{"id":17799,"date":"2020-06-21T19:56:11","date_gmt":"2020-06-21T19:56:11","guid":{"rendered":"https:\/\/www.radiation-dosimetry.org\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/"},"modified":"2020-07-22T05:34:41","modified_gmt":"2020-07-22T05:34:41","slug":"o-que-e-o-geiger-counter-vs-ionization-chamber-definicao","status":"publish","type":"post","link":"https:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/","title":{"rendered":"O que \u00e9 o Geiger Counter vs Ionization Chamber &#8211; Defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-u-clearfix su-u-trim\">Em geral, o contador Geiger e tamb\u00e9m a c\u00e2mara de ioniza\u00e7\u00e3o s\u00e3o tipos de detectores de ioniza\u00e7\u00e3o gasosa. As c\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no modo atual ou de pulso. Por outro lado, os contadores Geiger s\u00e3o quase sempre usados \u200b\u200bno modo de pulso. Dosimetria de Radia\u00e7\u00e3o<\/div>\n<\/div>\n<div><\/div>\n<div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<p><span>Em geral, o contador Geiger e tamb\u00e9m a c\u00e2mara de ioniza\u00e7\u00e3o s\u00e3o tipos de\u00a0\u00a0<\/span><strong><span>detectores de ioniza\u00e7\u00e3o gasosa.\u00a0<\/span><\/strong><span>Estes podem ser classificados de acordo com a voltagem aplicada ao detector:<\/span><\/p>\n<ul>\n<li><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/ionization-chamber-ion-chamber\/\"><span>c\u00e2maras de ioniza\u00e7\u00e3o<\/span><\/a><span>\u00a0,<\/span><\/li>\n<li><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/proportional-counter-proportional-detector\/\"><span>contadores proporcionais<\/span><\/a><span>\u00a0,<\/span><\/li>\n<li><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/geiger-counter-geiger-mueller-detector\/\"><span>Contadores Geiger-M\u00fcller<\/span><\/a><span>\u00a0.<\/span><\/li>\n<\/ul>\n<p><span>Como em outros detectores, as c\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no modo atual ou de pulso.\u00a0Por outro lado, contadores proporcionais ou contadores Geiger s\u00e3o quase sempre usados \u200b\u200bno modo de pulso.\u00a0Detectores de radia\u00e7\u00e3o ionizante podem ser usados \u200b\u200btanto para\u00a0medi\u00e7\u00f5es de\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/radioactive-decay\/activity-specific-activity\/\"><span>atividade<\/span><\/a><span>\u00a0quanto para\u00a0medi\u00e7\u00f5es de\u00a0<\/span><a href=\"https:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-dose-absorvida-formula-equacao-definicao\/\"><span>dose<\/span><\/a><span>\u00a0.\u00a0Com o conhecimento sobre a energia necess\u00e1ria para formar um par de \u00edons &#8211; a dose pode ser obtida.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-first\">\n<div class=\"inside-grid-column\">\n<h2><span>Contador Geiger<\/span><\/h2>\n<p><span>O\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/geiger-counter-geiger-mueller-detector\/\"><strong><span>contador Geiger<\/span><\/strong><\/a><span>\u00a0, tamb\u00e9m conhecido como\u00a0<\/span><strong><span>contador Geiger-Mueller<\/span><\/strong><span>\u00a0, \u00e9 um dispositivo el\u00e9trico que detecta v\u00e1rios\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/radiation\/forms-ionizing-radiation\/\"><span>tipos de radia\u00e7\u00e3o ionizante<\/span><\/a><span>\u00a0.\u00a0Este dispositivo recebeu o nome dos dois f\u00edsicos que inventaram o contador em 1928. Mueller era aluno de Hans Geiger. \u00a0<\/span><strong><span>O contador Geiger<\/span><\/strong><span>\u00a0\u00e9 amplamente utilizado em aplica\u00e7\u00f5es como dosimetria de radia\u00e7\u00e3o,\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-protection\/\"><span>prote\u00e7\u00e3o radiol\u00f3gica<\/span><\/a><span>\u00a0, f\u00edsica experimental e ind\u00fastria nuclear.