J. Bortfeldt
A5108167134- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Neutrino Physics Research
- Plasma Diagnostics and Applications
- Photocathodes and Microchannel Plates
- Radiation Therapy and Dosimetry
- Nuclear Physics and Applications
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- CCD and CMOS Imaging Sensors
- Atomic and Subatomic Physics Research
- Muon and positron interactions and applications
- Advanced Radiotherapy Techniques
- Distributed and Parallel Computing Systems
- Gas Sensing Nanomaterials and Sensors
- Nuclear reactor physics and engineering
- Gas Dynamics and Kinetic Theory
- Electron and X-Ray Spectroscopy Techniques
Ludwig-Maximilians-Universität München
2016-2025
Maxim Integrated (Germany)
2024
Institut für Urheber- und Medienrecht
2024
GSI Helmholtz Centre for Heavy Ion Research
2024
Munich University of Applied Sciences
2024
European Organization for Nuclear Research
2016-2023
MSB Medical School Berlin
2023
The University of Adelaide
2013-2020
Lancaster University
2019-2020
Northern Illinois University
2016-2020
The prospect of pileup induced backgrounds at the High Luminosity LHC (HL-LHC) has stimulated intense interest in developing technologies for charged particle detection with accurate timing high rates. required accuracy follows directly from nominal interaction distribution within a bunch crossing ($\sigma_z\sim5$ cm, $\sigma_t\sim170$ ps). A time resolution order 20-30 ps would lead to significant reduction these backgrounds. With this goal, we present new concept called PICOSEC, which is...
Abstract The PICOSEC Micromegas (MM) detector is a precise timing gaseous based on MM operating in two-stage amplification mode and Cherenkov radiator. Prototypes equipped with cesium iodide (CsI) photocathodes have shown promising time resolutions as 24 picoseconds (ps) for Minimum Ionizing Particles. However, due to the high hygroscopicity susceptibility ion bombardment of CsI photocathodes, alternative photocathode materials are needed improve robustness MM. Diamond-like Carbon (DLC) film...
Abstract Orthotopic tumor models in pre-clinical translational research are becoming increasingly popular, raising the demands on accurate localization prior to irradiation. This task remains challenging both X-ray and proton computed tomography (xCT pCT, respectively), due limited contrast of tissue compared surrounding tissue. We investigate feasibility gadolinium oxide nanoparticles as multimodal enhancement agent for imaging modalities.
We performed radiographies at experimental...
Abstract PICOSEC Micromegas (MM) is a precise timing gaseous detector based on Cherenkov radiator coupled with semi-transparent photocathode and an MM amplifying structure. The concept was successfully demonstrated through single-channel prototype, achieving sub-25 ps time resolution Minimum Ionizing Particles (MIPs). A series of studies followed, aimed at developing robust, large-area, scalable detectors high resolution, complemented by specialized fast-response readout electronics. This...
Abstract The PICOSEC Micromegas (MM) detector is a precise timing gaseous consisting of Cherenkov radiator combined with photocathode and MM amplifying structure. A 100-channel prototype 10 × cm 2 active area equipped Cesium Iodide (CsI) demonstrated time resolution below σ = 18 ps. objective this work to improve the robustness aspects, i.e. integration resistive carbon-based photocathodes, while maintaining good resolution. prototypes have been tested in laboratory conditions successfully...
Background: Precision small animal radiotherapy research is a young emerging field aiming to provide new experimental insights into tumor and normal tissue models in different microenvironments, unravel complex mechanisms of radiation damage target non-target tissues assess efficacy novel therapeutic strategies. For photon therapy, modern platforms have been developed over the last years are meanwhile commercially available. Conversely, for proton which holds potential an even superior...
Compton camera prototype for a position-sensitive detection of prompt <i>γ<i/> rays from proton-induced nuclear reactions is being developed in Garching. The detector system allows to track the Comptonscattered electrons. consists monolithic LaBr<sub>3<sub/>:Ce scintillation absorber crystal, read out by multi-anode PMT, preceded stacked array 6 double-sided silicon strip detectors acting as scatterers. crystal has been characterized with radioactive sources. Online commissioning...
