{"id":204,"date":"2018-04-19T12:21:08","date_gmt":"2018-04-19T10:21:08","guid":{"rendered":"http:\/\/134.158.130.108\/wordpress\/?page_id=204"},"modified":"2019-06-09T22:14:15","modified_gmt":"2019-06-09T20:14:15","slug":"more","status":"publish","type":"page","link":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/more\/","title":{"rendered":"Read more about charged particles for medicine"},"content":{"rendered":"<h1>\u00a0Les particules charg\u00e9es pour la m\u00e9decine<\/h1>\n<p>(english translation ongoing)<\/p>\n<h2 class=\"date\">Le cyclotron<\/h2>\n<div class=\"crayon article-texte-1979 texte\">\n<p><br class=\"autobr\" \/>Mis au point par Ernest Lawrence dans les ann\u00e9es 30, le cyclotron permet l\u2019acc\u00e9l\u00e9ration de particules charg\u00e9es. Les particules sont soumises \u00e0 la force de Lorentz\u00a0:<\/p>\n<p><br class=\"autobr\" \/><strong>F<\/strong> = q(<strong>E<\/strong> + <strong>v<\/strong> x <strong>B<\/strong>)<\/p>\n<p><br class=\"autobr\" \/>Cette force contient deux composantes\u00a0: le champ \u00e9lectrique <strong>E<\/strong> qui acc\u00e9l\u00e8re les particules et le champ mag\u00e9ntique <strong>B<\/strong> qui modifie leurs trajectoires.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-236 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im1-More-BL-2.png\" alt=\"\" width=\"353\" height=\"314\" srcset=\"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im1-More-BL-2.png 353w, https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im1-More-BL-2-300x267.png 300w\" sizes=\"auto, (max-width: 353px) 100vw, 353px\" \/><\/p>\n<p><br class=\"autobr\" \/>Dans un cyclotron le faisceau est courb\u00e9 par un champ magn\u00e9tique dans des \u00e9lectrodes appel\u00e9es &#8220;Dees&#8221; et acc\u00e9l\u00e9r\u00e9 dans le gap entre les \u00e9letrodes par un champ \u00e9lectrique alternatif. La trajectoire r\u00e9sultante est une spirale. Apr\u00e8s un certains nombres de tours, les particules ont atteint l\u2019\u00e9nergie maximum, elles sont alors extraites de la machine.<\/p>\n<h2 class=\"spip\">Le transport du faisceau<\/h2>\n<p><br class=\"autobr\" \/>Il est effectu\u00e9 par une s\u00e9rie d\u2019aimants r\u00e9alisants diff\u00e9rentes op\u00e9rations\u00a0:<\/p>\n<ul>\n<li>Les aimants dip\u00f4laires courbent la trajectoire du faiseau. Ils sont utilis\u00e9s pour diriger le faisceau.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-238 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im2-More-BL-1.png\" alt=\"\" width=\"124\" height=\"117\" \/><\/p>\n<ul>\n<li>Les aimants quadrup\u00f4laires focalisent le faiseau. Ils ont la particularit\u00e9 de focaliser dans une direction et de d\u00e9focaliser dans l\u2019autre. L\u2019espace entre deux quadrup\u00f4les permet d\u2019obtenir un effet focalisant dans les deux directions.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-239 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im3-More-BL.png\" alt=\"\" width=\"124\" height=\"117\" \/><\/p>\n<ul>\n<li>Les hexap\u00f4les corrigents les defauts de chromaticit\u00e9 (des particules avec des \u00e9nergies diff\u00e9rentes sont focalis\u00e9es \u00e0 des endroits diff\u00e9rents) d\u00fbs \u00e0 la focalisation par les quadrup\u00f4les.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-240 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im4-More-BL.png\" alt=\"\" width=\"124\" height=\"117\" \/><\/p>\n<p>Illustration chromaticit\u00e9\u00a0!<\/p>\n<h2 class=\"spip\">Ajustement en \u00e9nergie<\/h2>\n<p><br class=\"autobr\" \/>Un d\u00e9gradeur constitu\u00e9 d\u2019un disque d\u2019\u00e9paisseur variable en rotation permet d\u2019ajuster l\u2019\u00e9nergie.<\/p>\n<h2 class=\"spip\">Dispersion en \u00e9nergie<\/h2>\n<p><br class=\"autobr\" \/>Un syst\u00e8me de fentes permet de diminuer la dispersion en \u00e9nergie.<\/p>\n<h2 class=\"spip\">Le profileur de faisceau<\/h2>\n<p><br class=\"autobr\" \/>Il fournit une mesure de la position et de la distribution du faiseau. Les profileurs sont pr\u00e9sents \u00e0 plusieurs endroits des lignes.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-241 \" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im5-More-BL.png\" alt=\"\" width=\"284\" height=\"125\" \/><\/p>\n<\/div>\n<p><!