\u00a0Um contador Geiger consiste em um\u00a0<\/span><strong><span>tubo Geiger-M\u00fcller<\/span><\/strong><span>\u00a0(o elemento sensor que detecta a radia\u00e7\u00e3o) e a eletr\u00f4nica de processamento, que exibe o resultado.<\/span><\/p>\n<p><strong><span>O contador Geiger<\/span><\/strong><span>\u00a0pode detectar radia\u00e7\u00e3o ionizante, como\u00a0<a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/beta-particle\/\">part\u00edculas\u00a0<\/a><\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/alpha-particle\/\"><span>alfa<\/span><\/a><span>\u00a0\u00a0e\u00a0\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/beta-particle\/\"><span>beta<\/span><\/a><span>\u00a0,\u00a0\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/neutron\/\"><span>n\u00eautrons<\/span><\/a><span>\u00a0e\u00a0\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/photon\/gamma-ray\/\"><span>raios gama,<\/span><\/a><span>\u00a0\u00a0usando o efeito de ioniza\u00e7\u00e3o produzido em um tubo Geiger-M\u00fcller, que d\u00e1 nome ao instrumento.\u00a0A tens\u00e3o do detector \u00e9 ajustada para que as condi\u00e7\u00f5es correspondam \u00e0 regi\u00e3o de\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/operating-regions-of-ionizing-detectors-detector-voltage\/geiger-mueller-region-ionization-detector\/\"><strong><span>Geiger-Mueller<\/span><\/strong><\/a><span>\u00a0.<\/span><\/p>\n<h3><span>Vantagens do contador Geiger-Mueller<\/span><\/h3>\n<ul>\n<li><strong><span>Amplifica\u00e7\u00e3o alta<\/span><\/strong><span>\u00a0.\u00a0Um sinal forte (o\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/proportional-counter-proportional-detector\/gas-amplification-factor-gas-amplification-curve\/\"><strong><span>fator de amplifica\u00e7\u00e3o<\/span><\/strong><\/a><span>\u00a0pode atingir cerca de\u00a0<\/span><strong><span>10\u00a0<\/span><sup><span>10<\/span><\/sup><\/strong><span>\u00a0) \u00e9 produzido por essas avalanches com forma e altura, independentemente da ioniza\u00e7\u00e3o prim\u00e1ria e da energia do f\u00f3ton detectado.\u00a0O pulso de tens\u00e3o neste caso seria um grande e facilmente detect\u00e1vel \u00b1 1.6 V. A vantagem t\u00e9cnica de um contador Geiger \u00e9 sua\u00a0<\/span><strong><span>simplicidade de constru\u00e7\u00e3o<\/span><\/strong><span>\u00a0e sua insensibilidade a pequenas flutua\u00e7\u00f5es de tens\u00e3o.\u00a0Como o processo de amplifica\u00e7\u00e3o de carga melhora muito a rela\u00e7\u00e3o sinal \/ ru\u00eddo do detector, a amplifica\u00e7\u00e3o eletr\u00f4nica subsequente geralmente n\u00e3o \u00e9 necess\u00e1ria.<\/span><\/li>\n<li><strong><span>Simplicidade<\/span><\/strong><span>\u00a0.\u00a0Os contadores GM s\u00e3o usados \u200b\u200bprincipalmente para\u00a0<\/span><strong><span>instrumenta\u00e7\u00e3o port\u00e1til<\/span><\/strong><span>\u00a0devido \u00e0 sua sensibilidade, circuito de contagem simples e capacidade de detectar radia\u00e7\u00e3o de baixo n\u00edvel.\u00a0Os detectores GM s\u00e3o geralmente mais sens\u00edveis a radia\u00e7\u00f5es de baixa energia e baixa intensidade do que os detectores proporcionais ou de c\u00e2mara de \u00edons.<\/span><\/li>\n<li><strong><span>Eletr\u00f4nica mais simples<\/span><\/strong><span>\u00a0.\u00a0Os detectores GM podem ser usados \u200b\u200bcom pacotes eletr\u00f4nicos mais simples.\u00a0A<\/span><br \/>\n<span>sensibilidade de\u00a0entrada\u00a0de um instrumento de pesquisa GM t\u00edpico \u00e9 de 300 a 800 milivolts, enquanto a<\/span><br \/>\n<span>sensibilidade de\u00a0entrada\u00a0de um instrumento de pesquisa proporcional t\u00edpico \u00e9 de 2 milivolt.