A5079535426- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Radiation Detection and Scintillator Technologies
- Acoustic Wave Resonator Technologies
- Mechanical and Optical Resonators
- Ultrasonics and Acoustic Wave Propagation
- Radiation Effects in Electronics
- Graphite, nuclear technology, radiation studies
- Thermography and Photoacoustic Techniques
- Nuclear Physics and Applications
- Particle accelerators and beam dynamics
- Photoacoustic and Ultrasonic Imaging
- Force Microscopy Techniques and Applications
- Advanced Chemical Physics Studies
- Metal Alloys Wear and Properties
- Thermal properties of materials
- Nuclear and radioactivity studies
- Advanced Fiber Laser Technologies
- Catalytic Processes in Materials Science
- Systemic Sclerosis and Related Diseases
- Shape Memory Alloy Transformations
- nanoparticles nucleation surface interactions
- Aerodynamics and Acoustics in Jet Flows
- Real-Time Systems Scheduling
- Powder Metallurgy Techniques and Materials
Paul Scherrer Institute
2009-2024
SpaceTech (Germany)
2023
Université de Strasbourg
2018
University of Konstanz
2012-2017
University of Nottingham
2015
Bariloche Atomic Centre
2012
Balseiro Institute
2012
Consejo Nacional de Investigaciones Científicas y Técnicas
2012
Institut des Molécules et Matériaux du Mans
2012
Centre National de la Recherche Scientifique
2012
In this paper we present the pencil beam dose model used for treatment planning at PSI proton gantry, only system presently applying therapy with a scanning technique. The scope of is to give general overview on various components model, related measurements and practical parametrization results. physical estimates from first principles absolute normalized number incident protons. flux measured in practice by plane-parallel ionization chambers (ICs) protons via Faraday-cup measurements. It...
In this paper, we report on the clinical application of fully automated three-dimensional intensity modulated proton therapy, as applied to a 34-year-old patient presenting with thoracic chordoma. Due anatomically challenging position lesion, three-field technique was adopted in which fields incident through lungs and heart, well beams directed directly at spinal cord, could be avoided. A homogeneous target dose sparing cord achieved field patching computer optimization 3D fluence each...
Purpose: The purpose of this work was to provide a flexible platform for FLASH research with protons by adapting former clinical pencil beam scanning gantry irradiations ultrahigh dose rates. Methods: PSI Gantry 1 treated patients until December 2018. We optimized the beamline parameters transport 250 MeV extracted from COMET accelerator treatment room, maximizing transmission intensity sample. characterized monitor on ensure good control dose, delivered in spot-scanning mode. different...
Research on ultra-high dose rate (UHDR) radiation therapy has indicated its potential to spare normal tissue while maintaining equivalent tumor control compared conventional treatments. First clinical trials are underway. The randomized phase II/III FEATHER trial at the Paul Scherrer Institute in collaboration with University of Zurich Animal Hospital is one first curative domestic animal be attempted, and it designed provide a good example for human trials. However, lack standardized...
The beam monitoring equipments developed for the first PSI spot scanning proton therapy facility, Gantry 1, have been successfully used more than 10 years. purpose of this article is to summarize author's experience in technique dynamic scanning.The dose delivery and verification use two independent computer systems. In article, detector construction, electronic system, dosimetry, quality assurance results are described detail. flux monitor calibrated with a Faraday cup. position realized by...
Mass-selected, cluster anion beams of Mo100±2.5– and (MoO3)67±1.5– were prepared with a magnetron source soft-landed onto highly ordered pyrolytic graphite (HOPG) under UHV conditions. These two clusters selected because they possess essentially the same masses consequently could be low kinetic energies. The chemical composition deposited was analyzed using in situ Auger electron spectroscopy ex X-ray photoelectron spectroscopy, while their surface morphologies characterized scanning...
We quantitatively study interfacial adhesion in a two-layer membrane system consisting of Al and Si with femtosecond time-resolved laser spectroscopy. High-frequency acoustic pulses the sub-THz regime are utilized to characterize system. In order explain distinct features measured data, spring model for Al/Si interface is employed. show that dissipation this needs be included accurate modeling over broad frequency range. This approach yields constant , an phonon lifetime ps at 240 GHz...
