<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2008000700015</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Neutron room return effect]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vega-Carrillo]]></surname>
<given-names><![CDATA[H.R]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gallego]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<xref ref-type="aff" rid="A03"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Manzanares-Acuña]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Lorente]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<xref ref-type="aff" rid="A03"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Barquero]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
<xref ref-type="aff" rid="A04"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Martin-Martin]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<xref ref-type="aff" rid="A05"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gutierrez-Villanueva]]></surname>
<given-names><![CDATA[J.L]]></given-names>
</name>
<xref ref-type="aff" rid="A05"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Unidades Académicas de Estudios Nucleares  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
</aff>
<aff id="A02">
<institution><![CDATA[,Universidad Autónoma de Zacatecas Ingeniería Eléctrica ]]></institution>
<addr-line><![CDATA[Zacatecas Zac]]></addr-line>
<country>México</country>
</aff>
<aff id="A03">
<institution><![CDATA[,Universidad Politécnica de Madrid Departamento de Ingeniería Nuclear ]]></institution>
<addr-line><![CDATA[Madrid ]]></addr-line>
<country>Spain</country>
</aff>
<aff id="A04">
<institution><![CDATA[,Hospital del Rio Hortega  ]]></institution>
<addr-line><![CDATA[Valladolid ]]></addr-line>
<country>Spain</country>
</aff>
<aff id="A05">
<institution><![CDATA[,Universidad de Valladolid Departamento de Fisica Teórica, Atómica y Optica Laboratorio LIBRA]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Spain</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>02</month>
<year>2008</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>02</month>
<year>2008</year>
</pub-date>
<volume>54</volume>
<fpage>63</fpage>
<lpage>66</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2008000700015&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2008000700015&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2008000700015&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[The coefficient that relates the neutron source strength and room surface area with the thermal neutron fluence rates has been calculated for neutrons whose energy goes from 1 eV to 20 MeV. This coefficient was calculated using Monte Carlo methods for several room's radii where a point-like source was located at the center of the room while detectors were located along the room's radius. Calculations were performed with the room with air and in vacuum.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[El coeficiente que relaciona la intensidad de una fuente de neutrones y el area de la superficie interna de un recinto con la tasa de fluencia de los neutrones térmicos ha sido calculado para neutrones monoenergéticos cuyas energías varían de 1 eV a 20 MeV. El coeficiente ha sido calculado mediante metodos Monte Carlos para varios recintos esféricos con muros de concreto de 1 metro de espesor. En los cálculos la fuente puntual se localizó en el centro de cada recinto y los detectores se ubicaron, a diferentes distancias, a lo largo del radio. Los cálculos se realizaron considerando que los recintos esfericos estaban llenos de aire y en el vacío.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Room-return]]></kwd>
<kwd lng="en"><![CDATA[neutrons]]></kwd>
<kwd lng="en"><![CDATA[Monte Carlo]]></kwd>
<kwd lng="es"><![CDATA[Room-return]]></kwd>
<kwd lng="es"><![CDATA[neutrones]]></kwd>
<kwd lng="es"><![CDATA[Monte Carlo]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="center"><font face="verdana" size="4"><b>Neutron room return effect</b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>H.R. Vega&#150;Carrillo* <sup>a , b</sup> , E. Gallego<sup>c</sup>, E. Manzanares&#150;Acu&ntilde;a&ordf;, A. Lorente<sup>c</sup>, R. Barquero<sup>d</sup>, A. Martin&#150;Martin<sup>e</sup>, and J.L. Gutierrez&#150;Villanueva<sup>e</sup></b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><i>&ordf; Unidades Acad&eacute;micas de Estudios Nucleares * Correspondig author e&#150;mail: <a href="MAILTO:fermineutron@yahoo.com">fermineutron@yahoo.com</a> . </i></font></p>     <p align="justify"><font face="verdana" size="2"><i><sup>b</sup> Ingenier&iacute;a El&eacute;ctrica, Universidad Aut&oacute;noma de Zacatecas, apartado postal # 336, 98000 Zacatecas, Zac. M&eacute;xico.