<\/span><\/li>\n<\/ul>\n<h3><span>Desvantagens do contador Geiger-Mueller<\/span><\/h3>\n<ul>\n<li><strong><span>Sem identifica\u00e7\u00e3o de part\u00edculas, sem resolu\u00e7\u00e3o de energia<\/span><\/strong><span>\u00a0.\u00a0Como a altura do pulso \u00e9 independente do tipo e energia da radia\u00e7\u00e3o, a discrimina\u00e7\u00e3o n\u00e3o \u00e9 poss\u00edvel.\u00a0N\u00e3o h\u00e1 informa\u00e7\u00f5es sobre a natureza da ioniza\u00e7\u00e3o que causou o pulso.\u00a0Os detectores GM n\u00e3o podem discriminar diferentes tipos de radia\u00e7\u00e3o (\u03b1, \u03b2, \u03b3), nem contra v\u00e1rias energias de radia\u00e7\u00e3o.\u00a0Isso ocorre porque o tamanho da avalanche \u00e9 independente da ioniza\u00e7\u00e3o prim\u00e1ria que a criou.<\/span><\/li>\n<li><strong><span>Tempo morto<\/span><\/strong><span>\u00a0.\u00a0Devido \u00e0 grande avalanche induzida por qualquer ioniza\u00e7\u00e3o, um contador Geiger leva muito tempo (cerca de 1 ms) para se recuperar entre pulsos sucessivos.\u00a0Portanto, os contadores Geiger n\u00e3o conseguem medir altas taxas de radia\u00e7\u00e3o devido ao &#8221;\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/detectors-of-ionization-radiation\/dead-time-of-detectors\/\"><strong><span>tempo morto<\/span><\/strong><\/a><span>\u00a0&#8221; do tubo.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-50 lgc-tablet-grid-50 lgc-mobile-grid-100 lgc-equal-heights  lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>C\u00e2mara de ioniza\u00e7\u00e3o<\/span><\/h2>\n<p><span>A\u00a0<strong><a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/ionization-chamber-ion-chamber\/\">c\u00e2mara de ioniza\u00e7\u00e3o<\/a><\/strong>\u00a0, tamb\u00e9m conhecida como\u00a0\u00a0<strong>c\u00e2mara de \u00edons<\/strong>\u00a0, \u00e9 um dispositivo el\u00e9trico que detecta v\u00e1rios tipos de\u00a0\u00a0<a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/radiation\/ionizing-radiation\/\">radia\u00e7\u00e3o ionizante<\/a>\u00a0.\u00a0A tens\u00e3o do detector \u00e9 ajustada para que as condi\u00e7\u00f5es correspondam \u00e0\u00a0\u00a0<a href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/radiation-detection\/gaseous-ionization-detector\/operating-regions-of-ionizing-detectors-detector-voltage\/ionization-region-ionization-detector\/\"><strong>regi\u00e3o de ioniza\u00e7\u00e3o<\/strong><\/a>\u00a0.\u00a0A tens\u00e3o n\u00e3o \u00e9 alta o suficiente para produzir amplifica\u00e7\u00e3o de g\u00e1s (ioniza\u00e7\u00e3o secund\u00e1ria).<\/span><strong>\u00a0<\/strong><\/p>\n<h3><span>Vantagens das c\u00e2maras de ioniza\u00e7\u00e3o<\/span><\/h3>\n<ul>\n<li><strong><span>Modo atual.\u00a0As c\u00e2maras de ioniza\u00e7\u00e3o<\/span><\/strong><span>\u00a0\u00a0s\u00e3o preferidas\u00a0\u00a0<\/span><strong><span>para altas taxas de dose de radia\u00e7\u00e3o,<\/span><\/strong><span>\u00a0\u00a0porque n\u00e3o t\u00eam \u201ctempo morto\u201d, um fen\u00f4meno que afeta a precis\u00e3o do tubo Geiger-Mueller em altas taxas de dose.\u00a0Isso se deve ao fato de n\u00e3o haver amplifica\u00e7\u00e3o de sinal inerente no meio operacional e, portanto, esses tipos de contadores n\u00e3o requerem muito tempo para se recuperar de grandes correntes.\u00a0Al\u00e9m disso, como n\u00e3o h\u00e1 amplifica\u00e7\u00e3o, eles oferecem excelente resolu\u00e7\u00e3o de energia, limitada principalmente pelo ru\u00eddo eletr\u00f4nico.\u00a0C\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no\u00a0\u00a0<\/span><strong><span>modo atual ou de pulso<\/span><\/strong><span>.