The Experts below are selected from a list of 183813 Experts worldwide ranked by ideXlab platform

Yuichiro Kamino - One of the best experts on this subject based on the ideXlab platform.

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB{sub 6}) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and themore » average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mmx0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-I{sub b} (mA)x0.00808 (MeV/mA), where I{sub b} is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.« less

  • development of a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    International Journal of Radiation Oncology Biology Physics, 2006
    Co-Authors: Yuichiro Kamino, Kenji Takayama, Masaki Kokubo, Yuichiro Narita, Etsuro Hirai, Noriyuki Kawawda, Takashi Mizowaki, Yasushi Nagata, Takehiro Nishidai
    Abstract:

    Purpose: To develop and evaluate a new four-Dimensional Image-guided radiotherapy system, which enables precise setup, real-time tumor tracking, and pursuit irradiation. Methods and Materials: The system has an innovative gimbaled X-ray head that enables small-angle (±2.4°) rotations (pan and tilt) along the two orthogonal gimbals. This design provides for both accurate beam positioning at the isocenter by actively compensating for mechanical distortion and quick pursuit of the target. The X-ray head is composed of an ultralight C-band linear accelerator and a multileaf collimator. The gimbaled X-ray head is mounted on a rigid O-ring structure with an on-board imaging subsystem composed of two sets of kilovoltage X-ray tubes and flat panel detectors, which provides a pair of radiographs, cone beam computed tomography Images useful for Image guided setup, and real-time fluoroscopic monitoring for pursuit irradiation. Results: The root mean square accuracy of the static beam positioning was 0.1 mm for 360° of O-ring rotation. The dynamic beam response and positioning accuracy was ±0.6 mm for a 0.75 Hz, 40-mm stroke and ±0.4 mm for a 2.0 Hz, 8-mm stroke. The quality of the Images was encouraging for using the tomography-based setup. Fluoroscopic Images were sufficient for monitoring and tracking lung tumors. Conclusions: Key functions and capabilities of our new system are very promising for precise Image-guided setup and for tracking and pursuit irradiation of a moving target.

Junzo Ishikawa - One of the best experts on this subject based on the ideXlab platform.

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB{sub 6}) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and themore » average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mmx0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-I{sub b} (mA)x0.00808 (MeV/mA), where I{sub b} is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.« less

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

Masaki Kokubo - One of the best experts on this subject based on the ideXlab platform.

  • dosimetric characterization of a multileaf collimator for a new four Dimensional Image guided radiotherapy system with a gimbaled x ray head mhi tm2000
    Medical Physics, 2010
    Co-Authors: Mitsuhiro Nakamura, Kenji Takayama, Masaki Kokubo, Takashi Mizowaki, A Sawada, Y Ishihara, Shuji Kaneko, Mikiko Yamashita, H Tanabe, Masahiro Hiraoka
    Abstract:

    Purpose: To present the dosimetric characterization of a multileaf collimator (MLC) for a new four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head, MHI-TM2000. Methods: MHI-TM2000 has an x-ray head composed of an ultrasmall linear accelerator guide and a system-specific MLC. The x-ray head can rotate along the two orthogonal gimbals (pan and tilt rotations) up to {+-}2.5 deg., which swings the beam up to {+-}41.9 mm in each direction from the isocenter on the isocenter plane perpendicular to the beam. The MLC design is a single-focus type, has 30 pairs of 5 mm thick leaves at the isocenter, and produces a maximum field size of 150x150 mm{sup 2}. Leaf height and length are 110 and 260 mm, respectively. Each leaf end is circular, with a radius of curvature of 370 mm. The distance that each leaf passes over the isocenter is 77.5 mm. Radiation leakage between adjacent leaves is minimized by an interlocking tongue-and-groove (T and G) arrangement with the height of the groove part 55 mm. The dosimetric characterizations including field characteristics, leaf position accuracy, leakage, and T and G effect were evaluated using a well-commissioned 6 MV photon beam, EDR2 films (Kodak, Rochester, NY), and water-equivalent phantoms.more » Furthermore, the field characteristics and leaf position accuracy were evaluated under conditions of pan or tilt rotation. Results: The differences between nominal and measured field sizes were within {+-}0.5 mm. Although the penumbra widths were greater with wider field size, the maximum width was <5.5 mm even for the fully opened field. Compared to the results of field characteristics without pan or tilt rotation, the variation in field size, penumbra width, flatness, and symmetry was within {+-}1 mm/1% at the maximum pan or tilt rotational angle. The leaf position accuracy was 0.0{+-}0.1 mm, ranging from -0.3 to 0.2 mm at four gantry angles of 0 deg., 90 deg., 180 deg., and 270 deg. with and without pan or tilt rotation. The interleaf leakage was up to 0.21%, whereas the intraleaf leakage was <0.12%. T and G decreased the doses by 10.7%, on average. Conclusions: This study demonstrated that MHI-TM2000 has the capability for high leaf position accuracy and low leakage, leading to highly accurate intensity-modulated radiotherapy delivery. Furthermore, substantial changes in the dosimetric data on field characteristics and leaf position accuracy were not observed even at the maximum pan or tilt rotation.« less

