A5045049224- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Radiation Therapy and Dosimetry
- Crystallography and Radiation Phenomena
- Radiation Detection and Scintillator Technologies
- Atomic and Molecular Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Ion-surface interactions and analysis
- Superconducting Materials and Applications
- Advanced Electron Microscopy Techniques and Applications
- Graphite, nuclear technology, radiation studies
- Muon and positron interactions and applications
- Astrophysics and Cosmic Phenomena
- Laser-Plasma Interactions and Diagnostics
- Radioactive contamination and transfer
- Astro and Planetary Science
- Biofield Effects and Biophysics
- Nuclear and radioactivity studies
- Semiconductor Lasers and Optical Devices
- Plasma Diagnostics and Applications
- Photonic and Optical Devices
- Optical Network Technologies
Aarhus University
2008-2023
European Spallation Source
2014
The total cross sections for single ionization of helium and double argon by antiproton impact have been measured in the kinetic energy range from 3 to 25 keV using a new technique creation intense slow beams. data provide benchmark results development advanced descriptions atomic collisions we show that they can be used judge, first time, validity many recent theories.
The classical description of synchrotron radiation fails at large Lorentz factors, $\gamma$, for relativistic electrons crossing strong transverse magnetic fields $B$. In the rest frame electron this field is comparable to so-called critical $B_0 = 4.414\cdot10^9$ T. For $\chi \gamma B/B_0 \simeq 1$ quantum corrections are essential conserve energy. With energies 10-150 GeV penetrating a germanium single crystal along $<110>$ axis, we have experimentally investigated transition from regime...
Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing CCD detector are presented. It is shown that pairs--when detected close to creation vertex--suffer reduced due internal screening charges constituting pair. Furthermore, ability measure directly pair by calorimetry enables comparison with theory as function energy. The observed phenomenon good qualitative agreement general expectations Chudakov effect but...
The European Spallation Source, ESS, uses a linear accelerator to bombard the tungsten target with high intensity protons beam for producing intense beams of neutrons. nominal average power linac is 5 MW peak at 125 MW. During last year ESS cost was re-evaluated, and meet budget few modifications were introduced design. One major changes reduction final energy from 2.5 GeV 2.0 therefore current increased accordingly compensate lower energy. As result designed objective by taking higher risk....
Experimental results for the radiation emission from ultrarelativistic electrons in targets of 0.03%--5% length is presented. For thinnest targets, accordance with Bethe-Heitler formulation bremsstrahlung, target acting as a single scatterer. In this regime, intensity proportional to thickness. As thickness increases, distorted Coulomb field electron that result first scattering events, leads suppressed per interaction, upon subsequent events. case, becomes logarithmic function thickness,...
The residual activity induced in particle accelerators is a serious issue from the point of view radiation safety as long-lived radionuclides produced by fast or moderated neutrons and impact protons cause problems exposure for staff involved maintenance work when decommissioning facility. This paper presents activation studies magnets collimators High Energy Beam Transport line European Spallation Source due to backscattered target also direct proton interactions their secondaries. An...
Experimental results for the radiative energy loss of 206 and 234 GeV electrons in 5–10 μm thin Ta targets are presented. An increase radiation emission probability at low photon energies compared to a 100 thick target is observed. This due formation length photons exceeding thickness foils, so-called Ternovskii–Shul'ga–Fomin (TSF) effect. The from multi-hundred projectile through TSF effect shown directly be factor 1010 longer than their wavelength.
We show by experiment that an electron impinging on electric field is of critical magnitude in its rest frame, may produce electron-positron pair. Our measurements address higher-order QED, using the strong fields obtainable along particular crystallographic directions single crystals. For amorphous material our data are good agreement with theory, whereas a discrepancy theory trident enhancement found precisely aligned case where acts.
When an ultrarelativistic electron traverses two closely spaced foils, a radiation spectrum 'resonance' appears, arising from the photon formation length extending one foil, across gap and into second foil. Several theoretical approaches yield quite different answers to spectral location of this 'resonance', we have therefore in CERN NA63 collaboration addressed question experimentally with 178 GeV beam. The experimental technique used – where variable separates thin gold foils allows for...
The accelerator of the European Spallation Source (ESS) will deliver 62.5 mA proton beam 2.0 GeV onto target, offering an unprecedented power 5 MW. Since the technical design report (TDR) was published in 2013, work has continued to further optimise design. We report on advancements lattice optimisations after TDR improve performance and flexibility, and reduce cost ESS
Following an optimization of the European Spallation Source (ESS) linac, a number changes have been introduced in High Energy Beam Transport (HEBT). In particular, about 120 m beam transport has allocated to enable extension superconducting thus providing some contingency against poor linac performance and potentially allowing future power upgrade. The layout optics all HEBT lines will be discussed.
A 30° Green Magnet based on permanent NdFeB magnets has been developed and installed in the injection line at ASTRID2 synchrotron light source. The cost efficient design is optimized for a 1 T field length of m using shaped iron poles to surpass required homogeneity. inherent temperature dependence passively compensated below 30 ppm/°C. study potential demagnetization effects performed by irradiation samples placed directly 100 MeV e-beam. high magnet work point was found result enhanced...