A5041111781- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Advanced MRI Techniques and Applications
- Ion-surface interactions and analysis
- Medical Imaging Techniques and Applications
- Radiation Effects in Electronics
- Advanced Thermodynamics and Statistical Mechanics
- Physics of Superconductivity and Magnetism
- Boron Compounds in Chemistry
- Astronomy and Astrophysical Research
- Cardiac Imaging and Diagnostics
- Astro and Planetary Science
- Electron and X-Ray Spectroscopy Techniques
- Superconducting Materials and Applications
- Forensic Fingerprint Detection Methods
- Radiation Effects and Dosimetry
- Integrated Circuits and Semiconductor Failure Analysis
- Stellar, planetary, and galactic studies
- Diamond and Carbon-based Materials Research
- High-pressure geophysics and materials
OncoRay
2017-2025
Helmholtz-Zentrum Dresden-Rossendorf
2017-2025
University Hospital Carl Gustav Carus
2017-2025
Center for Advanced Systems Understanding
2025
TU Dresden
2017-2023
Max Planck Institute for Nuclear Physics
1982-1986
Cornell University
1976-1981
Brown University
1976
The normal-fluid viscosity of liquid $^{3}\mathrm{He}$-$B$ has been determined in the neighborhood superfluid transition using torsional-oscillator technique Andronikashvili. In pressure range from 11.90 to 19.64 bars and for reduced temperatures $t\ensuremath{\equiv}\frac{T}{{T}_{c}}>0.98$, $B$-phase may be described by $\frac{\ensuremath{\eta}}{{\ensuremath{\eta}}_{c}}=1\ensuremath{-}[A{(1\ensuremath{-}t)}^{\frac{1}{2}}\ensuremath{-}B(1\ensuremath{-}t)]$, where ${\ensuremath{\eta}}_{c}$ is...
The classic technique of Andronikashvili has been used to determine the superfluid density $A$ and $B$ phases $^{3}\mathrm{He}$. In anisotropic phase, texture fluid is controlled through interaction between boundary condition on $\stackrel{\ensuremath{\rightarrow}}{l}$ vector an externally applied magnetic field. Comparison measurements made for different textures clearly establish anistropy tensor $^{3}\mathrm{He}\ensuremath{-}A$.
The temperature variation of the superfluid density has been measured for $^{4}\mathrm{He}$ films adsorbed on porous Vycor glass. Films with transition temperatures ranging from 0.1 to 1.5 K were studied. Apart a small rounding order $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}{T}_{c}$, these follows power law near similar bulk helium.
In proton therapy, patients benefit from the precise deposition of dose in tumor volume due to interaction charged particles with matter. Currently, determination beam range patient's body during treatment is not a clinical standard. This lack causes broad safety margins around tumor, which limits potential therapy. To overcome this obstacle, different methods are under investigation aiming at verification real time irradiation. One approach prompt gamma-ray timing (PGT) method, where...
We have studied the superfluid density of thin $^{4}\mathrm{He}$ films absorbed in porous Vycor glass. At low temperatures we used a third-sound technique to examine Landau elementary excitations. observed phonons with ${T}^{2}$ temperature dependence and rotons 5-K energy gap. higher examined critical region. The follows power law similar that bulk an exponent at value. conclude these effects are due three-dimensional geometry substrate.
Uncertainty in computed tomography (CT)-based range prediction substantially impairs the accuracy of proton therapy. Direct determination stopping-power ratio (SPR) from dual-energy CT (DECT) has been proposed (DirectSPR), and initial validation studies phantoms biological tissues have proven a high accuracy. However, thorough patients not yet achieved by any means. Here, we present first systematic CT-based using prompt gamma imaging (PGI).A PGI slit camera system with improved positioning...
Online treatment verification during proton therapy delivery may detect deviations due to anatomical changes occurring along the course and trigger immediate intervention, if necessary. We investigated potential of partial plan adaptation in two-field prostate cancer treatments as a solution for online-adaptive (OAPT) after detection relevant first field delivery. In retrospective study, ten fractions from eight patients with prompt gamma imaging (PGI) detected deviations, which were...
The development of online-adaptive proton therapy (PT) is essential to overcome limitations encountered by day-to-day variations the patient's anatomy. Range verification could play an role in online feedback loop for detection treatment deviations such as anatomical changes. Here, we present results first systematic patient study regarding detectability changes a prompt-gamma imaging (PGI) slit-camera system.For 15 patients with prostate cancer, PGI measurements were performed during 105...
A clinical study regarding the potential of range verification in proton therapy (PT) by prompt gamma imaging (PGI) is carried out at our institution. Manual interpretation detected spot-wise shift information time-consuming, highly complex, and therefore not feasible a broad routine application.Here, we present an approach to automatically detect classify treatment deviations realistically simulated PGI data for head-and-neck cancer (HNC) treatments using convolutional neural networks...
The thermal expansion of superfluid $^{4}\mathrm{He}$ under the saturated vapor pressure has been measured in temperature range 0.1-0.62 K. was found by filling a superconducting resonant cavity with liquid and measuring frequency as function temperature. density related to dielectric constant through Clausius-Mossotti relation. Sensitivity changes fractional 4 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}9}$ achieved. thermal-expansion data were used obtain quantitative...
Abstract Objective . To compare in reproducible and equalized conditions the performance of two independent proton range verification systems based on prompt gamma-ray detectors from different therapy centers. Approach An anthropomorphic head phantom with calibrated stopping power, serving as ground truth, was irradiated comparable treatment plans, spot positions energies both facilities. Clinical beam current, tumor contour dose were used. The absolute measurement compared to expected value...
The density of liquid $^{4}\mathrm{He}$ has been measured along the melting curve in temperature range 0.1-0.82 K by observing change with resonant frequency a superconducting microwave cavity immersed liquid. Relative changes as small 4 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}9}$ could be resolved. From results entropy solid was obtained using Clausius-Clapeyron equation conjunction values for isobaric-thermal-expansion coefficient and calculated from other data. No evidence...
Purpose Prompt‐gamma imaging (PGI)‐based range verification has been successfully implemented in clinical proton therapy recently and its sensitivity to detect treatment deviations is currently investigated. The cause of can be multiple — for example, computed tomography (CT)‐based prediction, patient setup, anatomical changes. Hence, it would beneficial, if PGI‐based not only a deviation but also able directly identify most probable source. Here, we propose heuristically derived decision...
In-situ range verification of ion beams during dose delivery is a key for further improving the precision and reducing side effects radiotherapy with particle beams. The detection analysis emission point, time or energy prompt gamma rays can provide corresponding means. Prompt gamma-ray imaging (PGI) has already been used in patient treatments proton timing (PGT) technique promises at lower hardware expense simpler systems superseding heavy collimators. After proving principle, this now...