RaySearch Americas Inc. (NY) has introduced a commercial Monte Carlo dose algorithm (RS-MC) for routine clinical use in proton spot scanning. In this report, we provide validation of against phantom measurements and simulations the GATE software package. We also compared performance RayStation analytical (RS-PBA) RS-MC algorithm. A beam model (G-MC) scanning gantry at our center was implemented The validated water used benchmarking RS-MC. Validation performed by measuring depth doses...

Journal Article Functional problems in orthodontic patients out of retention Get access Michael Janson, Janson Bergen, Norway Addresses for correspondence Dr Connolly Str. 4, D-8000 München 40 Search other works by this author on: Oxford Academic PubMed Google Scholar Asbjörn Hasund European Orthodontics, Volume 3, Issue 1981, Pages 173–179, https://doi.org/10.1093/ejo/3.3.173 Published: 01 August 1981

The use of scanned proton beams in external beam radiation therapy has seen a rapid development over the past decade. This technique places new demands on treatment planning, as compared to conventional photon-based therapy. In this article, several specific functions implemented planning system RayStation are presented. We will cover algorithms for energy layer and spot selection, basic optimization including handling weight limits, linear transfer (LET) distribution, robust special case 4D...

The diffusion of deuterium ${(}^{2}\mathrm{H})$ in B and Al doped $4H$ $6H$ silicon carbide (SiC) has been studied detail by secondary ion mass spectrometry. From ${}^{2}\mathrm{H}$ depth profiles, following trap limited with negligible complex dissociation, an effective capture radius for the formation ${}^{2}\mathrm{H}\ensuremath{-}\mathrm{B}$ complexes (at 460 \ifmmode^\circ\else\textdegree\fi{}C) is determined to ${R}^{\mathrm{HB}}=(21\ifmmode\pm\else\textpm\fi{}4)\AA{}.$ This value good...

The aim of this study is to validate the RayStation Monte Carlo (MC) dose algorithm using animal tissue neck phantoms and a water breast phantom.Three anthropomorphic were used in clinical setting test MC algorithm. We two real necks that cut workable shape while frozen then thawed before being CT scanned. Secondly, we made patient phantom prosthesis filled with placed on flat surface. Dose distributions measured MatriXX PT device.The doses compared exceptionally well calculated by...

Transmission electron microscopy was used to investigate B11, C12, N14, Al27, Si28, and Ar37 ion-implanted 4H-SiC epilayers subsequent defect formation after high temperature annealing. During the annealing process extrinsic dislocation loops of interstitial type are formed on SiC basal plane with a depth distribution roughly corresponding implanted ions. The investigation reveals that in samples where ions substituting for position silicon sublattice, generating an excess silicon, more...

Ion implantation of deuterium is performed to investigate the mobility and passivating effect hydrogen in epitaxial α-SiC (polytypes 4H 6H). To avoid excessive damage resulting trapping hydrogen, with low energy (600 eV 2H2+). The H2 depth profile analyzed by secondary ion mass spectrometry. Electrical properties are measured capacitance–voltage profiling admittance spectroscopy. In p-type SiC, diffuses on a μm scale even at room temperature effectively passivates acceptors. n-type...

To assess if apertures shall be mounted upstream or downstream of a range shifting block these field-shaping devices are combined with the pencil-beam scanning delivery technique (PBS). The lateral dose fall-off served as benchmark parameter. Both options realizing PBS-with-apertures were compared to uniform mode. We also evaluated difference regarding out-of-field caused by interactions protons in beam-shaping devices. potential benefit configuration over was estimated analytically. Guided...

4H-SiC wafers of orientations (0001) and (112̄0) were implanted with 60 keV Al− in different major axial, planar, low symmetry (“random”) directions to ascertain the degree channeling determine optimum tilt conditions for ion implantation. Significant was observed all axial [112̄0] channel exhibiting deepest a maximum penetration depth 45 times greater than projected range random implants. {112̄0} especially {0001} planar channels while implants {101̄0} did not differ from corresponding To...

