Introduction

The main objective of this website is to make available scientific articles written by  Eduardo J. C. Martinho, José F. Salgado and Isabel Maria F. Gonçalves, from the Instituto Tecnológico e Nuclear, Sacavém, Portugal.

The research, published between 2001 and 2004, was about a relevant phenomenon in reactor and neutron physics called neutron self-shielding, which comprises resonance neutron self-shielding (Gres) and thermal neutron self-shielding (Gth). The practical importance of our work resides in the final conclusion that the phenomenon can be quantified by a universal law of Gres and Gth for foils, wires, spheres and cylinders.

BLOG Gráfico 03 Neutron flux profile resulting from the self-shielding effect in a sample

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The innovation of our final results has been summarized by a Canadian team* as follows:

«(…) Historically, the calculation of Gth and Gep [or Gres] was extremely difficult, and it was recommen­ded to dilute the samples to avoid self-shielding. Fortunately, reactor physicists recently showed that the amount of epithermal as well as thermal self-shielding could be expressed by the same analytical function, a sigmoid, for all nuclides [2–4]**. (…)»

* C. Chilian, R. Chambon, G. Kennedy: Neutron self-shielding with k0NAA irradiations. Nuclear Instruments and Methods in Physics Research A 622 (2) (2010) 429-432].

** CITED REFERENCES:

[2] E. Martinho, I.F. Gonçalves, J. Salgado, Universal curve of epithermal neutron resonance self-shielding factors in foils, wires and spheres. Applied Radiation and Isotopes 58(3) (2003) 371-375;

[3] I.F. Gonçalves, E. Martinho, J. Salgado, Extension to cylindrical samples of the universal curve of resonance neutron self-shielding factors. Nuclear Instruments and Methods in Physics Research B 213 (2004) 186-188;

[4] E. Martinho, J. Salgado, I.F. Gonçalves, Universal curve of thermal neutron self-shielding factors in foils, wires, spheres and cylinders. Journal of Radioanalytical and Nuclear Chemistry 261 (3) (2004) 637-643.

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Scientists from several countries [Algeria, Argentina, Australia, Austria, Bangladesh, Belgium, Brazil, Bulgaria, Canada, Chile, China, Cuba, Denmark, Egypt, France, Germany, Greece, Hungary, India, Indonesia, Iran, Italy, Japan, Kazakhstan, Malaysia, Mexico, Pakistan, Peru, Portugal, Romania, Slovenia, South Korea, Switzerland, Taiwan, The Netherlands, Turkey, United Kingdom, United States of America, Uzbekistan and Vietnam] and international institutions [Joint Research Centre/EU (Geel, Petten, Ispra) and International Atomic Energy Agency (Vienna)] are using our results in works related to various­ domains, namely reactor neutron metrology, determination of nuclear parameters (thermal neutron cross-sections and resonance integrals), neutron activation analysis, production of radioisotopes for medical applications.

CITATIONS: http://tempoderecordar-edmartinho.blogspot.pt/2015/11/neutron-self-shielding-citations.html

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CONTENTS:

https://edmartinho.files.wordpress.com/2010/03/01-2001-calculation-of-resonance-neutron-self-shielding-factors3.pdf

https://edmartinho.files.wordpress.com/2010/03/02-2001-calculation-of-resonance-neutron-self-shielding-factors-in-wires1.pdf

https://edmartinho.files.wordpress.com/2010/03/03-2002-calculation-of-resonance-neutron-self-shielding-factors-in-foils1.pdf

https://edmartinho.files.wordpress.com/2010/03/04-2003universal-curve-of-resonance-neutron-self-shielding-factors-foils-wires-spheres.pdf

https://edmartinho.files.wordpress.com/2010/03/05-2004-extension-of-universal-curve-of-resonance-neutron-self-shielding-factors-to-cylindrical-samples.pdf

https://edmartinho.files.wordpress.com/2010/03/06-2004-calculation-of-neutron-self-shielding-factors-of-a-group-of-resonances.pdf

https://edmartinho.files.wordpress.com/2010/03/07-2004-resonance-neutron-self-shielding-factors-in-foils-for-collimated-beams.pdf

https://edmartinho.files.wordpress.com/2010/03/08-2003-thermal-neutron-self-shielding-factors-in-foils-a-universal-curve.pdf

https://edmartinho.files.wordpress.com/2010/03/09-2004-universal-curve-of-thermal-neutron-self-shielding-factors-foils-wires-spheres-cylinders.pdf

https://edmartinho.files.wordpress.com/2010/04/10-2004-development-of-a-unique-curve-for-gth-in-spherical-scattering-materials.pdf

https://edmartinho.wordpress.com/2010/04/09/comparison-of-the-universal-curve-uc-with-published-results-3/

https://edmartinho.files.wordpress.com/2010/04/2004-gf-uma-inesperada-curva-universal.pdf (in portuguese)

https://edmartinho.wordpress.com/2010/08/29/universal-curves-of-gres-and-gth/

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edmartinho@gmail.com

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