A5081723401- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Advanced Surface Polishing Techniques
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Magnetic confinement fusion research
- Microwave Engineering and Waveguides
- Electron and X-Ray Spectroscopy Techniques
- Bluetooth and Wireless Communication Technologies
- Metal and Thin Film Mechanics
- Muon and positron interactions and applications
- Carbon Nanotubes in Composites
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Physics of Superconductivity and Magnetism
- Laser Design and Applications
- Corrosion Behavior and Inhibition
- Ionic liquids properties and applications
- Nuclear Physics and Applications
- Electrodeposition and Electroless Coatings
- Acoustic Wave Resonator Technologies
- Scientific Measurement and Uncertainty Evaluation
Joint Institute for Nuclear Research
2024
Helmholtz-Zentrum Berlin für Materialien und Energie
2018-2024
Universität Hamburg
2015-2022
Deutsches Elektronen-Synchrotron DESY
2018
Belarusian State University of Informatics and Radioelectronics
2012
Abstract The Nuclotron-based Ion Collider fAcility (NICA) is currently under construction at JINR, with the first beam tests of scheduled for second half 2025. NICA project aims to provide colliding beams studying heavy fully stripped ion collisions energies up 4.5 GeV/u. accelerator complex comprises several components: operational linac HILAC an energy 3.2 MeV/u, superconducting Booster synchrotron a maximum 600 Nuclotron capable accelerating gold ions 3.9 GeV/u, and two storage rings...
Abstract Vacuum thermal treatments (baking) are known to improve the superconducting properties of RF surface layer niobium cavities, and employed as a last processing step increase their efficiency determined by intrinsic quality factor Q$_0$. A specific method perform baking has been used. It consists in annealing an evacuated cavity with local heaters installed on its outer cryostat which ensures exterior vacuum protects from oxidation. Such set-up number advantages it does not require...
Abstract The structural and chemical composition of the surface layer (100–140 nm) niobium radiofrequency cavities operating at cryogenic temperature has enormous impact on their superconducting characteristics. During last years, treated with a new thermal processing recipe, so-called nitrogen infusion, have demonstrated an increased efficiency high accelerating gradients. role importance gas been topic many debates. In present work we employ variable-energy synchrotron x-ray photoelectron...
Analysis of the strategy for superconducting cavity material procurement and quality management is done on basis experience with production European x-ray free electron laser (EXFEL) facility. An adjustment specification to EXFEL requirements, material, control (QC), documentation, shipment producers have been worked out carried by DESY. A multistep process qualification suppliers included detailed testing, single- nine-cell fabrication, cryogenic radiofrequency tests. Production about 25...
Abstract In order to determine optimal parameters of vacuum thermal processing superconducting radiofrequency niobium cavities exhaustive information on the initial chemical state and its modification upon a heat treatment is required. present work composition surface ultra-high baking at 200 ∘ C–400 C similar ‘medium-temperature baking’ ‘furnace explored in-situ by synchrotron x-ray photoelectron spectroscopy (XPS). Our findings imply that below critical thickness <mml:math...
Abstract The electrodeposition of copper onto niobium using commercial acidic and alkaline electrolytes was tested. continuous dense polycrystalline films were successfully obtained in aqueous alkaline-type bath containing sulphate, sodium hydroxide gluconate. effect benzotriazole lauryl sulphate additives on the morphology crystal structure deposited investigated by optical scanning electron microscopy, X-ray diffraction. No oxides found grown films. Copper had moderate adhesion properties...
Abstract Two niobium elliptical 1.3 GHz superconducting radio frequency (SRF) electron photoinjector cavities were successfully recovered after mechanical inner surface damage. Both had deep imprints in the critical high electric field area around photoelectric cathode position. The lengthy repair procedure, which consists of inspection and defect characterization, polishing light chemical etching is described detail. In process, a new pressure rinsing (HPR) nozzle system optimized for...
Abstract A niobium prototype and two test unjacketed 325 MHz coaxial half-wave cavities with beta=0.21 were designed, fabricated, tested at low RF fields. Electromagnetic properties investigated using a vector network analyzer in the frequency domain an generator, directional couplers, power detectors time (both continuous wave pulse mode).&#xD;We analyzed compared response of low-beta cavity both normal superconducting states.&#xD;We studied relationship between resonator parameters...
Abstract A prototype of the 325-MHz niobium half-wave coaxial resonator ( $$\beta = 0.21$$ ) is developed, built, and tested at low microwave field amplitudes. Electromagnetic properties in superconducting state are investigated continuous wave regime damping using a highly stable radio-frequency (RF) generator power detectors. The experimental data on resonator’s response used to calculate its most important characteristics—the intrinsic Q value accelerating field. experimentally measured...
The presence of defects on the inner surface Nb superconducting RF structures might limit its final performance. For this reason, strict requirements are imposed during mechanical production cavities, specifically quality control components, to avoid or scratches. Nevertheless, some may remain also after can arise from following steps. Understanding evolution defect shine new insight origin and help in defining possible repair techniques. This paper reports topographical a sample polished...
We have demonstrated a possibility to perform successful moderate-temperature (mid-T) heat treatment of superconducting cavity directly in cryostat. This method significantly reduces the number operations required for Mid-T baking effect research. The data obtained indicate cryomodule, allowing full use real accelerator.
In the present work chemical composition of niobium surface upon 200-400 {\deg}C baking similar to "medium-temperature baking" and "furnace cavities is explored in-situ by synchrotron X-ray photoelectron spectroscopy (XPS). Our findings imply that below critical thickness $Nb_2O_5$ layer (about 1 nm) starts interact actively with impurities, such as carbon phosphorus. By studying kinetics native oxide reduction, activation energy rate-constant relation have been determined used for...
Centrifugal barrel polishing (CBP) is a simple and environmentally friendly method that can be applied for mechanical abrasion of the cavity interior in order to remove mechanically damaged surface after its production. The CBP recipes described literature, however, require performed many stages, long processing times nevertheless are unable provide good RF performance without additional chemical processing. Here, we report new results on characterization surfaces treated with typical...
The method of direct formation horizontally aligned CNT networks on top substrates by conventional thermal CVD with volatile catalyst is report. main feature the proposed that temperature substrate kept at 100 - 150°C, while in reaction zone chamber 730 880°C. aforementioned realized growing CNTs and depositing onto two different zones reactor having temperatures these can be controlled independently. investigations scanning transmission electron microscopy conjunction Raman spectroscopy...
Abstract The general steps for the fabrication of a copper prototype 325 MHz coaxial half-wave resonator (HWR) with β = 0.21 are presented and discussed in this work. main features control electromagnetic properties during manufacturing process HWR described detail. resonant frequency sensitivity to accelerating gap cavity height were experimentally estimated. Bead-pull measurements performed electric field distribution along beam axis manufactured was cavity’s response critical coupling...