Relevant bibliographies by topics / Radiation shaping

Academic literature on the topic 'Radiation shaping'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Radiation shaping"

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Zweigle, J. "Dynamical simulations of the shaping of PNe including radiation effects." Symposium - International Astronomical Union 180 (1997): 294. http://dx.doi.org/10.1017/s0074180900131110.

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In order to investigate the shaping of aspherical planetary nebulae the gasdynamical conservation laws of mass, momentum and energy including radiation effects are solved numerically in twodimensional, spherical coordinates. The simulations describe the dynamical interaction of a fast, tenuous, spherically symmetric wind from the central star with the slow, dense, axisymmetric AGB-wind remnant and include photoionization, collisional ionization, collisional excitation, radiative recombination and forbidden line emission as radiation effects.
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Decataldo, D., A. Lupi, A. Ferrara, A. Pallottini, and M. Fumagalli. "Shaping the structure of a GMC with radiation and winds." Monthly Notices of the Royal Astronomical Society 497, no. 4 (August 11, 2020): 4718–32. http://dx.doi.org/10.1093/mnras/staa2326.

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ABSTRACT We study the effect of stellar feedback (photodissociation/ionization, radiation pressure, and winds) on the evolution of a Giant Molecular Cloud (GMC), by means of a 3D radiative transfer, hydrosimulation implementing a complex chemical network featuring H2 formation and destruction. We track the formation of individual stars with mass $M\gt 1\, {\rm M}_{\odot }$ with a stochastic recipe. Each star emits radiation according to its spectrum, sampled with 10 photon bins from near-infrared to extreme ultraviolet bands; winds are implemented by energy injection in the neighbouring cells. We run a simulation of a GMC with mass $M=10^5\, {\rm M}_{\odot }$, following the evolution of different gas phases. Thanks to the simultaneous inclusion of different stellar feedback mechanisms, we identify two stages in the cloud evolution: (1) radiation and winds carve ionized, low-density bubbles around massive stars, while FUV radiation dissociates most H2 in the cloud, apart from dense, self-shielded clumps; (2) rapid star formation (SFR$\simeq 0.1\, {\rm M}_{\odot }\, {\rm yr}^{-1}$) consumes molecular gas in the dense clumps, so that UV radiation escapes and ionizes the remaining $\mathrm{H\,{\small I}}$ gas in the GMC. H2 is exhausted in 1.6 Myr, yielding a final star formation efficiency of 36 per cent. The average intensity of FUV and ionizing fields increases almost steadily with time; by the end of the simulation (t = 2.5 Myr) we find 〈G0〉 ≃ 103 (in Habing units), and a ionization parameter 〈Uion〉 ≃ 102, respectively. The ionization field has also a more patchy distribution than the FUV one within the GMC. Throughout the evolution, the escape fraction of ionizing photons from the cloud is fion, esc ≲ 0.03.
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Ayyangar, Komanduri. "Automatic field shaping for conformal radiation therapy." Computer Methods and Programs in Biomedicine 42, no. 4 (April 1994): 223–32. http://dx.doi.org/10.1016/0169-2607(94)90095-7.

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Jarrahi, M. "Terahertz Radiation-Band Engineering Through Spatial Beam-Shaping." IEEE Photonics Technology Letters 21, no. 13 (July 2009): 830–32. http://dx.doi.org/10.1109/lpt.2009.2019620.

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Eichenberger, Michael, Flavio Giorgianni, Nick Sauerwein, Carlo Vicario, and Christoph P. Hauri. "Deformable mirror for wavefront shaping of infrared radiation." Optics Letters 43, no. 9 (April 24, 2018): 2062. http://dx.doi.org/10.1364/ol.43.002062.

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Wrona, Stanislaw, Marek Pawelczyk, and Xiaojun Qiu. "Shaping the acoustic radiation of a vibrating plate." Journal of Sound and Vibration 476 (June 2020): 115285. http://dx.doi.org/10.1016/j.jsv.2020.115285.

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Gupta, Sanjay, and Asmita Sharda. "Chromatin landscape: Re-shaping radiation biology and oncology." Journal of Radiation and Cancer Research 8, no. 3 (2017): 121. http://dx.doi.org/10.4103/jrcr.jrcr_36_17.