</i></font></p>     <p align="justify"><font face="verdana" size="2"><i><sup>c</sup> Departamento de Ingenier&iacute;a Nuclear, Universidad Polit&eacute;cnica de Madrid, Jos&eacute; Gutierrez Abascal 2 28006 Madrid, Spain. </i></font></p>     <p align="justify"><font face="verdana" size="2"><i><sup>d </sup>Hospital del Rio Hortega, Valladolid, Spain.</i></font></p>     <p align="justify"><font face="verdana" size="2"><i><sup>e</sup> Departamento de Fisica Te&oacute;rica, At&oacute;mica y Optica, Laboratorio LIBRA, Universidad de Valladolid, Spain</i></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">Recibido el 14 de mayo de 2007    <br> Aceptado el 26 de octubre de 2007</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">The coefficient that relates the neutron source strength and room surface area with the thermal neutron fluence rates has been calculated for neutrons whose energy goes from 1 eV to 20 MeV. This coefficient was calculated using Monte Carlo methods for several room's radii where a point&#150;like source was located at the center of the room while detectors were located along the room's radius. Calculations were performed with the room with air and in vacuum. </font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords:</b> Room&#150;return; neutrons; Monte Carlo.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">El coeficiente que relaciona la intensidad de una fuente de neutrones y el area de la superficie interna de un recinto con la tasa de fluencia de los neutrones t&eacute;rmicos ha sido calculado para neutrones monoenerg&eacute;ticos cuyas energ&iacute;as var&iacute;an de 1 eV a 20 MeV. El coeficiente ha sido calculado mediante metodos Monte Carlos para varios recintos esf&eacute;ricos con muros de concreto de 1 metro de espesor. En los c&aacute;lculos la fuente puntual se localiz&oacute; en el centro de cada recinto y los detectores se ubicaron, a diferentes distancias, a lo largo del radio. Los c&aacute;lculos se realizaron considerando que los recintos esfericos estaban llenos de aire y en el vac&iacute;o.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores: </b>Room&#150;return; neutrones; Monte Carlo. </font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">PACS:  14.20.Dh;28.20.Gd;24.10.Lx</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmf/v54s1/v54s1a15.pdf">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Acknowledgments</b></font></p>     <p align="justify"><font face="verdana" size="2">This work is part of SYNAPSIS research project partially supported by CONACyT (M&eacute;xico) under contract SEP&#150;2004&#150;C01&#150;46893.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. R. <i>McCall, Med. </i>Phys <b>26</b> (1999) 206.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348426&pid=S0035-001X200800070001500001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">2. T. Ishikawa, H. Sugita, and T. Nakamura, <i>Health Physics </i><b>60</b> (1991) 209.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348427&pid=S0035-001X200800070001500002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">3. H.W. Patterson and R.H. Thomas, <i>Accelerator Health Physics, </i>Academic Press (New York, 1973).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348428&pid=S0035-001X200800070001500003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">4. P.H. McGinley and J.C. Landry, <i>Physics in Medicine and Biology </i><b>34</b> (1989) 777.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348429&pid=S0035-001X200800070001500004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">5. N.E. Hertel <i>et al., Radiation Protection Dosimetry </i><b>108 </b>(2004) 255.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348430&pid=S0035-001X200800070001500005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">6. E. Gallego, A. Lorente, and H.R. Vega&#150;Carrillo, <i>Radiation Protection Dosimetry </i><b>110 </b>(2004) 73.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348431&pid=S0035-001X200800070001500006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">7. A.M. Williams, P.A. Beeley, and N.M. Spyrou, <i>Radiation Protection Dosimetry </i><b>110 </b>(2004) 497.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348432&pid=S0035-001X200800070001500007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">8. Uwamino <i>et al., Radiation Protection Dosimetry </i><b>115 </b>(2005) 279.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348433&pid=S0035-001X200800070001500008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">9. J.F. Briestmeister, editor, <i>MCNP<sup>TM</sup>&#150;A general Monte Carlo N&#150;particle transport code, </i>Los Alamos National Laboratory Report <b>LA&#150;13709&#150;M </b>(2000).