نتایج جستجو برای: optical collimator

تعداد نتایج: 269265  

2011
Mattijs Elschot Johannes Franciscus Wilhelmus Nijsen Alida Johanna Dam Hugo Wilhelmus Antonius Maria de Jong

BACKGROUND Scintillation camera imaging is used for treatment planning and post-treatment dosimetry in liver radioembolization (RE). In yttrium-90 (90Y) RE, scintigraphic images of technetium-99m (99mTc) are used for treatment planning, while 90Y Bremsstrahlung images are used for post-treatment dosimetry. In holmium-166 (166Ho) RE, scintigraphic images of 166Ho can be used for both treatment p...

2017
Shinro Matsuo Kenichi Nakajima Koichi Okuda Masaya Kawano Takehiro Ishikawa Tetsuo Hosoya Seigo Kinuya

Background. Although heart-to-mediastinum (H/M) ratio in a planner image has been used for practical quantification for I-metaiodobenzylguanidine (MIBG) imaging, standardization of the parameter is not yet established. We hypothesized that the value of H/M can be standardized to the various types of camera-collimator combinations. Methods and Results. Standard phantoms consisting of the heart, ...

جوهری دها, فریبا, افتخاری, محمد, رجبی, حسین, طالشی آهنگری, هادی,

Background and purpose: Imaging which is used in nuclear medicine is done using emit gamma rays whereas therapy in nuclear medicine is performed by applying radionuclide’s which emit beta radiation. Using Bremsstrahlung is a new field which is recently introduced in imaging. In the Bremsstrahlung imaging, collimator design should not be based on energy peak and whole energy spectrum should be c...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
Peter R H Stark Allison E Halleck Dale N Larson

The optical diffraction limit has been the dominant barrier to achieving higher optical resolution in the fields of microscopy, photolithography, and optical data storage. We present here an approach toward imaging below the diffraction barrier. Through the exposure of photosensitive films placed a finite and known distance away from nanoscale, zero-mode apertures in thin metallic films, we sho...

2001
Josef Frisch Eric Doyle Knut Skarpaas

The high beam intensities in the next linear collider can damage the collimation system jaws if a failure of the electronic machine protection system allows the acceleration of a mis-launched pulse. We are developing a prototype collimator that will allow a new jaw surface to be moved into place after beam damage. We are also developing a prototype collimator based on continuously reforming the...

2017
Mohammed S. Alqahtani John E. Lees Sarah L. Bugby Piyal Samara-Ratna Aik H. Ng Alan C. Perkins

BACKGROUND A prototype anthropomorphic head and neck phantom has been designed to simulate the adult head and neck anatomy including some internal organs and tissues of interest, such as thyroid gland and sentinel lymph nodes (SLNs). The design of the head and neck phantom includes an inner jig holding the simulated SLNs and thyroid gland. The thyroid gland structure was manufactured using thre...

2008
James Bauer Sajeev John

We demonstrate high efficiency, broadband coupling between photonic crystal waveguides and photonic crystal fibers PCFs using simple two-dimensional design models. We demonstrate an effective largebandwidth small-footprint beam collimator for light exiting a two-dimensional subwavelength scale photonic crystal waveguide consisting of an air core. This collimator relies on destructive interferen...

Journal: :Transactions of the Optical Society 1917

2007
Tadashi Nakajima

A conceptual design for a fringe-tracking interferometric array is presented. Unlike the conventional design which splits N beams of an N aperture array and combines them into N(N 1)/2 fringes, only N broad-band fringes are formed and measured in the fringe-tracking channel to determine N 1 instantaneous piston di erences. Beam splitting and combining are accomplished by optics composed of a co...

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