--more--><\/p>\n<p>&nbsp;<\/p>\n<h2>Le pic de Bragg<\/h2>\n<h2 class=\"spip\">Double scattering<\/h2>\n<p><br class=\"autobr\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-242 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im6-More-BL.png\" alt=\"\" width=\"413\" height=\"159\" srcset=\"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im6-More-BL.png 413w, https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im6-More-BL-300x115.png 300w\" sizes=\"auto, (max-width: 413px) 100vw, 413px\" \/><\/p>\n<h2 class=\"spip\">Pencil beam scanning<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-243 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im7-More-BL.png\" alt=\"\" width=\"413\" height=\"159\" srcset=\"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im7-More-BL.png 413w, https:\/\/llrwebpepites.in2p3.fr\/wordpress\/wp-content\/uploads\/2018\/04\/Im7-More-BL-300x115.png 300w\" sizes=\"auto, (max-width: 413px) 100vw, 413px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><!--more--><\/p>\n<h2 class=\"spip\">Imagerie<\/h2>\n<ul>\n<li><strong>Scintigraphie <\/strong>\u00a0: C\u2019est une m\u00e9thode d\u2019imagerie qui repose sur la d\u00e9tection de rayonnement \u03b3 \u00e9mis par la d\u00e9croissance radioactive d\u2019un traceur. Le traceur est associ\u00e9 \u00e0 un vecteur choisit en fonction de l\u2019organe cibl\u00e9. La d\u00e9tection s\u2019effectue avec une \u03b3 cam\u00e9ra constitu\u00e9e d\u2019un scintillateur.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-244 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im8-More-BL.png\" alt=\"\" width=\"252\" height=\"170\" \/><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong>TEP<\/strong>\u00a0: La tomographie par \u00e9mission de positrons est un type de scintigraphie dans laquelle le traceur est un \u00e9metteur \u03b2+. Les positrons \u00e9mis s\u2019annihilent avec les \u00e9lectrons du milieu produisant une paire de photons qui partent \u00e0 180\u00b0 l\u2019un de l\u2019autre. Un syst\u00e8me de d\u00e9tection en co\u00efncidence permet la localisation du lieu d\u2019\u00e9mission et donc de reconstituer l\u2019image qui correspond \u00e0 la densit\u00e9 de traceur.<\/li>\n<\/ul>\n<p><br class=\"autobr\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-245 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im9-More-BL.png\" alt=\"\" width=\"252\" height=\"170\" \/><\/p>\n<h2 class=\"spip\">Radioth\u00e9rapie<\/h2>\n<p><br class=\"autobr\" \/>Traitement du cancer par radiations. Les radiations endommagent l\u2019ADN des cellules vis\u00e9es ce qui entra\u00eenent leurs destructions. La radioth\u00e9rapie peut \u00eatre interne (source implant\u00e9e dans le patient), interne vectoris\u00e9e (radionucl\u00e9\u00efde associ\u00e9 \u00e0 une mol\u00e9cule vectrice), externe (protons, \u00e9lectrons, neutrons&#8230;)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-246 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im10-More-BL.png\" alt=\"\" width=\"188\" height=\"226\" \/><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong>Immunotherapie <\/strong>\u00a0: Type de radioth\u00e9rapie vectoris\u00e9e. Administration d\u2019un complexe anticorps-radionucl\u00e9\u00efdes qui cible un antig\u00e8ne pr\u00e9sent sur une tumeur.<br class=\"autobr\" \/><br class=\"autobr\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-247 size-full\" src=\"http:\/\/134.158.130.108\/wordpress\/wp-content\/uploads\/2018\/04\/Im11-More-BL.png\" alt=\"\" width=\"271\" height=\"226\" \/><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0Les particules charg\u00e9es pour la m\u00e9decine (english translation ongoing) Le cyclotron Mis au point par Ernest Lawrence dans les ann\u00e9es 30, le cyclotron permet l\u2019acc\u00e9l\u00e9ration de particules charg\u00e9es. Les particules sont soumises \u00e0 la force de Lorentz\u00a0: F = q(E + v x B) Cette force contient deux composantes\u00a0: le champ \u00e9lectrique E qui acc\u00e9l\u00e8re &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/more\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Read more about charged particles for medicine&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"class_list":["post-204","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/204","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=204"}],"version-history":[{"count":8,"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/204\/revisions"}],"predecessor-version":[{"id":248,"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/204\/revisions\/248"}],"wp:attachment":[{"href":"https:\/\/llrwebpepites.in2p3.fr\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=204"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}