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348434&pid=S0035-001X200800070001500009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">10. C.M. Eisenhauer,  R.B. Schwartz,  and T. Johnson, <i>Health Physics </i><b>42</b> (1982) 489.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348435&pid=S0035-001X200800070001500010&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">11. C.M. Eisenhauer, <i>Radiation Protection Dosimetry </i><b>28</b> (1989) 253.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8348436&pid=S0035-001X200800070001500011&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McCall]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
</person-group>
<source><![CDATA[Med. Phys]]></source>
<year>1999</year>
<numero>26</numero>
<issue>26</issue>
<page-range>206</page-range></nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ishikawa]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Sugita]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
<name>
<surname><![CDATA[Nakamura]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
</person-group>
<source><![CDATA[Health Physics]]></source>
<year>1991</year>
<numero>60</numero>
<issue>60</issue>
<page-range>209</page-range></nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Patterson]]></surname>
<given-names><![CDATA[H.W]]></given-names>
</name>
<name>
<surname><![CDATA[Thomas]]></surname>
<given-names><![CDATA[R.H]]></given-names>
</name>
</person-group>
<source><![CDATA[Accelerator Health Physics]]></source>
<year>1973</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Academic Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McGinley]]></surname>
<given-names><![CDATA[P.H]]></given-names>
</name>
<name>
<surname><![CDATA[Landry]]></surname>
<given-names><![CDATA[J.C]]></given-names>
</name>
</person-group>
<source><![CDATA[Physics in Medicine and Biology]]></source>
<year>1989</year>
<numero>34</numero>
<issue>34</issue>
<page-range>777</page-range></nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hertel]]></surname>
<given-names><![CDATA[N.E]]></given-names>
</name>
</person-group>
<source><![CDATA[Radiation Protection Dosimetry]]></source>
<year>2004</year>
<numero>108</numero>
<issue>108</issue>
<page-range>255</page-range></nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gallego]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Lorente]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Vega-Carrillo]]></surname>
<given-names><![CDATA[H.R]]></given-names>
</name>
</person-group>
<source><![CDATA[Radiation Protection Dosimetry]]></source>
<year>2004</year>
<numero>110</numero>
<issue>110</issue>
<page-range>73</page-range></nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Williams]]></surname>
<given-names><![CDATA[A.M]]></given-names>
</name>
<name>
<surname><![CDATA[Beeley]]></surname>
<given-names><![CDATA[P.A]]></given-names>
</name>
<name>
<surname><![CDATA[Spyrou]]></surname>
<given-names><![CDATA[N.M]]></given-names>
</name>
</person-group>
<source><![CDATA[Radiation Protection Dosimetry]]></source>
<year>2004</year>
<numero>110</numero>
<issue>110</issue>
<page-range>497</page-range></nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Uwamino]]></surname>
</name>
</person-group>
<source><![CDATA[Radiation Protection Dosimetry]]></source>
<year>2005</year>
<numero>115</numero>
<issue>115</issue>
<page-range>279</page-range></nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Briestmeister]]></surname>
<given-names><![CDATA[J.F]]></given-names>
</name>
</person-group>
<source><![CDATA[MCNP TM-A general Monte Carlo N-particle transport code]]></source>
<year>2000</year>
<publisher-name><![CDATA[Los Alamos National Laboratory]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B10">
<label>10</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Eisenhauer]]></surname>
<given-names><![CDATA[C.M]]></given-names>
</name>
<name>
<surname><![CDATA[Schwartz]]></surname>
<given-names><![CDATA[R.B]]></given-names>
</name>
<name>
<surname><![CDATA[Johnson]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
</person-group>
<source><![CDATA[Health Physics]]></source>
<year>1982</year>
<numero>42</numero>
<issue>42</issue>
<page-range>489</page-range></nlm-citation>
</ref>
<ref id="B11">
<label>11</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Eisenhauer]]></surname>
<given-names><![CDATA[C.M]]></given-names>
</name>
</person-group>
<source><![CDATA[Radiation Protection Dosimetry]]></source>
<year>1989</year>
<numero>28</numero>
<issue>28</issue>
<page-range>253</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
