Review of Charged Particle Dynamics. Beam Optics and Focusing Systems Without Space Charge. Linear Beam Optics with Space Charge. Self-Consistent Theory of Beams. Emittance Variation. Beam Physics Research from 1993 to 2007. Appendices. List of Frequently Used Symbols. Bibliography. Index.

Theory and Design of Charged Particle Beams

Foundations For Microwave Engineering

The mechanism by which social media influencers persuade consumers: The role of consumers’ desire to mimic

Transmission-Line Theory By Prof. Ronald W. P. King. Pp. xii + 509. (London: McGraw-Hill Publishing Company, Ltd., 1955.) 90s.

/pdf/transmission-line-theory-5bm2m9rdr7.pdf

Transmission-Line Theory

Various in vivo experimental works carried out on different animals and organs have shown that it is possible to reduce the damage caused to healthy tissue still preserving the therapeutic efficacy on the tumor tissue, by drastically reducing the total time of dose delivery (<200 ms). This effect, called the FLASH effect, immediately attracted considerable attention within the radiotherapy community, due to the possibility of widening the therapeutic window and treating effectively tumors which appear radioresistant to conventional techniques. Despite the experimental evidence, the radiobiological mechanisms underlying the FLASH effect and the beam parameters contributing to its optimization are not yet fully known. In order to fully understand the FLASH effect, it might be worthy to investigate some alternatives which can further improve the tools adopted so far, both in terms of linac technology and dosimetric systems. This work investigates the problems and solutions concerning the realization of an electron accelerator dedicated to FLASH and optimized for in vivo experiments. Moreover, the work discusses the saturation problems of the most common radiotherapy dosimeters when used in the very high dose-per-pulse FLASH region and provides some preliminary experimental data on their behaviour.

/pdf/flash-radiotherapy-with-electrons-issues-related-to-the-3340gssse1.pdf

FLASH Radiotherapy With Electrons: Issues Related to the Production, Monitoring, and Dosimetric Characterization of the Beam

A broad-band transmission line spatial power combiner (SPC) is proposed in this paper, which uses a square coaxial (Squarax) transmission line (TL). This structure has some advantages over the traditional circular coaxial spatial power combiner, which have been described in this paper. Fin-Line to microstrip transitions are inserted into the Squarax TL, in order to allow an easy integration of Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifler (SSPA). The Squarax SPC geometry allows the feeding of a higher number of MMIC than in a Waveguide SPC, so that this structure ensures high power outputs and small sizes, together with theoretical DC frequency cut-ofi. In this work, the design and simulation of a passive 4{18GHz Squarax SPC are reported.

/pdf/the-squarax-spatial-power-combiner-9lfxv4xlu9.pdf

The squarax spatial power combiner

A Ka-Band, High Efficiency, Small Size Spatial Combiner (SPC) is proposed in this paper, which uses an innovatively matched quadruple Fin Lines to microstrip (FLuS) transitions. At the date of this paper and at the Author's best knowledge no such FLuS innovative transitions have been reported in literature before. These transitions are inserted into a WR28 waveguide T-junction, in order to allow the integration of 16 Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPA's). A computational electromagnetic model using the finite elements method has been implemented. A mean insertion loss of 2 dB is achieved with a return loss better the 10 dB in the 31-37 GHz bandwidth.

http://aemjournal.org/index.php/AEM/article/download/267/pdf_41

High Efficiency Ka-Band Spatial Combiner

Over the past decade, unmanned air vehicles are gaining more and more interest and popularity in particular miniaturized small flight objects named NAVs (Nano Air Vehicles). One of the main considerations when building or buying a drone is the flight time and range. The flight time is nowadays a drawback for miniature unmanned aerial vehicles (UAVs). It is limited to few minutes before requiring a forced recovery to replace exhausted batteries. Currently the batteries are the dominant technology, which possess limited operation in time and energy. The real viability to extending flight time (FT) of NAVs is possible exploring new and more disruptive alternative solution able either to recharge a battery, or even to directly power the NAVs during the flight. Plasmonic Nano Energy harvester is an attractive technology to extending the FT extracting the energy in mid-infrared radiation emitted from Earth’s surface with Rectenna tuned to mid-infrared wavelengths (7 –14 ) um with a peak wavelength of about10um . In this review the concepts emerging from this work identify and suggest how this novel harvester can constantly supply these flying objects for the whole day.

https://metaconferences.org/aemjnew/index.php/AEM/article/download/462/pdf

Nano Energy Harvesting with Plasmonic Nano-Antennas: A review of MID-IR Rectenna and Application

This paper proposes a particular design technique of an 8 slots resonant cavities X-Band Magnetron. Such study is based on a Multiphysics (MP) simulation and consider thermal-structural effects due to the cathode heating, taking into account that electromagnetic behavior and thus device efficiency depend critically to the operating temperature and to the related thermal induced displacements of the materials. The proposed study involves Thermal Stress (TS), Eigen-frequency (EF) and Particle Tracing (PT) analysis performed with the Finite Element Method (FEM). These computations have been performed on COMSOL. Electric field related to the main resonant modes and particle trajectories have been computed in thermo mechanical operative conditions. Magnetron working points have been estimated.

Multiphysics Modeling Based Design of a Key-Holes Magnetron

This paper describes the design based on a Multiphysics simulation for a waveguide X-Band Fin Taper (FT) Spatial Power Combiner. The proposed device uses Fin Lines to microstrip transition (FLuS) to convert the energy from a rectangular waveguide (WG) TE10 fundamental mode to a microstrip (μS) transmission line (TL) quasi-TEM (q-TEM) mode, in order to be amplified by Solid-State Power Amplifiers. An alteration of the electromagnetic behavior can be produced by the temperature increase and the geometrical displacement induced by the thermal expansion of the structure due to the power dissipation of the MMIC amplifiers. A proper multiphysics model is proposed to select materials and shapes of the probes and their support (carrier), considering the thermo-mechanical operative condition. A virtual prototyping technique is proposed: electric field and S-parameters’ computation in such critical conditions are shown. The proposed study has allowed for the proper thermo-mechanical design for such amplifiers; henc...

A Leggieri

Papers

The squarax spatial power combiner

High Efficiency Ka-Band Spatial Combiner

Nano Energy Harvesting with Plasmonic Nano-Antennas: A review of MID-IR Rectenna and Application

Multiphysics Modeling Based Design of a Key-Holes Magnetron

Multiphysics design of a spatial combiner predisposed for thermo-mechanically affected operation