\u00a0Por outro lado, contadores proporcionais ou contadores Geiger s\u00e3o quase sempre usados \u200b\u200bno modo de pulso.\u00a0Detectores de radia\u00e7\u00e3o ionizante podem ser usados \u200b\u200btanto para medi\u00e7\u00f5es de atividade quanto para medi\u00e7\u00f5es de dose.\u00a0Com o conhecimento sobre a energia necess\u00e1ria para formar um par de \u00edons &#8211; a dose pode ser obtida.\u00a0O\u00a0\u00a0<\/span><strong><span>design da placa plana \u00e9 preferido<\/span><\/strong><span>\u00a0\u00a0porque possui um volume ativo bem definido e garante que os \u00edons n\u00e3o se acumulem nos isoladores e causem uma distor\u00e7\u00e3o do campo el\u00e9trico.<\/span><\/li>\n<li><strong><span>Simplicidade<\/span><\/strong><span>\u00a0.\u00a0A corrente de sa\u00edda \u00e9 independente da tens\u00e3o de opera\u00e7\u00e3o do detector.\u00a0Observe a regi\u00e3o plana da curva na regi\u00e3o da c\u00e2mara de \u00edons.\u00a0Como resultado, fontes de alimenta\u00e7\u00e3o menos reguladas e, portanto, mais baratas e mais port\u00e1teis podem ser usadas com instrumentos de c\u00e2mara de \u00edons e ainda oferecem uma resposta razoavelmente precisa.<\/span><\/li>\n<li><strong><span>Detec\u00e7\u00e3o de n\u00eautrons<\/span><\/strong><span>\u00a0.\u00a0Nos reatores nucleares, as c\u00e2maras de ioniza\u00e7\u00e3o no modo atual s\u00e3o frequentemente usadas para detectar n\u00eautrons e pertencem ao\u00a0<\/span><strong><span>Sistema de Instrumenta\u00e7\u00e3o Nuclear (NIS)<\/span><\/strong><span>\u00a0.\u00a0Por exemplo, se a superf\u00edcie interna da c\u00e2mara de ioniza\u00e7\u00e3o for revestida com uma fina camada de boro, a rea\u00e7\u00e3o (n, alfa) poder\u00e1 ocorrer.\u00a0A maioria das rea\u00e7\u00f5es (n, alfa) dos n\u00eautrons t\u00e9rmicos s\u00e3o rea\u00e7\u00f5es\u00a0\u00a0<\/span><strong><span>10B (n, alfa) 7Li\u00a0<\/span><\/strong><span>\u00a0acompanhadas por\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/photon\/gamma-ray\/\"><span>emiss\u00e3o gama de<\/span><\/a><span>\u00a00,48 MeV\u00a0\u00a0.\u00a0Al\u00e9m disso, o is\u00f3topo boro-10 possui uma alta se\u00e7\u00e3o transversal da rea\u00e7\u00e3o (n, alfa) ao longo de todo\u00a0\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/neutron\/neutron-energy\/\"><span>o espectro de energia de n\u00eautrons<\/span><\/a><span>.\u00a0A part\u00edcula alfa causa ioniza\u00e7\u00e3o dentro da c\u00e2mara e el\u00e9trons ejetados causam ioniza\u00e7\u00f5es secund\u00e1rias adicionais.\u00a0Outro m\u00e9todo para detectar n\u00eautrons usando uma c\u00e2mara de ioniza\u00e7\u00e3o \u00e9 usar o\u00a0<\/span><strong><span>trifluoreto de boro<\/span><\/strong><span>\u00a0gasoso\u00a0\u00a0\u00a0(BF\u00a0<\/span><sub><span>3<\/span><\/sub><span>\u00a0) em vez do ar na c\u00e2mara.\u00a0Os n\u00eautrons recebidos produzem part\u00edculas alfa quando reagem com os \u00e1tomos de boro no g\u00e1s detector.\u00a0Qualquer um dos m\u00e9todos pode ser usado para detectar n\u00eautrons no reator nuclear.<\/span><\/li>\n<\/ul>\n<h3><span>Desvantagens das c\u00e2maras de ioniza\u00e7\u00e3o<\/span><\/h3>\n<ul>\n<li><strong><span>Sem amplifica\u00e7\u00e3o de carga<\/span><\/strong><span>\u00a0.\u00a0Os detectores na regi\u00e3o de ioniza\u00e7\u00e3o operam com uma for\u00e7a de campo el\u00e9trico baixa, selecionada de forma que n\u00e3o ocorra multiplica\u00e7\u00e3o de g\u00e1s.\u00a0A carga coletada (sinal de sa\u00edda) \u00e9 independente da tens\u00e3o aplicada e as part\u00edculas ionizantes m\u00ednimas tendem a ser bem pequenas e geralmente requerem amplificadores especiais de baixo ru\u00eddo para obter desempenho operacional eficiente.