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Tsvetkov, A. D., and N. I. Potapova. "'Spekforms' — sintered components for shaping laser radiation wavefronts." Quantum Electronics 24, no. 1 (January 31, 1994): 78–80. http://dx.doi.org/10.1070/qe1994v024n01abeh000024.

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Wang, Lei, Sergey Kruk, Lei Xu, Mohsen Rahmani, Daria Smirnova, Alexander Solntsev, Ivan Kravchenko, Dragomir Neshev, and Yuri Kivshar. "Shaping the third-harmonic radiation from silicon nanodimers." Nanoscale 9, no. 6 (2017): 2201–6. http://dx.doi.org/10.1039/c6nr09702b.

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Cotter, G. W. "Adjustable field shaping for external-beam radiation therapy." Radiology 174, no. 3 (March 1990): 892–93. http://dx.doi.org/10.1148/radiology.174.3.2305076.

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Dissertations / Theses on the topic "Radiation shaping"

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Čelanović, Ivan. "Thermophotovoltaics : shaping the flow of thermal radiation." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37918.

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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.
Includes bibliographical references (p. 121-123).
This thesis explores the modeling, design, and optimization of photonic crystals as spectral control components for high-performance thermophotovoltaic (TPV) power conversion. In particular, we focus on the use of one-dimensional and two dimensional photonic crystals as optical filters and selective thermal emitters for thermophotovoltaic and micro-thermophotovoltaic (micro-TPV)) applications. In addition, we explore fundamental limitations of photonic crystal thermal emitters and provide new insights into the limiting power transfer mechanisms that are relevant for TPV, micro-TPV, lighting and sensor applications. Ideal thermodynamic models that capture dominant power transfer mechanism for TPV and micro-TPV case, are developed and used for the design, optimization and system performance estimation of TPV systems with photonic-crystals. Furthermore, we propose for the first time two new classes of narrow-band thermal emitters that use the resonant cavity effect. The first type of narrow-band thermal emitters rely on vertical-cavity to enhance the thermal emission of highly reflective materials (e.g metals). This class of emitters was named the vertical cavity enhanced resonant thermal emitter (VERTE).
(cont.) The second type of resonant thermal emitters rely on guided resonances in a two-dimensional photonic crystal slab to enhance the emittance of a high-dielectric low-absorption material (e.g. silicon). Both types of resonant thermal emission sources are quasi-monochromatic, and partially-coherent thermal sources that hold great promise for applications ranging from highly-efficient TPV systems to near-IR and IR sensors. Finally, experimentally measured spectral characteristics of fabricated one-dimensional and two-dimensional photonic-crystals show excellent correlation with simulation results. It was shown that a TPV system comprising of the proposed front-side filter and selective thermal emitter exhibits a three-fold enhancement in efficiency over the conventional TPV systems.
by Ivan Čelanović.
Sc.D.
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Van, der Walt Jacobus Gert. "Radiation field shaping through low temperature thermal-spray in radiotheraphy." Thesis, Bloemfontein : Central University of Technology, Free State, 2009. http://hdl.handle.net/11462/116.

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Thesis (D. Tech.) -- Central University of Technology, Free State, 2009
Superficial cancerous lesions are commonly treated through low energy X-ray or electron radiation in radiotherapy. The treatment units that produce the radiation are equipped with square, rectangular and round applicators of different sizes. These applicators attach to the treatment units and define the radiation field size applied during treatment. An applicator is chosen to fit the shape of the cancerous lesion on the patient as closely as possible. Since cancerous lesions are irregular in shape, there will always be an area of healthy tissue between the edge of the lesion and the edge of the standard field shape. This healthy tissue will be irradiated along with the lesion during treatment which is undesirable since the cancer wound heals through reparative growth of the surrounding healthy tissue after treatment. Traditional techniques that were developed to shield this healthy tissue and thus shape the radiation field to the shape of the lesion present various shortcomings. This study introduces a new thermal-spray process for producing radiation field shaping shields which overcomes most of the shortcomings encountered with the traditional field shaping techniques. Since none of the commercially available thermal-spray equipment could be used to produce field shaping shields, new thermal-spray equipment was designed and fabricated tailor made to the application. Different techniques to determine the contours of the treatment area on the patient were investigated. These included a patient contact technique using a plaster bandage impression and a non-contact technique using 3D laser scanning. From the plaster bandage impression a plaster model can be produced onto which a high density low melt material such as Wood’ s alloy can be thermally sprayed to produce a field shaping mask. A model can also be produced from the 3D laser scanning data through laser sintering (LS) in nylon polyamide powder or through computer numerical controlled (CNC) milling in a block of low density polyurethane. The thermal-spray technique was evaluated by comparing the field shaping ability of radiation shields produced through the technique to the field shaping ability of shields produced through the traditional techniques. Radiographic film was used for this purpose and the results are presented in the form of isodensity charts. The required thicknesses of thermal-sprayed field shaping masks to shield radiation of various energies were also determined. The thicknesses were determined through radiation transmission measurements of known thicknesses of sprayed sheets of Wood’ s alloy. X-ray imaging showed that there were no defects present within thermal-sprayed layers of Wood’ s alloy that may negatively affect the shielding ability of masks produced through the technique.
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Scott, H. M. "Near field modification techniques for pattern shaping in antenna elements and arrays." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269176.

