Articles with "collimation" as a keyword



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MHD Collimation Mechanism in Arched Flux Ropes Characterized Using Volumetric, Time‐Dependent B‐Vector Measurements

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Published in 2017 at "Geophysical Research Letters"

DOI: 10.1002/2017gl074505

Abstract: Laboratory measurements of B(x,t) in a volume enclosing portions of two arched flux ropes show flux rope collimation driven by gradients in axial current density. These measurements verify the three predictions of a proposed MHD… read more here.

Keywords: mechanism; flux ropes; mhd collimation; collimation ... See more keywords

Overranging and overbeaming measurement in area detector computed tomography: A method for simultaneous measurement in volume helical acquisition

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Published in 2019 at "Journal of Applied Clinical Medical Physics"

DOI: 10.1002/acm2.12650

Abstract: Abstract Purpose We propose a novel method to assess overbeaming and overranging, as well as the effect of reducing longitudinal exposure range, by using a dynamic z‐collimator in area detector computed tomography. Methods and materials… read more here.

Keywords: area detector; dynamic collimator; computed tomography; collimation ... See more keywords

Do radiographers collimate? A retrospective analysis of radiographic collimation of common musculoskeletal examinations at an adult trauma centre

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Published in 2022 at "Journal of Medical Radiation Sciences"

DOI: 10.1002/jmrs.630

Abstract: Collimation of the primary beam is an important factor in radiography to reduce dose and improve image quality. The introduction of larger detector plates in direct digital radiography (DR) allows the exposed area to be… read more here.

Keywords: collimation; collimate retrospective; analysis radiographic; radiographic collimation ... See more keywords

The dosimetric enhancement of GRID profiles using an external collimator in pencil beam scanning proton therapy.

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Published in 2022 at "Medical physics"

DOI: 10.1002/mp.15523

Abstract: PURPOSE The radiobiological benefits afforded by spatially fractionated (GRID) radiation therapy pairs well with the dosimetric advantages of proton therapy. Inspired by the emergence of energy-layer specific collimators in pencil beam scanning (PBS), this work… read more here.

Keywords: collimation; spot; beam; therapy ... See more keywords

The self-collimation effect induced by non-Hermitian acoustic systems

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Published in 2019 at "Applied Physics Letters"

DOI: 10.1063/1.5087162

Abstract: With the proposal of the concept of parity-time-symmetry, more and more exotic properties are being unearthed in non-Hermitian systems. In this work, we investigate the related acoustic feature and phenomenon in two-dimensional phononic crystals with… read more here.

Keywords: direction; collimation; hermitian systems; non hermitian ... See more keywords

Design of highly efficient polarization beam splitter based on self-collimation on Si platform

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Published in 2017 at "Journal of Modern Optics"

DOI: 10.1080/09500340.2016.1244294

Abstract: Abstract A highly efficient polarization beam splitter based on self-collimation phenomenon in 2D square array of air holes in Si background is presented. For the presented structural parameters, a broad bandwidth of Δω/ωc = 1.3%… read more here.

Keywords: efficient polarization; beam splitter; polarization beam; collimation ... See more keywords

Enhanced collimation of protons from intense-laser impact on foil-and-tube target with hydrocarbon coated backside

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Published in 2025 at "Plasma Physics and Controlled Fusion"

DOI: 10.1088/1361-6587/adba0e

Abstract: We investigate the proton collimation of foil-and-tube structured target with two-dimensional particle-in-cell simulation. The foil backside and the adjacent tube are coated with a thin hydrocarbon layer (HCL). It is found that the tube-wall HCL… read more here.

Keywords: collimation; hydrocarbon; target; foil ... See more keywords

Impact of Collimation on Radiation Exposure in Adult and Paediatric Digital X-Ray Imaging.

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Published in 2021 at "Radiation protection dosimetry"

DOI: 10.1093/rpd/ncab155

Abstract: This study aimed to evaluate the collimation practices and quantify the overexposure due to extensive X-ray field area. The study was carried out in four digital X-ray units (including one paediatric X-ray unit). A total… read more here.

Keywords: adult; field; collimation; digital ray ... See more keywords

Assessment of overranging as a function of pitch, collimation and rotation time for three of the most recent and widespread ct scans in France.

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Published in 2022 at "Radiation protection dosimetry"

DOI: 10.1093/rpd/ncac257

Abstract: PURPOSE to assess overranging (OR) as a function of pitch, collimation and rotation time for three commonly used CT models in France. METHODS OR was measured using XR-SP2 Gafchromic films (Ashland, USA) and computed from… read more here.

Keywords: rotation time; pitch; overranging function; collimation ... See more keywords

Study of a multi-pinhole collimation system based small-angle neutron scattering instrument at the Compact Pulsed Hadron Source

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Published in 2018 at "Journal of Applied Crystallography"

DOI: 10.1107/s1600576718013730

Abstract: The neutron flux of the Compact Pulsed Hadron Source (CPHS) is about 2–3 orders of magnitude lower than that of large neutron sources, which means that the beam intensity should be improved to achieve good… read more here.

Keywords: neutron; multi pinhole; collimation; pinhole collimation ... See more keywords

Optimizing neurointerventional procedures: an algorithm for embolization coil detection and automated collimation to enable dose reduction

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Published in 2024 at "Journal of Medical Imaging"

DOI: 10.1117/1.jmi.11.4.044003

Abstract: Abstract. Purpose Monitoring radiation dose and time parameters during radiological interventions is crucial, especially in neurointerventional procedures, such as aneurysm treatment with embolization coils. The algorithm presented detects the presence of these embolization coils in… read more here.

Keywords: detection; automated collimation; collimation; neurointerventional procedures ... See more keywords