\u00a0No ar, a energia m\u00e9dia necess\u00e1ria para produzir um \u00edon \u00e9 de cerca de 34 eV; portanto, uma radia\u00e7\u00e3o de 1 MeV completamente absorvida no detector produz cerca de\u00a0\u00a0<\/span><strong><span>3 x 10\u00a0<\/span><sup><span>4<\/span><\/sup><span>\u00a0\u00a0pares de \u00edons<\/span><\/strong><span>\u00a0.\u00a0No entanto, \u00e9 um sinal pequeno, este sinal pode ser consideravelmente amplificado usando a eletr\u00f4nica padr\u00e3o.\u00a0Uma corrente de 1 micro-amp\u00e8re consiste em cerca de 10\u00a0<\/span><sup><span>12<\/span><\/sup><span>\u00a0\u00a0el\u00e9trons por segundo.<\/span><\/li>\n<li><strong><span>Baixa densidade<\/span><\/strong><span>\u00a0.\u00a0Os raios gama depositam uma quantidade significativamente menor de energia no detector do que outras part\u00edculas.\u00a0A efici\u00eancia da c\u00e2mara pode ser aumentada ainda mais pelo uso de um g\u00e1s de alta press\u00e3o.<\/span><\/li>\n<li><span>Para que as\u00a0\u00a0<a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/beta-particle\/\">part\u00edculas\u00a0<\/a><\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/alpha-particle\/\"><span>alfa<\/span><\/a><span>\u00a0\u00a0e\u00a0\u00a0<\/span><a href=\"https:\/\/www.nuclear-power.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/fundamental-particles\/beta-particle\/\"><span>beta<\/span><\/a><span>\u00a0\u00a0sejam detectadas pelas c\u00e2maras de ioniza\u00e7\u00e3o, elas devem ter uma\u00a0\u00a0<\/span><strong><span>janela fina<\/span><\/strong><span>\u00a0.\u00a0Essa &#8220;janela final&#8221; deve ser fina o suficiente para que as part\u00edculas alfa e beta penetrem.\u00a0No entanto, uma janela de quase qualquer espessura impedir\u00e1 que uma part\u00edcula alfa entre na c\u00e2mara.\u00a0A janela \u00e9 geralmente feita de mica com uma densidade de cerca de 1,5 &#8211; 2,0 mg \/ cm\u00a0<\/span><sup><span>2<\/span><\/sup><span>\u00a0.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<figure id=\"attachment_26092\" class=\"wp-caption aligncenter\" aria-describedby=\"caption-attachment-26092\"><a href=\"https:\/\/www.radiation-dosimetry.org\/wp-content\/uploads\/2019\/12\/Gaseous-Ionization-Detectors-Regions-min.png\"><img loading=\"lazy\" class=\"size-large wp-image-26092 lazy-loaded\" src=\"https:\/\/www.radiation-dosimetry.org\/wp-content\/uploads\/2019\/12\/Gaseous-Ionization-Detectors-Regions-min-1024x603.png\" alt=\"Detectores de ioniza\u00e7\u00e3o gasosa - Regi\u00f5es\" width=\"1024\" height=\"603\" data-lazy-type=\"image\" data-src=\"https:\/\/www.radiation-dosimetry.org\/wp-content\/uploads\/2019\/12\/Gaseous-Ionization-Detectors-Regions-min-1024x603.png\" \/><\/a><figcaption id=\"caption-attachment-26092\" class=\"wp-caption-text\"><span>Este diagrama mostra o n\u00famero de pares de \u00edons gerados no detector a g\u00e1s, que varia de acordo com a tens\u00e3o aplicada \u00e0 radia\u00e7\u00e3o incidente constante.\u00a0As tens\u00f5es podem variar amplamente, dependendo da geometria do detector e do tipo e press\u00e3o do g\u00e1s.\u00a0Esta figura indica esquematicamente as diferentes regi\u00f5es de tens\u00e3o dos raios alfa, beta e gama.\u00a0Existem seis principais regi\u00f5es operacionais pr\u00e1ticas, nas quais tr\u00eas (regi\u00e3o de ioniza\u00e7\u00e3o, proporcional e Geiger-Mueller) s\u00e3o \u00fateis para detectar radia\u00e7\u00e3o ionizante.\u00a0As part\u00edculas alfa s\u00e3o mais ionizantes que as part\u00edculas beta e os raios gama; portanto, mais corrente \u00e9 produzida na regi\u00e3o da c\u00e2mara de \u00edons por alfa do que beta e gama, mas as part\u00edculas n\u00e3o podem ser diferenciadas.