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Wanis, Sameh Sadarous. "Tailored Force Fields for Flexible Fabrication." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10540.

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The concept of tailored force fields is seen as an enabler for the construction of large scale space structures. Manufacturing would take place in space using in-situ resources thereby eliminating the size and weight restriction commonly placed on space vehicles and structures. This thesis serves as the first investigation of opening the way to a generalized fabrication technology by means of force fields. Such a technology would be non-contact, flexible, and automated. The idea is based on the principle that waves carry momentum and energy with no mass transport. Scattering and gradient forces are generated from various types of wave motion. Starting from experiments on shaping walls using acoustic force fields, this thesis extends the technology to electromagnetic fields. The interaction physics of electromagnetic waves with dielectric material is studied. Electromagnetic forces on neutral dielectric material are shown to be analogous to acoustic forces on sound-scattering material. By analogy to the acoustic experiments, force fields obtained by optical tweezers are extended to longer wavelength electromagnetic waves while remaining in the Rayleigh scattering regime. Curing of the surface formed takes place by use of a higher frequency beam that scans the surface and melts a subsurface layer enabling a sintering effect to take place between the particles. The resulting capability is explored at its extremes in the context of building massive structures in Space. A unification of these areas is sought through a generalization of the various theories provided in the literature applicable for each field.
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Du, Plessis Anton. "A characterization of beam shaping devices and a tunable Raman laser." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/16313.

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Thesis (MSc)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: The efficient manipulation of various nonlinear optical processes frequently requires the shaping of the laser beams used for these processes. Three beam shaping techniques were investigated in this thesis. The focussing of Gaussian laser beams was investigated analytically, in order to efficiently manipulate the focussed beam characteristics. The beam-shaping characteristics of a diffractive optical element (DOE) was investigated numerically, which illustrates the beamshaping capability of the DOE, and identifies the critical parameters in experimental situations. The use of a waveguide as beam shaping device was investigated analytically and experimentally, and characterized for use with the available tunable laser sources. A Raman laser, or Raman shifter, employs stimulated vibrational Raman scattering to generate laser radiation at shifted frequencies. The waveguide was successfully applied as a beam shaping device in the Raman laser system, for optimisation of the process. The Raman laser system was investigated experimentally and characterized for use with the available tunable laser sources. The successful generation of laser radiation at shifted frequencies illustrates the usefulness of the system for generating tunable red-shifted frequencies. The results of this work allow the simple and efficient application of the Raman laser to generate laser radiation at shifted frequencies, in particular tunable infrared laser radiation which is desirable for molecular spectroscopy.
AFRIKAANSE OPSOMMING: Nie-liniêre optiese prosesse kan meer effektief benut word deur die vervorming van die laserbundels wat gebruik word in die prosesse. In hierdie tesis word drie laserbundel-vervormings tegnieke ondersoek. Die fokussering van Gaussiese laserbundels word analities ondersoek, om die gefokusseerde bundel se eienskappe effektief te manipuleer. Die bundel-vervormings eienskappe van ’n diffraktiewe optiese element word numeries ondersoek, wat die effektiwiteit van die bundelvervorming en die sensitiewe parameters in die sisteem uitwys. Die gebruik van ’n golfgeleier as ’n bundel-vervormings tegniek word ook analities en eksperimenteel ondersoek, en gekarakteriseer vir gebruik met die gegewe golflengte-verstelbare laser sisteme. ’n Raman laser, wat gestimuleerde vibrasionele Raman verstrooiing gebruik om laser lig te genereer by Stokes-verskuifde frekwensies, word ondersoek. Die golfgeleier word effektief gebruik as ’n bundel-vervormings tegniek in die Raman laser, om die bogenoemde nie-liniêre proses te optimeer. Die Raman laser was eksperimenteel ondersoek en gekarakteriseer vir gebruik met die gegewe golflengte-verstelbare lasers. Laser lig by verskuifde golflengtes is suksesvol gegenereer, wat die bruikbaarheid van die sisteem illustreer. Van belang is spesifiek verstelbare infrarooi laser lig, wat gebruik kan word in die laser-spektroskopie van molekules. Die resultate van hierdie werk lei tot die eenvoudige en effektiewe gebruik van die Raman laser, om langer golflengtes in die infrarooi gebied te genereer met ’n gegewe laser in die sigbare gebied.
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Cavallone, Marco. "Application of laser-plasma accelerated beams to high dose-rate radiation biology." Thesis, Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAX063.

