Results 251 to 260 of about 1,344,359 (296)
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Radiology, 1974
A flexible lead chain has been designed for the shaping of irregular fields, primarily to achieve skin-sparing at the field edge. The device is simple and easy to use, allows better conformity to the desired contour than is usually achieved with standardized blocks, and avoids gaps in the shielding.
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A flexible lead chain has been designed for the shaping of irregular fields, primarily to achieve skin-sparing at the field edge. The device is simple and easy to use, allows better conformity to the desired contour than is usually achieved with standardized blocks, and avoids gaps in the shielding.
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Applied Optics, 1995
Several options for beam-shaping optics are presented, among them a novel single-element solution with toroidal surfaces in which the far-field angular spread of the outgoing beam is the average of the incoming divergences. The beam-shaping elements are judged with respect to their positioning and fabrication tolerances.
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Several options for beam-shaping optics are presented, among them a novel single-element solution with toroidal surfaces in which the far-field angular spread of the outgoing beam is the average of the incoming divergences. The beam-shaping elements are judged with respect to their positioning and fabrication tolerances.
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Medical Dosimetry, 1998
Field shaping for stereotactic radiosurgery and stereotactic radiotherapy has evolved from static field shaping techniques applied to static or arc fields and now includes dynamic field shaping definition which can be dynamically modified during the arc.
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Field shaping for stereotactic radiosurgery and stereotactic radiotherapy has evolved from static field shaping techniques applied to static or arc fields and now includes dynamic field shaping definition which can be dynamically modified during the arc.
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Beam shaping by holographic filters
Applied Optics, 1989The Gaussian profile of a laser beam can be changed by using a hologram with a suitable phase function. In particular a square and a line of uniform intensity can be generated from a Gaussian input beam.(AIP)
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SPIE Proceedings, 2014
Many commercial laser systems deliver a beam having a Gaussian intensity profile, however, numerous applications require other intensity profiles (top-hat, hollow beam, Bessel beam,…) which are in general obtained by converting the standard Gaussian beam (GB) through transparent diffractive optical elements (DOE). Laser beam shaping (LBS) by use of DOE’
A. Harfouche +3 more
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Many commercial laser systems deliver a beam having a Gaussian intensity profile, however, numerous applications require other intensity profiles (top-hat, hollow beam, Bessel beam,…) which are in general obtained by converting the standard Gaussian beam (GB) through transparent diffractive optical elements (DOE). Laser beam shaping (LBS) by use of DOE’
A. Harfouche +3 more
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On the Theory of Antenna Beam Shaping
Journal of Applied Physics, 1952The diffraction pattern of an aperture with amplitude distribution A(x) and phase function ψ(x) is examined for two cases: (1) controlled variation of the amplitude distribution with known uniform phase; (2) controlled variation of phase with known amplitude distribution.
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Robotic Radiosurgery with Beams of Adaptable Shapes
1995In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of fixed cross-section. The radiation source can only be moved along simple standardized paths. A new radiosurgical system based on a six degree-of-freedom robotic arm has been developed to overcome
Achim Schweikard +2 more
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SPIE Proceedings, 1991
A novel optical system is described which can be used to change the intensity profile of a laser beam without the increase in beam divergence which results from conventional techniques. The technique uses a telescope, the first lens of which is designed to introduce an amount of spherical aberration.
J. A. MacAndrew +5 more
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A novel optical system is described which can be used to change the intensity profile of a laser beam without the increase in beam divergence which results from conventional techniques. The technique uses a telescope, the first lens of which is designed to introduce an amount of spherical aberration.
J. A. MacAndrew +5 more
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1984
The highly directive beams attainable with microwave antennas have been utilized to achieve large antenna gain, precision direction finding, and a high degree of resolution of complex targets. The exploration of a wide angular region with such sharp beams requires an involved scanning operation in which the scanning time becomes a limiting factor. This
L. C. Van Atta, T. J. Keary
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The highly directive beams attainable with microwave antennas have been utilized to achieve large antenna gain, precision direction finding, and a high degree of resolution of complex targets. The exploration of a wide angular region with such sharp beams requires an involved scanning operation in which the scanning time becomes a limiting factor. This
L. C. Van Atta, T. J. Keary
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2020
Metasurfaces (MTS) are two-dimensional metamaterials (MTM) that are a periodic composition of thin, subwavelength and periodic inclusions widely known as unit-cells or meta-atoms. Amongst the vast range of research outcomes accomplished so far, there still is keen interest in the further investigation of metasurfaces to be utilized in various unique ...
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Metasurfaces (MTS) are two-dimensional metamaterials (MTM) that are a periodic composition of thin, subwavelength and periodic inclusions widely known as unit-cells or meta-atoms. Amongst the vast range of research outcomes accomplished so far, there still is keen interest in the further investigation of metasurfaces to be utilized in various unique ...
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