\u00a0Mais corrente \u00e9 produzida na regi\u00e3o de contagem proporcional por part\u00edculas alfa que beta,\u00a0mas, pela natureza da contagem proporcional, \u00e9 poss\u00edvel diferenciar pulsos alfa, beta e gama.\u00a0Na regi\u00e3o de Geiger, n\u00e3o h\u00e1 diferencia\u00e7\u00e3o de alfa e beta, pois qualquer evento de ioniza\u00e7\u00e3o isolado no g\u00e1s resulta na mesma sa\u00edda de corrente.<\/span><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-arrow\" data-anchor=\"References\">\n<div class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<p>&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p>Este artigo \u00e9 baseado na tradu\u00e7\u00e3o autom\u00e1tica do artigo original em ingl\u00eas. Para mais informa\u00e7\u00f5es, consulte o artigo em ingl\u00eas. Voc\u00ea pode nos ajudar. Se voc\u00ea deseja corrigir a tradu\u00e7\u00e3o, envie-a para: translations@nuclear-power.com ou preencha o formul\u00e1rio de tradu\u00e7\u00e3o on-line. Agradecemos sua ajuda, atualizaremos a tradu\u00e7\u00e3o o mais r\u00e1pido poss\u00edvel. Obrigado.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Em geral, o contador Geiger e tamb\u00e9m a c\u00e2mara de ioniza\u00e7\u00e3o s\u00e3o tipos de detectores de ioniza\u00e7\u00e3o gasosa. As c\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no modo atual ou de pulso. Por outro lado, os contadores Geiger s\u00e3o quase sempre usados \u200b\u200bno modo de pulso. Dosimetria de Radia\u00e7\u00e3o Em geral, o contador Geiger e tamb\u00e9m &#8230; <a title=\"O que \u00e9 o Geiger Counter vs Ionization Chamber &#8211; Defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/\" aria-label=\"More on O que \u00e9 o Geiger Counter vs Ionization Chamber &#8211; Defini\u00e7\u00e3o\">Ler mais<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[51],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v15.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>O que \u00e9 o Geiger Counter vs Ionization Chamber - Defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"Em geral, o contador Geiger e tamb\u00e9m a c\u00e2mara de ioniza\u00e7\u00e3o s\u00e3o tipos de detectores de ioniza\u00e7\u00e3o gasosa. As c\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no modo atual ou de pulso. Por outro lado, os contadores Geiger s\u00e3o quase sempre usados no modo de pulso. Dosimetria de Radia\u00e7\u00e3o\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/\" \/>\n<meta property=\"og:locale\" content=\"pt_BR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"O que \u00e9 o Geiger Counter vs Ionization Chamber - Defini\u00e7\u00e3o\" \/>\n<meta property=\"og:description\" content=\"Em geral, o contador Geiger e tamb\u00e9m a c\u00e2mara de ioniza\u00e7\u00e3o s\u00e3o tipos de detectores de ioniza\u00e7\u00e3o gasosa. As c\u00e2maras de ioniza\u00e7\u00e3o podem ser operadas no modo atual ou de pulso. Por outro lado, os contadores Geiger s\u00e3o quase sempre usados no modo de pulso. Dosimetria de Radia\u00e7\u00e3o\" \/>\n<meta property=\"og:url\" content=\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/\" \/>\n<meta property=\"og:site_name\" content=\"Radiation Dosimetry\" \/>\n<meta property=\"article:published_time\" content=\"2020-06-21T19:56:11+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2020-07-22T05:34:41+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.radiation-dosimetry.org\/wp-content\/uploads\/2019\/12\/Gaseous-Ionization-Detectors-Regions-min-1024x603.png\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\">\n\t<meta name=\"twitter:data1\" content=\"Nick Connor\">\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\">\n\t<meta name=\"twitter:data2\" content=\"7 