Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

Seismic Exploration Using Active Sources at Kuchierabujima Volcano, Southwest Japan

Seismic exploration using artificial sources was conducted at Kuchierabujima volcano, southwest Japan in November 2004 by 40 participants from 9 national universities andJapan Meteorological Agency to investigate the subsurface seismic structure. The exploration was the 11th joint experiment under the National Project for Prediction of Volcanic Eruptions. A total of 183 temporal stations equippedwith a 2 Hz vertical component seismometer (including 75 3component seismometers) and a portable data logger were deployed on Kuchierabu Island. Dynamite shots with charges of 10-115 kg were detonated at 19 locations, and seismic signals were successfully recorded. To reveal the P-wave velocity structure, 2955 arrival times of the first motion were picked from the seismograms, and 2187 were classified into ranks A and B. From the record sections and the arrival time data, characteristics reflecting the geological structure were identified. Refracted waves of 5 km/s were observed at stations＞5km from the shot points. Apparent velocities near the shot points depend on the surface geology around the shots. P-wave arrived earlier at stations near the summits. Strongly scattered waves were observed similarly near the summits

多種多様な診断及び治療用放射性薬剤の安定的製造

先進核医学基盤研究部では、診断や治療に有用な放射性核種の製造開発研究、放射性薬剤の製造開発研究、それらの分析技術の開発研究を行っており、放射性核種製造及び放射性薬剤製造技術を向上し続けている。さらに、我々は、多種多様な診断及び治療用の放射性核種及び放射性薬剤をQST内研究部やQST病院だけでなく外部の大学、研究機関、企業にも安定的に提供し続けている。また、我々は、高品位の放射性核種及び薬剤を安定的に提供し続けるために、関連する設備、装置及び機器の維持管理も常時確実に行っている。本報告では、放射性核種及び薬剤製造に関連する設備及び装置について紹介するとともに、本年度の放射性核種及び薬剤の製造回数と提供状況についても報告する。第１回千葉地区 技術と支援の活動報告

Seismic Exploration by Using Active Sources at Kuchierabujima Volcano, Southwest Japan

口永良部島火山の浅部構造を明らかにすることを目的として人工地震探査を2004年11月に行った。183点の地震観測点(内3成分75点)を設置し，19点において爆破を行った。初動の読み取りを行った結果，2955個の検測値が得られ，そのうち2187個はAおよびBランクの精度のよいものであった。発破点付近の見かけ速度は近傍の地質構造を強く反映したものであるが，発破点から距離5km付近からは見かけ速度5km/sの屈折波が観測された．新岳・古岳の山体では走時が早い傾向が認められるとともに強い散乱波が観測された。Seismic exploration using artificial sources was conducted at Kuchierabujima volcano, southwest Japan in November 2004 to investigate subsurface seismic structure. A total of 183 temporal stations equipped with a 2Hz vertical component seismometer (including 75 3-component seismometers) and a portable data logger were deployed. Dynamite shots with charges of 10-115kg were detonated at 19 locations. To reveal shallow structure of the volcano, 2955 arrival times of the first motion were picked from the seismograms and 2187 were classified into ranks A and B. Refracted waves of 5km/s were observed at stations >5 km apart from the shot points. Apparent velocities near the shot points depend on surface geology around the shots. P-wave arrived earlier at stations near the summits. Strongly scattered waves were observed near the summits.口永良部島火山の浅部構造を明らかにすることを目的として人工地震探査を2004年11月に行った。183点の地震観測点(内3成分75点)を設置し，19点において爆破を行った。初動の読み取りを行った結果，2955個の検測値が得られ，そのうち2187個はAおよびBランクの精度のよいものであった。発破点付近の見かけ速度は近傍の地質構造を強く反映したものであるが，発破点から距離5km付近からは見かけ速度5km/sの屈折波が観測された．新岳・古岳の山体では走時が早い傾向が認められるとともに強い散乱波が観測された。Seismic exploration using artificial sources was conducted at Kuchierabujima volcano, southwest Japan in November 2004 to investigate subsurface seismic structure. A total of 183 temporal stations equipped with a 2Hz vertical component seismometer (including 75 3-component seismometers) and a portable data logger were deployed. Dynamite shots with charges of 10-115kg were detonated at 19 locations. To reveal shallow structure of the volcano, 2955 arrival times of the first motion were picked from the seismograms and 2187 were classified into ranks A and B. Refracted waves of 5km/s were observed at stations >5 km apart from the shot points. Apparent velocities near the shot points depend on surface geology around the shots. P-wave arrived earlier at stations near the summits. Strongly scattered waves were observed near the summits

永良部島火山における人工地震探査 : 探査の概要と初動の走時について

Seismic exploration using artificial sources was conducted at Kuchierabujima volcano, southwest Japan in November 2004 by 40 participants from 9 national universities andJapan Meteorological Agency to investigate the subsurface seismic structure. The exploration was the 11th joint experiment under the National Project for Prediction of Volcanic Eruptions. A total of 183 temporal stations equippedwith a 2 Hz vertical component seismometer (including 75 3component seismometers) and a portable data logger were deployed on Kuchierabu Island. Dynamite shots with charges of 10-115 kg were detonated at 19 locations, and seismic signals were successfully recorded. To reveal the P-wave velocity structure, 2955 arrival times of the first motion were picked from the seismograms, and 2187 were classified into ranks A and B. From the record sections and the arrival time data, characteristics reflecting the geological structure were identified. Refracted waves of 5 km/s were observed at stations＞5km from the shot points. Apparent velocities near the shot points depend on the surface geology around the shots. P-wave arrived earlier at stations near the summits. Strongly scattered waves were observed similarly near the summits