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB{sub 6}) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and themore » average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mmx0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-I{sub b} (mA)x0.00808 (MeV/mA), where I{sub b} is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.« less

  • development of a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    International Journal of Radiation Oncology Biology Physics, 2006
    Co-Authors: Yuichiro Kamino, Kenji Takayama, Masaki Kokubo, Yuichiro Narita, Etsuro Hirai, Noriyuki Kawawda, Takashi Mizowaki, Yasushi Nagata, Takehiro Nishidai
    Abstract:

    Purpose: To develop and evaluate a new four-Dimensional Image-guided radiotherapy system, which enables precise setup, real-time tumor tracking, and pursuit irradiation. Methods and Materials: The system has an innovative gimbaled X-ray head that enables small-angle (±2.4°) rotations (pan and tilt) along the two orthogonal gimbals. This design provides for both accurate beam positioning at the isocenter by actively compensating for mechanical distortion and quick pursuit of the target. The X-ray head is composed of an ultralight C-band linear accelerator and a multileaf collimator. The gimbaled X-ray head is mounted on a rigid O-ring structure with an on-board imaging subsystem composed of two sets of kilovoltage X-ray tubes and flat panel detectors, which provides a pair of radiographs, cone beam computed tomography Images useful for Image guided setup, and real-time fluoroscopic monitoring for pursuit irradiation. Results: The root mean square accuracy of the static beam positioning was 0.1 mm for 360° of O-ring rotation. The dynamic beam response and positioning accuracy was ±0.6 mm for a 0.75 Hz, 40-mm stroke and ±0.4 mm for a 2.0 Hz, 8-mm stroke. The quality of the Images was encouraging for using the tomography-based setup. Fluoroscopic Images were sufficient for monitoring and tracking lung tumors. Conclusions: Key functions and capabilities of our new system are very promising for precise Image-guided setup and for tracking and pursuit irradiation of a moving target.

Masahiro Hiraoka - One of the best experts on this subject based on the ideXlab platform.

  • dosimetric characterization of a multileaf collimator for a new four Dimensional Image guided radiotherapy system with a gimbaled x ray head mhi tm2000
    Medical Physics, 2010
    Co-Authors: Mitsuhiro Nakamura, Kenji Takayama, Masaki Kokubo, Takashi Mizowaki, A Sawada, Y Ishihara, Shuji Kaneko, Mikiko Yamashita, H Tanabe, Masahiro Hiraoka
    Abstract:

    Purpose: To present the dosimetric characterization of a multileaf collimator (MLC) for a new four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head, MHI-TM2000. Methods: MHI-TM2000 has an x-ray head composed of an ultrasmall linear accelerator guide and a system-specific MLC. The x-ray head can rotate along the two orthogonal gimbals (pan and tilt rotations) up to {+-}2.5 deg., which swings the beam up to {+-}41.9 mm in each direction from the isocenter on the isocenter plane perpendicular to the beam. The MLC design is a single-focus type, has 30 pairs of 5 mm thick leaves at the isocenter, and produces a maximum field size of 150x150 mm{sup 2}. Leaf height and length are 110 and 260 mm, respectively. Each leaf end is circular, with a radius of curvature of 370 mm. The distance that each leaf passes over the isocenter is 77.5 mm. Radiation leakage between adjacent leaves is minimized by an interlocking tongue-and-groove (T and G) arrangement with the height of the groove part 55 mm. The dosimetric characterizations including field characteristics, leaf position accuracy, leakage, and T and G effect were evaluated using a well-commissioned 6 MV photon beam, EDR2 films (Kodak, Rochester, NY), and water-equivalent phantoms.more » Furthermore, the field characteristics and leaf position accuracy were evaluated under conditions of pan or tilt rotation. Results: The differences between nominal and measured field sizes were within {+-}0.5 mm. Although the penumbra widths were greater with wider field size, the maximum width was <5.5 mm even for the fully opened field. Compared to the results of field characteristics without pan or tilt rotation, the variation in field size, penumbra width, flatness, and symmetry was within {+-}1 mm/1% at the maximum pan or tilt rotational angle. The leaf position accuracy was 0.0{+-}0.1 mm, ranging from -0.3 to 0.2 mm at four gantry angles of 0 deg., 90 deg., 180 deg., and 270 deg. with and without pan or tilt rotation. The interleaf leakage was up to 0.21%, whereas the intraleaf leakage was <0.12%. T and G decreased the doses by 10.7%, on average. Conclusions: This study demonstrated that MHI-TM2000 has the capability for high leaf position accuracy and low leakage, leading to highly accurate intensity-modulated radiotherapy delivery. Furthermore, substantial changes in the dosimetric data on field characteristics and leaf position accuracy were not observed even at the maximum pan or tilt rotation.« less

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB{sub 6}) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and themore » average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mmx0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-I{sub b} (mA)x0.00808 (MeV/mA), where I{sub b} is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.« less

  • development of an ultrasmall c band linear accelerator guide for a four Dimensional Image guided radiotherapy system with a gimbaled x ray head
    Medical Physics, 2007
    Co-Authors: Yuichiro Kamino, Masaki Kokubo, Etsuro Hirai, Sadao Miura, Ichiro Yamashita, Masahiro Hiraoka, Junzo Ishikawa
    Abstract:

    We are developing a four-Dimensional Image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

Dominique Bernard - One of the best experts on this subject based on the ideXlab platform.

  • three Dimensional Image correlation from x ray computed tomography of solid foam
    Composites Part A-applied Science and Manufacturing, 2008
    Co-Authors: Stephane Roux, Francois Hild, Philippe Viot, Dominique Bernard
    Abstract:

    A new methodology is proposed to estimate 3D displacement fields from pairs of Images obtained from X-ray computed microtomography (XCMT). Contrary to local approaches, a global approach is followed herein that evaluates continuous displacement fields. Although any displacement basis may be considered, the procedure is specialized to finite element shape functions. The method is illustrated with the analysis of a compression test on a polypropylene solid foam (independently studied in a companion paper). A good stability of the measured displacement field is obtained for cubic element sizes ranging from 16 to 6 voxels.

  • Three Dimensional Image correlation from X-Ray computed tomography of solid foam
    Composites Part A: Applied Science and Manufacturing, 2008
    Co-Authors: Stephane Roux, Francois Hild, Philippe Viot, Dominique Bernard
    Abstract:

    A new methodology is proposed to estimate 3D displacement fields from pairs of Images obtained from X-Ray Computed Micro Tomography (XCMT). Contrary to local approaches, a global approach is followed herein that evaluates {\em continuous} displacement fields. Although any displacement basis could be considered, the procedure is specialized to finite element shape functions. The method is illustrated with the analysis of a compression test on a polypropylene solid foam (independently studied in a companion paper). A good stability of the measured displacement field is obtained for cubic element sizes ranging from $16$ voxels to $6$ voxels.