minutos\">\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.radiation-dosimetry.org\/#website\",\"url\":\"https:\/\/www.radiation-dosimetry.org\/\",\"name\":\"Radiation Dosimetry\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":\"https:\/\/www.radiation-dosimetry.org\/?s={search_term_string}\",\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"pt-BR\"},{\"@type\":\"ImageObject\",\"@id\":\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/#primaryimage\",\"inLanguage\":\"pt-BR\",\"url\":\"\",\"caption\":\"Dieses Diagramm zeigt die Anzahl der im gasgef\\u00fcllten Detektor erzeugten Ionenpaare, die je nach angelegter Spannung f\\u00fcr konstant einfallende Strahlung variiert. Die Spannungen k\\u00f6nnen in Abh\\u00e4ngigkeit von der Detektorgeometrie und der Gasart und dem Druck stark variieren. Diese Abbildung zeigt schematisch die verschiedenen Spannungsbereiche f\\u00fcr Alpha-, Beta- und Gammastrahlen. Es gibt sechs praktische Hauptbetriebsbereiche, in denen drei (Ionisations-, Proportional- und Geiger-M\\u00fcller-Bereich) n\\u00fctzlich sind, um ionisierende Strahlung zu erfassen. Alphateilchen sind ionisierender als Betateilchen und als Gammastrahlen, so dass durch Alpha mehr Strom in der Ionenkammerregion erzeugt wird als durch Beta und Gamma, aber die Teilchen k\\u00f6nnen nicht unterschieden werden. Im Proportionalz\\u00e4hlbereich wird durch Alphateilchen mehr Strom erzeugt als durch Beta, aber durch die Art des Proportionalz\\u00e4hlens ist es m\\u00f6glich, Alpha-, Beta- und Gamma-Impulse zu unterscheiden. In der Geigerregion gibt es keine Unterscheidung zwischen Alpha und Beta, da ein einzelnes Ionisationsereignis im Gas zur gleichen Stromabgabe f\\u00fchrt.\"},{\"@type\":\"WebPage\",\"@id\":\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/#webpage\",\"url\":\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/\",\"name\":\"O que \\u00e9 o Geiger Counter vs Ionization Chamber - Defini\\u00e7\\u00e3o\",\"isPartOf\":{\"@id\":\"https:\/\/www.radiation-dosimetry.org\/#website\"},\"primaryImageOfPage\":{\"@id\":\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/#primaryimage\"},\"datePublished\":\"2020-06-21T19:56:11+00:00\",\"dateModified\":\"2020-07-22T05:34:41+00:00\",\"author\":{\"@id\":\"https:\/\/www.radiation-dosimetry.org\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\"},\"description\":\"Em geral, o contador Geiger e tamb\\u00e9m a c\\u00e2mara de ioniza\\u00e7\\u00e3o s\\u00e3o tipos de detectores de ioniza\\u00e7\\u00e3o gasosa. As c\\u00e2maras de ioniza\\u00e7\\u00e3o podem ser operadas no modo atual ou de pulso. Por outro lado, os contadores Geiger s\\u00e3o quase sempre usados no modo de pulso. Dosimetria de Radia\\u00e7\\u00e3o\",\"inLanguage\":\"pt-BR\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"http:\/\/www.radiation-dosimetry.org\/pt-br\/o-que-e-o-geiger-counter-vs-ionization-chamber-definicao\/\"]}]},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.radiation-dosimetry.org\/#\/schema\/person\/e8c544db9afedaec8574d6464f9398bb\",\"name\":\"Nick Connor\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","_links":{"self":[{"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/posts\/17799"}],"collection":[{"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/comments?post=17799"}],"version-history":[{"count":0,"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/posts\/17799\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/media?parent=17799"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/categories?post=17799"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.radiation-dosimetry.org\/pt-br\/wp-json\/wp\/v2\/tags?post=17799"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}