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Le cancer est la deuxième cause de décès dans le monde, représentant environ un décès sur six en 2018. Parmi les techniques employées de nos jours dans la lutte contre le cancer, l’une des plus utilisées et prometteuses est la radiothérapie, technique consistant en l’utilisation de rayonnements ionisants afin de déposer de l’énergie dans la tumeur pour la traiter. Or, puisque les cellules saines sont également endommagées par les rayonnements, le but de la radiothérapie est d’augmenter la sélectivité du traitement en épargnant autant que possible les tissus sains. L’optimisation de la sélectivité repose sur plusieurs aspects, comprenant l’optimisation spatiale de la dose, la précision de l’imagerie et de la dosimétrie, le type de rayonnement et la structure temporelle utilisée pour délivrer la dose. En particulier, le rôle du débit de dose et du temps d’irradiation n’a pas encore été explorés en détail.Les accélérateurs cliniques délivrent la dose avec un débit de dose d’environ quelques Gy/min, ce qui entraîne des temps d’irradiation de l’ordre de quelques minutes. Si, d’une part, l’effet d’une réduction du débit de dose de l’ordre de cGy/min sur la réponse biologique est bien connu, d’autre part l’effet d’un débit de dose élevé doit encore être éclairci. Recemment, des études in vivo réalisées avec des électrons et des photons produits par des prototypes d’accélérateurs ont montré que l’administration de la dose dans un temps court (<500 ms) et à un débit de dose élevé (>40 Gy/s) augmente la sélectivité du traitement en réduisant le risque d’effets secondaires sur les tissus sains. Bien que les causes de ce phénomène soient encore à l’étude, le protocole FLASH a été testé avec succès sur le premier patient en 2019. Ces résultats soulignent l’importance de la structure temporelle de l’irradiation et les avantages potentiels que les protocoles d’irradiation à haut débit de dose peuvent apporter en clinique. Or, l’utilisation de ces protocoles demande une compréhension plus approfondie des processus physico-chimiques et biologiques déclenchés par un dépôt de dose rapide.Dans ce contexte, les faisceaux de particules accélérées par laser représentent un outil unique pour jeter de la lumière sur les processus qui régissent la réponse biologique suite à une irradiation à haut débit de dose. Ces faisceaux sont produits en focalisant une impulsion laser ultra-courte (~fs) et ultra-intense (1019 W/cm2) sur une cible mince solide ou gazeuse (~μm), ce qui produit des faisceaux de particules ayant une durée de l’impulsion allant de la picoseconde à la femtoseconde. Ces caractéristiques permettent d’atteindre un débit de dose dans l’impulsion de l’ordre de ~109 Gy/s, c’est-à-dire des conditions d’irradiation extrêmement différentes par rapport aux protocoles de traitement conventionnels et FLASH. Pour cette raison, les faisceaux de particules accélérées par laser ont reçu une grande attention au cours des dernières années, mais leur effet biologique est toujours en discussion et d’autres études plus approfondies sont nécessaires.Cette thèse décrit les atouts des Protons Accélérés par Laser (PAL) et des Électrons Accélérés par Laser (EAL) produits par différents types de laser à haute puissance disponibles dans le commerce. En particulier, elle présente des études expérimentales et théoriques réalisées avec trois types de faisceaux permettant différentes modalités temporelles d’administration de la dose. L’objectif est de traiter certains des principaux problèmes liés à l’application de ces sources de particules à la biologie des rayonnements et de montrer des solutions et des techniques viable pour mener des études de radiobiologie systématique. Cela demande une caractérisation précise de ces faisceaux, l’optimisation de la distribution de la dose dans la cible biologique à travers la conception de lignes de transport adaptées et, enfin, l’étude de la réponse des instruments de dosimétrie utilisés en clinique à haut débit de dose
