| 1. |
- Ferretti, Gabriele, 1963, et al.
(författare)
-
Beyond the Standard Model Physics at the HL-LHC and HE-LHC
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of the High Luminosity (HL) phase of the LHC, defined as 3 ab−1 of data taken at a centre-of-mass energy of 14 TeV, and of a possible future upgrade, the High Energy (HE) LHC, defined as 15 ab−1 of data at a centre-of-mass energy of 27 TeV. We consider a large variety of new physics models, both in a simplified model fashion and in a more model-dependent one. A long list of contributions from the theory and experimental (ATLAS, CMS, LHCb) communities have been collected and merged together to give a complete, wide, and consistent view of future prospects for BSM physics at the considered colliders. On top of the usual standard candles, such as supersymmetric simplified models and resonances, considered for the evaluation of future collider potentials, this report contains results on dark matter and dark sectors, long lived particles, leptoquarks, sterile neutrinos, axion-like particles, heavy scalars, vector-like quarks, and more. Particular attention is placed, especially in the study of the HL-LHC prospects, to the detector upgrades, the assessment of the future systematic uncertainties, and new experimental techniques. The general conclusion is that the HL-LHC, on top of allowing to extend the present LHC mass and coupling reach by 20−50% on most new physics scenarios, will also be able to constrain, and potentially discover, new physics that is presently unconstrained. Moreover, compared to the HL-LHC, the reach in most observables will generally more than double at the HE-LHC, which may represent a good candidate future facility for a final test of TeV-scale new physics.
|
|
| 2. |
- Dykin, Victor, 1985, et al.
(författare)
-
Development of a Reduced Order Model and its application to the Forsmark-1 Instability Event of 1996/1997
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report describes the development of a reduced order model (ROM) which is then used to analyze a specific instability event . The ROM consists of three sub-models: a neutron-kinetic (NK) model (describing neutron transport), a thermal hydraulic (TH) model (HT) (describing the coolant flow ) and a heat transfer model (describing heat transfer between the fuel and the coolant). All these three models are coupled to each other, using two feedback mechanisms: void fraction feedback and doppler feedback. Each of the sub-models is described by a set of reduced ordinary differential equations, derived from the corresponding time-space dependent partial differential equations by using different types of approximations and mathematical methods. The neutron kinetic model is derived from the two-group time-space-dependent diffusion equations with one effective group of delayed neutrons by using eigenmode expansion. In the NK model, only the effect of the first three modes, namely the fundamental the first and the second azimuthal modes are taken into account. The thermal hydraulic model is derived from the space-time dependent mass, momentum and enthalpy local conservation equations, using spatial quadratic approximation for both the enthalpy and the quality distributions, after applying the weighted residual procedure. The equations are written for the single and for the two phase regions, separately. For the sake of simplicity, in the latter case the HEM is used. The heat transfer model is derived from an energy balance equation written for one fuel rod with three radial regions. The reduction of the (HT) equations is performed by assuming a piece-wise quadratic approximation for the fuel pellet temperature and using a weighted residual procedure (WRP). In order to have proper representation of both azimuthal modes, a four heated channels model was constructed. The recirculation loop model was also introduced into the ROM. The coupling reactivity coefficients for both void fraction and fuel temperature were calculated explicitly, evaluating the cross section perturbations with the help of the SIMULATE-3 system code and the CORE SIM simulator. As an event of interest for the application of the ROM, the instability event that happened in 1996/1997 at the Swedish Power Plant Forsmark-1, was chosen. The ROM input data were adjusted in order to represent the proper operational conditions. As a reference for benchmarking the ROM, the system code output data were used. The time signal for each of the modes were then calculated and some considerations about their stability were made
|
|
| 3. |
- Hansson, Johan
(författare)
-
Quantivity?
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)
|
|
| 4. |
- Manzetti, Sergio, et al.
(författare)
-
Derivation of a Hamiltonian for formation of particles in a rotating system subjected to a homogeneous magnetic field
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Bose-einstein condensates have received wide attention in the last decades given their unique properties. In this study, we apply supersymmetry rules on an existing Hamiltonian and derive a new model which represents an inverse scattering problem with similarities to the circuit and the harmonic oscillator equations. The new Hamiltonian is analysed and its numerical solutions are presented. The results suggest that the SUSY Hamiltonian describes the formation of vortices in a homogeneous magnetic field in a rotating system.
|
|
| 5. |
- Manzetti, Sergio, et al.
(författare)
-
Formation of quantum vortices in a rotating sphere in an electromagnetic field
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vortexes in three dimensional systems are an emerging topic of study in the realm of quantum physics, particle physics and magnetism. In this study we describe a new Hamiltonian, and solve it numerically for the description of vortices in a spherical model subjected to an electromagnetic field. The numerical analysis shows also that supersymmetric Hamiltonian describes quantized orbitals for atomic systems with vorticity included, which is to our knowledge novel and also describes electricity as composed of quasi-symmetric vortex bundles. Further work on analytical solutions is under development. The 3D solutions of the Hamiltonian are relevant for nuclear physics, in the physics of elementary particles, in geophysics, and in the physics of stellar bodies.
|
|
| 6. |
- Manzetti, Sergio, et al.