Various types of surface acoustic waves are generated by femtosecond pulses on bulk silicon with aluminium stripe transducers. Rayleigh and leaky longitudinal wave modes detected in the time domain for various propagation distances. The identified measuring pitches comparing spectra finite element calculations. lifetimes determined quantitatively spatially separating pump probe beam, showing a significant difference both modes. We were able to excite measure frequencies up 90 GHz using 100...
Acoustic frequency combs are optically excited and detected in silicon membranes covered with thin aluminum layers by femtosecond pump-probe spectroscopy. The various consist of 11 up to 45 modes ranging from 10 500 GHz. Evaluating the different allows us quantify dynamic properties this two-layer system great precision. Deviations frequencies higher a linear relation can be quantitatively understood. time domain traces show clearly defined pulses which regular intervals after each roundtrip...
The directional waveguiding in a 2D phononic crystal is simulated based on the analysis of equifrequency contours. This approach utilized to investigate acoustic beam splitting defect-free nanostructure low GHz range. We find relaxed limitations regarding source parameters compared similar approaches sonic regime. Finally, we discuss possibility design an interferometer device at nanoscale frequencies.
We present the commissioning and quality assurance of our clinical protocol for respiratory gating in pencil beam scanning proton therapy cancer patients with moving targets. In a novel approach, optical tracking has been integrated workflow used to monitor motion from multiple surrogates, applied on patients' chest. The system was tested under variety experimental conditions, specific therapy, evaluate reaction time reproducibility dose delivery control. proved be precise application...
Skutterudites are considered as interesting material for thermoelectric applications. Filling foreign atoms into the cagelike structure of a ${\mathrm{CoSb}}_{3}$ skutterudite is beneficial to its properties by increasing phonon scattering while maintaining electrical conductivity. In this paper we demonstrate generation and detection coherent acoustic phonons in thin films partially filled ${\mathrm{Yb}}_{x}{\mathrm{Co}}_{4}{\mathrm{Sb}}_{12}$ skutterudites using femtosecond pump-probe...
The dynamics of acoustic vibrations in terahertz quantum cascade laser structures (THz-QCLs) is studied by means femtosecond pump-probe spectroscopy. phonon modes are characterized the folding dispersion into an effective reduced Brillouin zone. An accurate identification this allows sample structure and periodicity to be determined with high precision on order 0.1%. By temperature tuning energy electronic levels system performing wavelength dependent measurements, we able study impulsive...
In laser ultrasonics, ultrashort light pulses generate coherent acoustic of picosecond duration via multiple possible physical mechanisms, involving optoacoustic conversion processes. These wide-band GHz signals are optically detected at the sample surfaces by ultrafast time-delayed probe pulses. When in GaAS Brillouin scattering 400 nm wavelength, certain spectral components remain invisible. The theoretical analysis relates this observation to existence zeros transformation function...
Confined longitudinal coherent acoustic phonon modes are excited and detected in a sub-μm-thick free-standing cubic GaN membrane by femtosecond pump-probe spectroscopy. After fs laser excitation, Brillouin oscillation thickness with frequencies up to 100 GHz observed studied the time domain. We found an initial expansion of upon optical excitation at 400 nm. Our experimental results confirmed earlier existing theoretical predictions observations that hydrostatic deformation potential is positive.
Guided acoustic waves are generated in nanopatterned silicon membranes with aluminum gratings by optical excitation a femtosecond laser. The spatial modulation of the photoacoustic leads to Lamb wavelengths determined grating period. excited optically detected for different periods and at distances up several μm between pump probe spot. measured frequencies compared theoretical dispersion relation thin membranes. Compared surface bulk twice higher (197 GHz 100 nm grating) membrane equal periods.
Many applications of thin films necessitate detailed information about their thicknesses and sound velocities. Here, we study SiO2/LiNbO3 layer systems by picosecond photoacoustic metrology measure the velocities respective layers film thickness SiO2, which pose crucial for fabrication surface-acoustic-wave filters communication technology. Additionally, utilize birefringence accompanying change in detection sensitivity coherent acoustic phonons LiNbO3 to infer orientation interface.