Cancer is the second leading cause of death globally, accounting for an estimated 9.6 million deaths, or one in six deaths, in 2018. Besides surgery and chemotherapy, radiotherapy is one of the major treatment modality. It consists in the use of ionising radiation to kill cancerous cells by depositing energy into the tumour and destroying the genetic material that controls how cells grow and divide. While both cancerous and healthy cells are damaged by radiation, the goal of radiotherapy is to increase the treatment selectivity by sparing as much as possible the healthy tissues. Optimisation of the selectivity reposes on several aspects, including spatial optimisation of the dose, precision of imaging techniques and dosimetry instruments, use of different radiations and temporal structures of dose delivery. In particular, the role of the dose-rate and the total irradiation time has not been extensively explored yet.Clinical accelerators typically deliver the dose with a dose rate around few Gy/min, leading to exposure times in the order of few minutes to deliver a therapeutic dose. While the effect of a reduction of the dose rate in the order of cGy/min is well known, the effect of high-dose rate, fast irradiation on living cells still need to be elucidated. Evidences of an effect of the high dose-rate on the biological response have been recently observed in many studies. In particular, in-vivo studies performed with electrons and photons produced by accelerator prototypes have shown that delivering the prescribed dose in a short exposure time (<500ms) and at a high dose-rate (>40Gy/s) increases the treatment selectivity by reducing the occurrence of secondary effects on healthy tissues compared to conventional treatments with the same total dose. Although theoretical explanations underpinning such phenomenon are still under discussion, the so-called FLASH protocol has been successfully tested with the first human patient in 2019, paving the way for further research in this domain. These important results point out the importance of the dose delivery modality on the treatment selectivity and the potential benefit that high dose-rate protocols may bring to clinics, asking for a deeper understanding of the physico-chemical and biological processes following fast dose deposition.In this scenario, Laser-Driven Particle (LDP) beams represent a unique tool to shed some light on the radiobiological response following high-dose rate irradiation. LDP sources are produced by focusing an ultra-short (~fs) and ultra-intense (1019 W/cm2) laser pulse on a solid or gaseous thin target (~μm), producing proton and electron bunches with duration of respectively a few picoseconds and a few femtoseconds. These characteristics allow the reach of extremely high peak dose-rate in the pulse of the order of ~109 Gy/s in comparison with conventional and FLASH treatment protocols. For this reason, LDP sources have been receiving great attention in the last decade, but their radiobiological effect is still debated and further systematic studies are required.This thesis discusses the potential of both Laser-Accelerated Protons (LAP) and Laser-Accelerated Electrons (LAE) produced by different types of commercially available high-power lasers systems. In particular, it presents experimental and theoretical studies carried out with three different types of LDP beams, i.e. Hz LAPs, single-shot LAPs and kHz LAEs, enabling different temporal modalities of dose delivery. The goal is to address some of the main issues related to the application of such sources to radiation biology and show viable solutions and irradiation protocols to perform systematic radiobiology studies. Such issues include accurate characterisation of the source, optimisation of the dose distribution at the biological target through the design of adapted transport beamlines and investigation of the behaviour of dosimetric instruments for high dose-rate dosimetry
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Kropáč, Ondřej. "Návrh tvarovacího systému pro laserový svazek." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219163.