(författare)
-
Modelling the formation of atmospheric vortices on planet earth using a supersymmetric operator
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Macrophysical phenomena, such as turbulence, vorticity are normally modelled using fluid-mechanical differential equations and geodesics systems. Other methods may also be of importance to the meteorology community, such as quantum physical operators. In this study we use a novel Hamiltonian and study the vortex formation in the atmosphere of planet Earth under the effects of the gravity density stratification and the electromagnetic field of the planet. The results propose that vorticity in the atmosphere (high and low pressure systems) is driven in major part by the interplay between the earths magnetic field and gravity density. The results show that the quantized behaviour of atmospheric vortices lies in their dominant occurrence on the northern and southern hemispheres. The use of quantum mechanical operators in modelling planetary vorticity reveals also that these vortices arise from the core of the planet and manifest in a most pronounced manner on the surface of the earth where gravity density is experiencing an abrupt phase change. Further research is made on combining this model with earths atmospheric parameters, such as ocean temperatures and circulation, terrestrial oscillation and the sun's magnetic field. The results are important for future developments of climate and weather prediction models.
|
|
| 7. |
- Manzetti, Sergio, et al.
(författare)
-
Quantum vorticity in a rotating magnetic field
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vortexes in superfluids are a critical part of quantum optics, quantum dynamics studies and quantum physics in general. The behavior of vortexes is modeled by models such as the Ginzburg-Landau formula, and other systems, where symmetry-breaking is an inevitable event upon vortex formation. In this paper, we present and study a supersymmetric Hamiltonian which allows formation of vortexes in a quantum hall system to occur from the boundaries, as in natural phenomena, without breaking the symmetry. We study the numerical solutions of the Hamiltonian under rotating magnetic field.
|
|
| 8. |
- Mattsson, Sören, et al.
(författare)
-
Long-time variations of radionuclides and metals in the marine environment of the Swedish west-coast studied using brown algae : (Fucus serratus and Fucus vesiculosus)
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The support from SSM has made it possible to continue collecting brown algaefrom the place on the Swedish west coast where regular collections began asearly as 1967. The support has also enabled more extensive analyses ofpreviously collected material than was possible before. This applies to bothsupplementary analyses of previously reported radionuclides and analysis ofnew ones. The project has also enabled a start of more comprehensive analysesof the overall results. This has provided better information about long-termprocesses and seasonal variations for different radionuclides in both toothedwrack (Fucus serratus) and bladderwrack (Fucus vesiculosus). What is new isthat the sample material has now also been used to analyse metals, both thosewith known toxic effects such as lead, cadmium and mercury, as well as thosethat are of interest in assessing transport routes for radionuclides generated innew radiation sources, such as gadolinium isotopes from the EuropeanSpallation Source (ESS).Regarding the long-term development of various radionuclides in the marineenvironment on the Swedish west coast, the studies show rapidly increasinglevels of iodine-129, decreasing levels of cesium-137, technetium-99 andplutonium-239+240. The carbon-14 analyses suggest a continued inflow of thisradionuclide from the North Sea. The study also shows that the brown algaecould be important for the monitoring of emissions of naturally occurringradioactive materials (NORM) from the offshore oil and gas industry bysystematically studying long-term and seasonal variations of the content ofradium-228 and in the future also radium- 226 and lead-210. Interesting andhitherto unexplained variations in the beryllium-7 content in Fucus have beenmade. The tritium content in Fucus and in seawater has been analysed in alimited number of samples from 2020. No levels beyond the expected normalambient level for tritium have been found.During the 10-year period 2011-2020, there was a doubling of the levels of leadand nickel and a 50% increase in the levels of cadmium and cobalt in Fucus. Formercury a 10-fold decrease is registered between 2011 and 2016 and then adoubling of the concentration between 2016 and 2020. The decreasing trend formercury probably indicates an effect of the gradual phasing out of mercury inSweden and other countries. However, some businesses and companies have anexemption for continued use. For gadolinium there is an increase with a factor ofaround 5 from 2011 to 2020, most likely explained by the increased use ofgadolinium-containing contrast agents in magnetic resonance imaging inhealthcare.
|
|
| 9. |
- Nagy, Lajos, 1991, et al.
(författare)
-
Computational Investigation and Experimental Verification of Multiplicity Counting from the Continuous Signals of Fission Chambers
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In a series of previous publications, we suggested an alternative method to the pulse-counting based multiplicity counting technique for the characterisation of special nuclear materialscollision number expansion. The new method uses the continuous signals of fission chambers, and the multiplicity rates, i.e. the singles, doubles and triples rates are extracted from the auto- and cross-covariances of one or more fission chambers. Until recently only the theory of the method was elaborated. The purpose of the work described in this report was to verify the method and investigate its performance and applicability through detailed simulations as well as with a dedicated experiment. Numerical simulations of the method were performed by a code specially developed for this study, and pilot measurements were performed at the critical assembly KUCA of the Institute for Integrated Radiation and Nuclear Science, Kyoto University (KURNS). This report gives an account of both the work performed and the results of the study.
|
|
| 10. |
- Pál, Lénárd, 1925, et al.
(författare)
-
Comments on the stochastic characteristics of fission chamber signals
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents a theoretical investigation of the stochastic properties of the signal series of ionisation chambers, in particular fission chambers. The signals of the detector are assumed to be generated by incoming particles correspondig to an inhomogeneous Poisson distribution. Each incoming particle generates a current pulse with constant shape and random amplitude, and thedetector signal consists of the time series of such current signal pulses incurring also a pile-up effect in the case of high intensity of the primary events. Exact relationships are derived for the higher order moments of the detector signal, which constitute a generalisation of the so-called higher order Campbelling techniques. The probability distribution of the number of time points when the signal exceeds a certain level is also derived.Assuming that the incoming particles form a homogeneous Poisson process, explicit expressions are given for the higher order moments of the signal and the number of levelcrossings in a given time interval for a few selected pulse shapes.
|
|