The spatial dependence of the timing performance R3809U-50 Micro-Channel-Plate PMT (MCP-PMT) by Hamamatsu was studied in high energy muon beams. Particle position information is provided a GEM tracker telescope, while measured relative to second MCP-PMT, identical construction. In inner part circular active area (radius r<5.5 mm) time resolution two MCP-PMTs combined better than 10 ps. signal amplitude decreases outer region due less light reaching photocathode, resulting worse resolution....
Proton computed tomography (pCT) promises to reduce or even eliminate range uncertainties inherent in the conversion of Hounsfield units into relative stopping power (RSP) for proton therapy treatment planning. This is particular interest irradiation studies animal models due high precision required and tissue properties.
A novel irradiation platform for preclinical proton therapy studies foresees imaging accurate setup and treatment planning. Imaging at modern synchrocyclotron-based centers with high instantaneous particle flux is possible an integration mode setup. The aim of this work to determine object’s water-equivalent thickness (WET) a commercially available large-area CMOS sensor. Image contrast achieved by recording the energy deposition in detector pixels several incoming beam energies (here,...
The integration of the VMM3a Application-Specific Integrated Circuit (ASIC) into RD51's Scalable Readout System (SRS) provides a versatile tool for readout Micro-Pattern Gaseous Detectors (MPGDs). With its self-triggered high-rate readout, analogue part that allows to get information on deposited energy in detector, and so-called neighbouring-logic recover charge distribution, this new system has features particular interest digital X-ray imaging. In present article, we want emphasise...
Abstract The RD51 collaboration developed the Scalable Readout System (SRS) as part of its R&D activities on Micro-Pattern Gaseous Detectors. This common multi-purpose readout system allows to read out small detectors (0.2k channels) up mid-sized experiments with multiple (2.5k 5k channels). To cope increased demands detectors, electronics and speed, a new front-end ASIC—the VMM3a—was integrated into SRS. led development scalable, self-triggered high-rate that provides energy, space time...
Abstract The RD51 collaboration maintains a common infrastructure at CERN for its R & D activities, including two beam telescopes test campaigns. Recently, one of the has been equipped and commissioned with new multi-channel charge-sensitive front-end electronics based on ATLAS/BNL VMM3a ASIC Scalable Readout System (SRS). This allows to read out detectors high rates (up MHz regime) time resolutions order 1 ns ability handle different detector types sizes, due larger dynamic range...
Abstract The PICOSEC Micromegas precise timing detector is based on a Cherenkov radiator coupled to photocathode operating in semi-transparent mode and amplification structure. first proof of concept single-channel prototype was able achieve time resolution below 25 ps. One the crucial aspects development gaseous detectors applicable high-energy physics experiments modular design that enables large area coverage. 19-channel multi-pad with an active approximately 10 cm 2 suffered from...
Purpose: Development of a photon detection system designed for online range verification laser‐accelerated proton beams via prompt‐gamma imaging nuclear reactions. Methods: We develop Compton camera the position‐sensitive prompt photons emitted from reactions between beam and biological samples. The detector is to be capable reconstruct source origin not only scattering kinematics primary photon, but also allow tracking Compton‐scattered electrons. Results: Simulation studies resulted in...
Objective.Image guidance and precise irradiation are fundamental to ensure the reliability of small animal oncology studies. Accurate positioning in-beam monitoring delivered radio-therapeutic treatment necessitate several imaging modalities. In particular context proton therapy with a pulsed beam, information on dose can be retrieved by thermoacoustic waves resulting from brief local energy deposition induced beam (ionoacoustics). The objective this work was fabricate multimodal phantom...
Detectors with a time resolution of few tens picoseconds and long-term durability in high particle fluxes are necessary for an accurate vertex separation future physics experiments. The PICOSEC-Micromegas detector concept is Micro-Pattern Gaseous Detector (MPGD) based solution addressing this particular challenge. It on Micromegas coupled to Cherenkov radiator photocathode. Primary electrons from the incident particles generated photocathode fluctuations due different primary ionisation...
Abstract Detectors with a time resolution of 20-30 ps and reliable performance in high particles flux environments are necessary for an accurate vertex separation future HEP experiments. The PICOSEC-Micromegas detector concept is Micro-Pattern Gaseous Detector (MPGD) based solution addressing this particular challenge. on Micromegas coupled to Cherenkov radiator photocathode. In concept, all primary electrons initiated the photocathode jitter fluctuations reduced. Different resistive anode...