Experimental evidence is given for transient enhanced diffusion of boron (B) in ion-implanted silicon carbide (SiC). The implanted B diffusing several μm into the samples when annealed at 1600 and 1700 °C 10 min, but in-diffused tails remain unaffected annealing times are increased to 30 min same temperatures. A lower limit effective diffusivity determined 7×10−12 cm2/s, which 160 larger than equilibrium literature.

Heavily Al-doped 4H–SiC structures have been prepared by vapor phase epitaxy. Subsequent anneals carried out in an Ar atmosphere a rf-heated furnace between 1500 °C and 2000 for 0.5 to 3 h. Secondary ion mass spectrometry has utilized obtain Al concentration versus depth as well lateral distributions (ion images). Transmission electron microscopy (TEM) employed study the crystallinity determine composition after heat treatment. A solubility limit of ∼2×1020 Al/cm3 (1900 °C) is extracted....

The first to fourth order distribution moments, Rp, ΔRp, γ, and β, of 152 single energy H1, H2, Li7, B11, N14, O16, Al27, P31, Ga69, As75 implantations into silicon carbide (SiC) have been assembled. Fifty these performed analyzed in the present study while remaining implantation data was compiled from literature. For ions with a limited amount experimental data, additional were simulated using recently developed binary collision approximation code for crystalline materials. Least squares...

Some clinical indications require small fields with sharp lateral dose gradients, which is technically challenging in proton beam therapy. This holds especially true for low-range applied the spot scanning technique, where large profiles entering from beam-line or insertion of range shifting blocks lead to gradients. We regard latter case and solve it by block far upstream conjunction a collimating aperture close patient. The experiments current work are based on commercial therapy treatment...

To evaluate the impact of beam quality in terms distal fall-off (DFO, 90%-10%) and lateral penumbra (LP, 80%-20%) single ocular proton therapy (OPT) to derive resulting ideal requirements for future systems.Nine different models with DFO varying between 1 4 mm LP were created. Beam incorporated into RayStation RayOcular treatment planning system version 10 B (RaySearch Laboratories, Stockholm, Sweden). Each model was applied eight typical clinical cases, covering sizes locations uveal...

Vacancy-type defect production in Al- and Si-implanted 4H–SiC has been studied as a function of ion fluence, flux, implantation temperature the projected range region by positron annihilation spectroscopy Rutherford backscattering techniques. Ion channeling measurements show that concentration displaced silicon atoms increases rapidly with increasing fluence. In fluence interval 1013–1014cm−2 parameters are roughly constant at level tentatively associated divacancy VCVSi. Above 1014cm−2...

Alterations in the electronic structure of adsorbed zinc(II) etioporphyrin I (ZnEtio) through interaction with bridging oxygen vacancies on TiO(2)(110) are studied by scanning tunneling microscopy and spectroscopy at cryogenic temperatures under ultrahigh vacuum (UHV) conditions. Upon lateral manipulation ZnEtio molecules above surface vacancies, highest occupied molecular orbital shifts away from Fermi level. The magnitude shift rapidly decreases increasing distance molecule vacancy,...

Our purposes are to compare the accuracy of RaySearch's analytical pencil beam (APB) and Monte Carlo (MC) algorithms for clinical proton therapy present validation data using a novel animal tissue lung phantom.We constructed realistic phantom composed rack lamb resting on stack rectangular natural cork slabs simulating tissue. The tumor was simulated 70% lean ground meat inserted in spherical hole with diameter 40 ± 5 mm carved into slabs. A single-field plan an anterior two-field two...

Until today, the majority of ocular proton treatments worldwide were planned with EYEPLAN treatment planning system (TPS). Recently, commercial, computed tomography (CT)-based TPS for therapy RayOcular was released, which follows general concepts model-based approach in conjunction a pencil-beam-type dose algorithm (PBA).To validate respect to two main features: accurate geometrical representation eye model and accuracy its calculation combination an Ion Beam Applications (IBA) delivery...

A brief survey is given of some recent results on doping 4H- and 6H-SiC by ion implantation. The doses energies used are between 10(9) 10(15) cm(-2) 100 keV 5 MeV, respectively, ...