| 1. |
- Singh, B., et al.
(författare)
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Study of doubly strange systems using stored antiprotons
- 2016
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Ingår i: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
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Tidskriftsartikel (refereegranskat)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 2. |
- Collaboration, The PANDA, et al.
(författare)
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Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
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Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
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Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 3. |
- Singh, B., et al.
(författare)
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Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
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Tidskriftsartikel (refereegranskat)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 4. |
- Barucca, G., et al.
(författare)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Tidskriftsartikel (refereegranskat)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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| 5. |
- Akbarnejad, Shahin, et al.
(författare)
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An investigation on permeability of ceramic foam filters (CFF)
- 2015
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Ingår i: TMS Light Metals. - Hoboken, NJ, USA : Wiley. - 9781119082446 ; , s. 949-954, s. 949-954
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Konferensbidrag (refereegranskat)abstract
- CFFs are used to filter liquid metal in the aluminum industry. CFFs are classified in grades or pores per inch (PPI), ranging from 10-100 PPI. Their properties vary in everything from pore and strut size to window size. CFFs of 80-100 PPI are generally not practical for use by industry, as priming of the filters by gravitational forces requires an excessive metal head. Recently, co-authors have invented a method to prime such filters using electromagnetic Lorentz forces, thus allowing filters to be primed with a low metal head. In the continuation of this research work, an improved experimental setup was developed in the present study to validate previous results and to measure the permeability of different filters, as well as a stack of filters. The study of permeability facilitates estimation of the required pressure drop to prime the filters and the head required to generate a given casting rate.
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| 6. |
- Anders, S., et al.
(författare)
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European roadmap on superconductive electronics - Status and perspectives
- 2010
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Ingår i: Physica C: Superconductivity and its Applications. - : Elsevier BV. - 0921-4534. ; 470:23-24, s. 2079-2126
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Tidskriftsartikel (refereegranskat)abstract
- For four decades semiconductor electronics has followed Moore's law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has saturated at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technology that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range - dependent on the material - of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 mu W per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analogue-to-digital converters for commercial and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Phi(0). The flux quantum is also the natural quantization unit for digital-to-analogue and analogue-to-digital converters. The latter application is so precise, that it is being used as voltage standard and that the physical unit 'Volt' is defined by means of this standard. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geological surveying and food-processing and for non-destructive testing. As amplifiers of electrical signals. SQUIDs can nearly reach the theoretical limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by 'transition-edge' bolo-meters, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now standard. The very low losses of superconductors have led to commercial microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The number of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temperatures. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available commercially, from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temperature techniques in standard applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field: - Ultra-sensitive sensing and imaging. - Quantum measurement instrumentation. - Advanced analogue-to-digital converters. - Superconductive electronics technology.
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| 7. |
- Fritzsch, R., et al.
(författare)
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Effect of electromagnetic fields on the priming of high grade Ceramic Foam Filters (CFF) with liquid aluminum
- 2015
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Ingår i: TMS Light Metals. - Hoboken, NJ, USA : The Minerals, Metals, and Materials Society. - 9781119082446 ; , s. 929-935, s. 929-935
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Konferensbidrag (refereegranskat)abstract
- Electromagnetic fields can influence the behavior of liquid metals in commercial Ceramic Foam Filters (CFF's). In the present study 9 inch industrial CFF's of high grade with 50 and 80 pores per inch (ppi) have been investigated. The main objective was to prime the 9 inch industrial scale CFF's with a standard aluminum casting alloy (3XXX - alloy) by the use of various magnetic field strengths (max. 0.12 T) induced by a coil. The obtained results were compared with reference gravity experiments. The influence of the electromagnetic Lorentz forces on the obtained results was calculated with 2D Finite Element Modeling (FEM) using the COMSOL® software. The fluid flow characteristics inside the CFF were considered and are part of another publication within the group.
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| 8. |
- Fritzsch, R., et al.
(författare)
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A novel method for automated quantification of particles in solidified aluminium
- 2014
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Ingår i: TMS 2014 143rd Annual Meeting & Exhibition, Annual Meeting Supplemental Proceedings. - Hoboken, NJ, USA : The Minerals, Metals, and Materials Society. - 9781118889725 ; , s. 535-543
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Konferensbidrag (refereegranskat)abstract
- Particle concentration and size distribution in the melt can give important information regarding the filtration efficiency and the quality of the aluminium. LiMCA (Liquid Metal Cleanliness Analyser) system, used in primary and secondary production of aluminium, provides in-situ data for granulometric and total density information on the inclusion content, but has problems quantifying particles < 20 μm in size. To be able to determine the required cleanliness with particle counts down' to 10 μm for modern alloys a novel method for automated quantitative results has been developed. Results are obtained using a user friendly technique based on the ImagePro® Plus 7.0 software. The different image processing steps adopted for automated quantification of the particle count in a size range from 2 to 50 μm is described and discussed together with the obtained results. The automated technique has been benchmarked elsewhere with a manual particle count reviling an error of ∼3% on the overall filtration efficiency.
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| 9. |
- Fritzsch, R., et al.
(författare)
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Automated quantification of SiC-particles in solidified A356 aluminium using ImagePro® plus 7.0
- 2013
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Ingår i: TMS Annu Meet. - 9781118605646 ; , s. 69-77
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Konferensbidrag (refereegranskat)abstract
- The quantitative particle concentration can give important information about the cleanliness of melts for quality control in primary and secondary production of aluminum. Manual quantification of the particle concentration is normally a time consuming process and human control can bias the acquired images and particle count. The present paper explains the automated image-processing steps for the quantification of SiC-particles, with equivalent diameters from 2 to 25 μm, in solidified A356. A total of 700 micrographs, acquired with a standard white light microscope with 10 x magnification, were analyzed. The applied software (Image Pro-Plus 7.0 from MediaCybernetics®) allows for programming of macros which in turn provides the user with a higher degree of control. The automated results are compared with the results obtained by manually counting the particles in the same micrographs. The impact of the automated results on the estimated filtration efficiency was established to be only ∼3%.
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| 10. |
- Fritzsch, R., et al.
(författare)
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Electromagnetic priming of ceramic foam filters (CFF) for liquid aluminum filtration
- 2016
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Ingår i: 142nd Annual Meeting and Exhibition, TMS 2013. - Cham : Springer International Publishing. ; , s. 973-979
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Konferensbidrag (refereegranskat)abstract
- Commercial Ceramic Foam Filters (CFF) of 30, 50 and 80 Pores Per Inch (PPI) have been primed, using magnetic field strengths of 0.06–0.2T, for periods of 1–10 minutes. The influence of time and field strength on the gas removal from the CFF structure, and the resulting improvements in filter productivity, are discussed. The obtained results are related to Finite Element Modeling (FEM) of the metal flow fields induced by the electromagnetic Lorentz forces. Higher filtration rates were obtained for 50 PPI magnetically primed, than for 30 PPI gravity primed filters. This suggests that electromagnetic priming offers an opportunity to use 50 PPI filters, with a higher overall filtration efficiency than 30 PPI filters, in existing cast house applications where the low productivity/high priming head of these filters would otherwise rule them out. Estimated filtration efficiency of different filter types are presented as functions of velocity and thickness.
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| 11. |
- van Doremalen, Ric, et al.
(författare)
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Wireless activity monitor using 3D integration
- 2009
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Ingår i: Proceedings of Symposium on Design, Test, Integration and Package of MEMS/MOEMS (DTIP 2009), Rome, Italy.
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Konferensbidrag (refereegranskat)
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