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Diploma thesis deal with design of laser beam shaping system. The theoretical part presents basic information about the light spread lika the optical beams. There are also properties of optical and optoelectronic components that are used for shaping the laser beam. The next section provides basic molding methods, their principles and qualities. In the last, experimental, part is first introduced designed computer algorithm, which is then used to calculate the quality parameters shaped laser beams. Following, there are presented the results of measurements and calculations for some of these methods.
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De, Clercq Ludwig Erasmus. "Numerical modelling of the excitation of polyatomic molecules by femtosecond laser beams." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6522.

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Thesis (MSc)--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: The selective excitation of an arbitrary vibrational level of a polyatomic molecule, without passage through an intermediary electronic excited state is demonstrated. This was achieved by simulating the interaction of a shaped, femtosecond pulse with one vibrational mode of the molecule. The carrier frequency of the pulse is chosen near resonant to the ground-to- rst-excited vibrational transition of the mode, and the pulse shape is optimized via closed-loop feedback. The simulation concentrates on the rst few vibrationally excited states since the density of states is still low, thus ensuring that the inter-vibrational decoherence time is relatively long compared to the pulse length. While various molecules were investigated this study focuses onUF6 for which detailed spectroscopic data for the v3 vibrational mode is available in literature. A multilevel model was developed and can be adapted for any number of levels. The model reported here was limited to a vibrational quantum number of four. The spectroscopic data included anharmonic splitting as well as forbidden transitions. The effect of rotational levels was not included. A density matrix approach was followed because this will allow for the introduction of dephasing of the coherent excitation via thermalizing collisions with the reservoir, as well as inter-vibrational relaxation. The time evolution of the density matrix is given by the Von Neumann equations.
AFRIKAANSE OPSOMMING: Die selektiewe opwekking van 'n arbitrêre vibrasionele vlak van 'n poliatomies molekule sonder oorgang na 'n intermediëre elektroniese opgewekte toetstand word gedemonstreer. Dit was bereik deur die interaksie te simuleer van 'n gevormde, femtosekonde pulse met een vibrasionele mode van 'n molekule. Die draer frekwensie van die pulse is so gekies dat dit naby resonansie van die grond-tot-eerste-opgewekte vibrasionele oorgang van die mode is, die puls vorm word geoptimeer deur 'n geslote-lus terugvoer. Die simulasie konsentreer op die eerste paar vibrasionele opgewekte toestande, omdat die digtheid van toestande nog steeds laag is, dus verseker dit dat inter-vibrasionele de-koherensie tyd relatief lank is in vergelyking met die puls se lengte. Verskillende molekules was ondersoek vir die studie. Die fokus is op UF6 waarvoor gedetaileerde spektroskopiese data vir die v3 vibrasionele beskikbaar is in die literatuur. 'n Multivlak model was ontwikkel en kan aangepas word vir enige aantal van vlakke. Die model wat hier aangemeld is, is beperk tot die vibrasionele kwantum getal van vier. Die spektroskopiese data het anharmonies splitting so wel as nie toegelaatbare oorgange bevat. Die effek van rotasionele vlakke was nie in berekening geneem nie. 'n Digtheids matriks benadering was gevolg, omdat dit toelaat vir die dekoherensie. Die tyd evolusie van die digtheids matriks word gegee deur die Von Neumann vergelykings.
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Baretela, Michael J. "Increasing prompt response from impulse radiating antenna by aperture shaping." Thesis, Monterey California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/6094.

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In order to improve the prompt response from an impulse radiating antenna (IRA)number of studies have suggested controlling the spatial distribution of the aperture fields by changing the feed arm angle. Other work has suggested that proper shaping of the aperture can further enhance the radiated signal for a given feed structure. This paper shows how the radiated prompt response can be maximized for a given feed arm configuration by shaping the aperture to eliminate fields orientated in the wrong direction. The percent increase in the prompt radiated electric field for a 200 . IRA with a ideally shaped aperture compared to a standard circular aperture ranged from 0.42% to 39.94% depending on the input electrode angle. For the most common electrode angles of 45Ê» and 60Ê» the increases are 6.00% and 16.63% respectively.
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Gagnon, Nicolas. "Phase Shifting Surface (PSS) and Phase and Amplitude Shifting Surface (PASS) for Microwave Applications." Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19826.

