liquid scintillator BC501A detector and subsequent deconvolution of its recoil energy spectra.

scholarly journals Experimental study of the 197Au(n,2n) reaction cross section

2019 ◽  
Vol 17 ◽  
pp. 9
Author(s):  
A. Tsinganis ◽  
M. Kokkoris ◽  
A. Lagoyannis ◽  
E. Mara ◽  
C. T. Papadopoulos ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Isomeric State ◽  
Reaction Cross Section ◽  
Reaction Cross ◽  
Activation Technique ◽  
Incident Neutron ◽  
Mcnp Code ◽  
Foil Activation ◽  
24Na Reaction

In the present work, the 197Au(n,2n) reaction cross section is experimentally determined relative to the 27Al(n,α)24Na reaction at incident neutron energies of 9.0 to 10.5 MeV by means of the activation technique. The quasi-monoenergetic fast neutron beam was produced via the 2H(d,n)3He reaction at the 5.5 MV Tandem Van de Graaff accelerator at the NCSR “Demokritos” and was studied to determine the contribution of background “parasitic” neutrons using the multiple foil activation technique and the SULSA unfolding code. The cross sections for the population of the second isomeric state (12−) of 196Au and the sum of the ground (2−) and first isomeric state (5−) population cross sections were independently determined. Auxiliary Monte Carlo simulations were performed with the MCNP code.

scholarly journals CHARACTERIZATION OF 241AM-BE NEUTRON SOURCE USING THRESHOLD FOIL ACTIVATION TECHNIQUE

2019 ◽  
Vol 30 (1) ◽  
pp. 48-53
Author(s):  
N. Kotb ◽  
M. Tohamy ◽  
A. Solieman ◽  
T. El - Zakla ◽  
T. Amer ◽  
...  
Keyword(s):  
Neutron Source ◽  
Activation Technique ◽  
Foil Activation

Characterization of intergranular cuprous oxide in polycrystalline YBa2Cu3O7-x

1988 ◽  
Vol 46 ◽  
pp. 880-881
Author(s):  
Bradley L. Thiel ◽  
Chan Han R. P. ◽  
Kurosky L. C. Hutter ◽  
I. A. Aksay ◽  
Mehmet Sarikaya
Keyword(s):  
Grain Boundary ◽  
Cuprous Oxide ◽  
Room Temperature ◽  
Boundary Phase ◽  
Spectroscopic Techniques ◽  
Transition Width ◽  
Practical Applications ◽  
Thin Foils ◽  
Superconducting Oxides

The identification of extraneous phases is important in understanding of high Tc superconducting oxides. The spectroscopic techniques commonly used in determining the origin of superconductivity (such as RAMAN, XPS, AES, and EXAFS) are surface-sensitive. Hence a grain boundary phase several nanometers thick could produce irrelevant spectroscopic results and cause erroneous conclusions. The intergranular phases present a major technological consideration for practical applications. In this communication we report the identification of a Cu2O grain boundary phase which forms during the sintering of YBa2Cu3O7-x (1:2:3 compound).Samples are prepared using a mixture of Y2O3. CuO, and BaO2 powders dispersed in ethanol for complete mixing. The pellets pressed at 20,000 psi are heated to 950°C at a rate of 5°C per min, held for 1 hr, and cooled at 1°C per min to room temperature. The samples show a Tc of 91K with a transition width of 2K. In order to prevent damage, a low temperature stage is used in milling to prepare thin foils which are then observed, using a liquid nitrogen holder, in a Philips 430T at 300 kV.

Processing and characterization of YBa2Cu3O7−x/Ag composites

1990 ◽  
Vol 48 (4) ◽  
pp. 46-47
Author(s):  
Jafar Javadpour ◽  
Bradley L. Thiel ◽  
Sarikaya Mehmet ◽  
Ilhan A. Aksay
Keyword(s):  
Composite System ◽  
Precursor Solution ◽  
Microstructural Development ◽  
Superconducting Properties ◽  
Practical Applications ◽  
Nitrate Precursor ◽  
Cold Pressed ◽  
Tape Cast ◽  
Composite Samples

Practical applications of bulk YBa2Cu3O7−x materials have been limited because of their inadequate critical current density (jc) and poor mechanical properties. Several recent reports have indicated that the addition of Ag to the YBa2Cu3O7−x system is beneficial in improving both mechanical and superconducting properties. However, detailed studies concerning the effect of Ag on the microstructural development of the cermet system have been lacking. Here, we present some observations on the microstructural evolution in the YBa2Cu3O7−x/Ag composite system.The composite samples were prepared by mixing various amounts (2.5 - 50 wt%) AgNO3 in the YBa2Cu3O7−x nitrate precursor solution. These solutions were then spray dried and the resulting powders were either cold pressed or tape cast. The microstructures of the sintered samples were analyzed using SEM (Philips 515) and an analytical TEM (Philips 430T).The SEM micrographs of the compacts with 2.5 and 50 wt% Ag addition sintered at 915°C (below the melting point of Ag) for 1 h in air are displayed in Figs. 1 and 2, respectively.

Cross sections for d-3H neutron interactions with samarium isotopes

2016 ◽  
Vol 104 (8) ◽  
Author(s):  
Junhua Luo ◽  
Chunlei Wu ◽  
Li Jiang ◽  
Long He
Keyword(s):  
Experimental Data ◽  
Neutron Flux ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Nuclear Model ◽  
Activation Technique ◽  
Incident Neutron ◽  
Reaction Threshold ◽  
Talys 1.6 ◽  
The Cross

Abstract:The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the

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