{"created":"2023-07-25T10:22:46.655122+00:00","id":1310,"links":{},"metadata":{"_buckets":{"deposit":"9f406765-6a29-4f03-b136-3c9adae5cade"},"_deposit":{"created_by":8,"id":"1310","owners":[8],"pid":{"revision_id":0,"type":"depid","value":"1310"},"status":"published"},"_oai":{"id":"oai:pu-hiroshima.repo.nii.ac.jp:00001310","sets":["106:128:154:129"]},"author_link":["3464","4456","4457","1330"],"item_10002_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2005-03","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"40","bibliographicPageStart":"31","bibliographicVolumeNumber":"5","bibliographic_titles":[{"bibliographic_title":"広島県立保健福祉大学誌人間と科学"},{"bibliographic_title":"Journal of Hiroshima Prefectural College of Health Sciences, humanity and science","bibliographic_titleLang":"en"}]}]},"item_10002_description_19":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_10002_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Mean energy of neutrons from an electron linear accelerator (LINAC) was experimentally estimated. The LINAC is used for radiation treatments at the Hiroshima Prefectural College of Health Sciences. The thermal neutron fluence rate was determined measuring the gamma rays from ^<116ml>In (half-life of 54.29 min) induced in indium foil exposed to 10 MV X-rays. The mean energy of the neutrons was estimated from the attenuation coefficient of the thermal neutron fluence rates in a polyethylene block, the surface of which was located at the isocenter. The block was surrounded by 10 cm of boric acid layers, except for the upper surface. In the estimations, it was assumed that all thermal neutrons in the block came from the head of the LINAC. Gamma rays from ^<116ml>In were measured by a Ge semiconductor detector, which was shielded by lead blocks thicker than 15 cm. The thermal neutron fluence rate was (7.1±0.4)×10^8 m^<-2>s^<-1> at a 2 cm depth of the polyethylene block, when the X-ray dose rate was 2 Gy/min at the reference depth for radiation therapy and the field size was 10cm×10cm. Under the same condition, the mean energy of the neutrons from the head of the LINAC was estimated to be 1.22±0.02 MeV. The mean energy increased to 1.34±0.03 MeV through the 5 cm boric acid filter, and decreased to 1.00±0.03 MeV through a 3 cm copper filter. This can be explained by the facts that the boric acids absorbed the incident thermal neutrons, and that the copper plate moderated the incident fast neutrons. The mean neutron energies in 5cm×5cm, 10cm×10cm and 15cm×15cm field sizes were approximately coincident to each other.","subitem_description_language":"en","subitem_description_type":"Abstract"},{"subitem_description":"放射線治療に用いられる医療用電子線線形加速器を加速エネルギー10 MeVで運転し治療用x線を発生させる時に光核反応によって発生する熱中性子のフルエンス率と全中性子の平均エネルギーを実験的に推定した。熱中性子フルエンス率は中性子を照射したインジウム(In)金属箔の中で生じた^<116ml>In(半減期,54.29 min)からのγ線を測定して推定した。中性子平均エネルギーは熱中性子フルエンス率の20cm厚のポリエチレンブロックにおける熱中性子フルエンス率の減弱係数から推定した。ポリエチレンブロックの表面の中心はアイソセンターに置いた。ポリエチレンブロックは側面と底面(治療台の下)に10cm厚のホウ酸を置き熱中性子を遮蔽した。中性子平均エネルギーの推定において,ポリエチレンブロックの熱中性子は全て加速器のヘッド部からきたものと仮定した。γ線は15cm厚の鉛ブロックで遮蔽されたGe検出器を用いて測定した。測定した^<116ml>In生成率から推定した熱中性子フルエンス率は,照射野サイズ10cm×10cm,線量率2Gy/minで照射中のポリエチレンブロック表面から2cmの深さで(7.1±0.4)×10^8 m^<-2>s^<-1>であった。ポリエチレンによる熱中性子フルエンス率の減弱曲線から推定したポリエチレンブロック表面に入射した中性子の平均エネルギーは照射野10×10cm^2で1.22±0.02 MeVであった。この中性子平均エネルギーは3cm厚の銅フィルターによって1.00±0.03 MeVまでに下がった。一方,5cm厚のホウ酸フィルターによって,1.34±0.03 MeVまで上がった。この結果は,銅フィルターによる速中性子の減速,ならびにホウ酸フィルターによる熱中性子の吸収の効果を表していると考えられる。照射野を5cm×5cm,10cm×10cmならびに15cm×15cmに変えて調べた中性子の平均エネルギーはほぼ一致していた。","subitem_description_language":"ja","subitem_description_type":"Abstract"}]},"item_10002_description_6":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"原著\nOriginal Article\n国立情報学研究所で電子化","subitem_description_type":"Other"}]},"item_10002_publisher_8":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"広島県立保健福祉大学"}]},"item_10002_source_id_11":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AA11568026","subitem_source_identifier_type":"NCID"}]},"item_10002_source_id_9":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"1346-3217","subitem_source_identifier_type":"PISSN"}]},"item_10002_version_type_20":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"加藤, 一生","creatorNameLang":"ja"},{"creatorName":"カトウ, カズオ","creatorNameLang":"ja-Kana"},{"creatorName":"KATO, Kazuo","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"3464","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"尾美, 賜","creatorNameLang":"ja"},{"creatorName":"オミ, メグミ","creatorNameLang":"ja-Kana"},{"creatorName":"OMI, Megumi","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"4456","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"田中, 茂久","creatorNameLang":"ja"},{"creatorName":"タナカ, シゲヒサ","creatorNameLang":"ja-Kana"},{"creatorName":"TANAKA, Shigehisa","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"4457","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"小山, 矩","creatorNameLang":"ja"},{"creatorName":"コヤマ, タダシ","creatorNameLang":"ja-Kana"},{"creatorName":"KOYAMA, Tadashi","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"1330","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2023-04-18"}],"displaytype":"detail","filename":"KJ00004432263.pdf","filesize":[{"value":"447.1 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"KJ00004432263.pdf","url":"https://pu-hiroshima.repo.nii.ac.jp/record/1310/files/KJ00004432263.pdf"},"version_id":"398bf8a2-5879-43f4-b63b-ffeecafe134d"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"医療用電子線線形加速器で発生する中性子線の平均エネルギー","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"医療用電子線線形加速器で発生する中性子線の平均エネルギー","subitem_title_language":"ja"},{"subitem_title":"Mean Energy of Neutrons from an Electron Linear Accelerator for Radiation Therapy","subitem_title_language":"en"}]},"item_type_id":"10002","owner":"8","path":["129"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2023-04-18"},"publish_date":"2023-04-18","publish_status":"0","recid":"1310","relation_version_is_last":true,"title":["医療用電子線線形加速器で発生する中性子線の平均エネルギー"],"weko_creator_id":"8","weko_shared_id":-1},"updated":"2023-11-08T06:33:55.439252+00:00"}