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This thesis describes an electrically thin surface used for electromagnetic applications in the microwave regime. The surface is free-standing and its primary purpose is to modify the phase distribution, or the phase and amplitude distribution of electromagnetic fields propagating through it: it is called phase shifting surface (PSS) in the first case, and phase and amplitude shifting surface (PASS) in the second case. For practical applications, the surface typically comprises three or four layers of metallic patterns spaced by dielectric layers. The patterns of the metallic layers are designed to locally alter the phase (and amplitude in the case of the PASS) of an incoming wave to a prescribed set of desired values for the outgoing wave. The PSS/PASS takes advantage of the reactive coupling by closely spacing of the metallic layers, which results in a larger phase shift range while keeping the structure significantly thin. The PSS concept is used to design components such as gratings and lens antennas which are presented in this document. The components are designed for an operating frequency of 30 GHz. The PSS phase grating gives high diffraction efficiency, even higher than a dielectric phase grating. Several types of lens antennas are also presented, which show comparable performance to that of a conventional dielectric plano-hyperbolic lens antenna with similar parameters. The PASS concept is used in a beam shaping application in which a flat-topped beam antenna is designed. This work demonstrates the potential for realising thin, lightweight and low-cost antennas at Ka band, in particular for substituting higher-gain antenna technologies such as conventional dielectric shaped lens antennas.
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Books on the topic "Radiation shaping"

1

Stein, Kenneth Merritt. Effects of pulse shaping on Cerenkov radiation. 1986.

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Tersigni, Samuel H. Classical analyses of nonstatistical fragmentation rates in van der Waals complexes and the shaping of radiation pulses for enhanced product selectivity in chemical reactions. 1990.

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Increasing Prompt Response from Impulse Radiating Antenna by Aperture Shaping. Storming Media, 2002.

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Book chapters on the topic "Radiation shaping"

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Bruggmoser, G., N. Nanko, R. Saum, and A. Nilles-Schendera. "Field Shaping in IORT." In Frontiers of Radiation Therapy and Oncology, 71–75. Basel: KARGER, 1997. http://dx.doi.org/10.1159/000061148.

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Fraass, Benedick, Daniel McShan, and Marc Kessler. "Dose-Based Con formal Field Shaping using Automated Optimization." In The Use of Computers in Radiation Therapy, 32–34. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59758-9_12.

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Zweigle, J. "Dynamical Simulations of the Shaping of PNe including Radiation Effects." In Planetary Nebulae, 294. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5244-0_147.

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Wrona, Stanislaw, Krzysztof Mazur, Jaroslaw Rzepecki, Anna Chraponska, and Marek Pawelczyk. "A-Weighting for Acoustic Radiation Shaping of a Vibrating Plate." In Advances in Intelligent Systems and Computing, 171–83. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50936-1_15.

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Gasser, A., E. W. Kreutz, and K. Wissenbach. "Beam Guiding and Shaping for Surface Processing with Laser Radiation." In Laser/Optoelektronik in der Technik / Laser/Optoelectronics in Engineering, 472–77. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-48372-1_99.

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van Asselen, B., C. P. J. Raaijmakers, P. Hofman, and J. J. W. Lagendijk. "An improved technique for tangential breast irradiation applying MLC field shaping and inverse planning." In The Use of Computers in Radiation Therapy, 197–99. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59758-9_72.

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Hartmann, Jörg, Christoph Kottmeier, Christian Wamser, and Ernst Augstein. "Aircraft Measured Atmospheric Momentum, Heat and Radiation Fluxes Over Arctic Sea Ice." In The Polar Oceans and Their Role in Shaping the Global Environment, 443–54. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm085p0443.

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Stepanov, Andrei G., János Hebling, and Jürgen Kuhl. "Transient Grating Generation and Waveform Shaping of Free-Space Propagating, Picosecond, Narrow-Band THz Radiation." In Springer Series in Chemical Physics, 714–16. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-27213-5_217.

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de Hazan, Yoram, Maciek Wozniak, Judit Heinecke, Gregor Müller, Veronika Märkl, and Thomas Graule. "Shaping Radiation Curable Colloidal Dispersions - From Polymer/Ceramic Fibers and Microspheres to Gradient Porosity Ceramic Bulk Materials." In Advanced Processing and Manufacturing Technologies for Structural and Multifunctional Materials IV, 85–95. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470944066.ch8.

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Cofran, K. L., and G. S. Ibbott. "MICROWAVE FIELD SHAPING IN CLINICAL HYPERTHERMIA." In Radiation Research: A Twentieth-century Perspective, 194. Elsevier, 1991. http://dx.doi.org/10.1016/b978-0-12-168561-4.50714-9.

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Conference papers on the topic "Radiation shaping"

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Soskind, M., R. Soskind, and Y. G. Soskind. "Coherent radiation enhancement for laser beam shaping applications." In SPIE Optical Engineering + Applications, edited by Andrew Forbes and Todd E. Lizotte. SPIE, 2014. http://dx.doi.org/10.1117/12.2063031.

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Remez, Roei, Niv Shapira, Charles Roques-Carmes, Romain Tirole, Yi Yang, Yossi Lereah, Marin Soljačić, Ido Kaminer, and Ady Arie. "Spectral and spatial shaping of Smith-Purcell radiation." In CLEO: QELS_Fundamental Science. Washington, D.C.: OSA, 2018. http://dx.doi.org/10.1364/cleo_qels.2018.fw4h.3.

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Sobol, Emil N., Alexander P. Sviridov, Victor N. Bagratashvili, Alexander I. Omelchenko, Yuriy M. Ovchinnikov, Anatoliy B. Shekhter, S. Downes, Steven Howdle, Nicholas Jones, and J. Lowe. "Stress relaxation and cartilage shaping under laser radiation." In Photonics West '96, edited by Steven L. Jacques. SPIE, 1996. http://dx.doi.org/10.1117/12.239596.

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Volpp, Joerg, Vadim V. Laskin, Aleksei B. Ostrun, and Alexander V. Laskin. "Beam shaping of focused radiation of multimode lasers." In High-Power Laser Materials Processing: Applications, Diagnostics, and Systems VII, edited by Stefan Kaierle and Stefan W. Heinemann. SPIE, 2018. http://dx.doi.org/10.1117/12.2287980.

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Mappatao, Gerino P. "Radiation pattern shaping for FM broadcast-optimizing coverage." In 2010 IEEE Symposium on Industrial Electronics and Applications (ISIEA 2010). IEEE, 2010. http://dx.doi.org/10.1109/isiea.2010.5679465.

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Wong, Liang Jie, Nicholas Rivera, Chitraang Murdia, Thomas Christensen, John D. Joannopoulos, Marin Soljacic, and Ido Kaminer. "Quantum Electron Wave-Shaping for Coherent Enhancement of Radiation." In CLEO: QELS_Fundamental Science. Washington, D.C.: OSA, 2020. http://dx.doi.org/10.1364/cleo_qels.2020.ff1q.6.

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Skobelev, S. P. "On the radiation efficiency of a dense array antenna shaping a sector radiation pattern." In 2008 International Conference on Mathematical Methods in Electromagnetic Theory (MEET). IEEE, 2008. http://dx.doi.org/10.1109/mmet.2008.4580981.

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Kornaszewski, Andrzej, Roman Spesyvtsev, Mohammed Shahzad, Enrico Brunetti, Przemysław W. Wachulak, Tomasz Fok, Łukasz Węgrzyński, et al. "Plasma density shaping for attosecond electron bunch generation." In Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources, edited by Dino A. Jaroszynski and MinSup Hur. SPIE, 2019. http://dx.doi.org/10.1117/12.2522780.

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Zverev, D., I. Snigireva, S. Kuznetsov, V. Yunkin, and A. Snigirev. "Beam-shaping refractive optics for coherent x-ray sources." In SYNCHROTRON AND FREE ELECTRON LASER RADIATION: Generation and Application (SFR-2020). AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0031372.

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Gasser, Andres, Ernst-Wolfgang Kreutz, and Konrad Wissenbach. "Beam guiding and shaping for surface processing with laser radiation." In The Hague '90, 12-16 April, edited by Hans Opower. SPIE, 1990. http://dx.doi.org/10.1117/12.20559.

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Reports on the topic "Radiation shaping"

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Klett, Jr, and Karl K. An Analysis of the Far-Field Radiation Pattern of the Ultraviolet Light-Emitting Diode (LED) Engin LZ4-00UA00 Diode with and without Beam Shaping Optics. Fort Belvoir, VA: Defense Technical Information Center, September 2015. http://dx.doi.org/10.21236/ada622302.

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