Project of the underwater system for chemical threat detection

In this article we describe a novel method for the detection of explosives and other hazardous substances in the marine environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides forneutron and gamma quanta which speeds up and simplifies identification. Moreover, it may provide a determination of the density distribution of a dangerous substance. First preliminary results of Monte Carlo simulations dedicated for design of a device exploiting this method are also presented.Comment: 9 pages, 6 figure

Design of the SABAT system for underwater detection of dangerous substances

We present status of simulations used to design a novel device for the detection of hazardous substances in the aquatic environment using neutron activation. Unlike the other considered methods based on this technique we propose to use guides for neutron and gamma quanta which speeds up and simplifies identification. First preliminary results show that both the neutron guide and the $\gamma$ ray guide increase the performance of underwater threats detection.Comment: Presented at the Jagiellonian Symposium of Fundamental and Applied Subatomic Physics, Krak{\o}w, 11.06.201

Underwater detection of dangerous substances: status the SABAT project

The Neutron Activation Analysis (NAA) plays an exceptional role in the modern nuclear engineering, especially in detection of hazardous substances. However, in the aquatic environment, there are still many problems to be solved for effective usage of this technique. We present status of SABAT (Stoichiometry Analysis By Activation Techniques), one of the projects aiming at construction of an underwater device for non-invasive threat detection based on the NAA

Controlled exchange interaction for quantum logic operations with spin qubits in coupled quantum dots

A two-electron system confined in two coupled semiconductor quantum dots is investigated as a candidate for performing quantum logic operations on spin qubits. We study different processes of swapping the electron spins by controlled switching on/off the exchange interaction. The resulting spin swap corresponds to an elementary operation in quantum information processing. We perform a direct time evolution simulations of the time-dependent Schroedinger equation. Our results show that -- in order to obtain the full interchange of spins -- the exchange interaction should change smoothly in time. The presence of jumps and spikes in the corresponding time characteristics leads to a considerable increase of the spin swap time. We propose several mechanisms to modify the exchange interaction by changing the confinement potential profile and discuss their advantages and disadvantages

MesonNet Workshop on Meson Transition Form Factors

The mini-proceedings of the Workshop on Meson Transition Form Factors held in Cracow from May 29th to 30th, 2012 introduce the meson transition form factor project with special emphasis on the interrelations between the various form factors (on-shell, single off-shell, double off-shell). Short summaries of the talks presented at the workshop follow.Comment: 69 pages, 14 figures; all talks can be found at https://sites.google.com/site/mesonnetwork/home/activities/form-factor-workshop-2012; v2: workshop link updated (as the page had to be moved to a commercial server), table 6 correcte

An Intersectional Lens to COVID-19: Promoting Youth Well-Being in the Midst of Social-Political Stressors

Guided by interpretative phenomenological methodology and intersectionality theory, this thesis aims to uncover the mental health experiences of youth surrounding the COVID-19 pandemic. This study also seeks to situate these experiences with the subsequent stressors that young people face in the current social-political context (e.g., witnessing trauma in the media, uprisings to address racism and the resulting backlash, rhetoric of the 2020 presidential election). Furthermore, this thesis aims to give insight and voice how intersectionality shapes the COVID-19-related experiences of youth in South Carolina. Data was collected through semi-structured interviews with 23 participants aged 16-21 years old in South Carolina. Findings reveal the mental health experiences of youth during the COVID-19 pandemic including a concern for self (e.g., increased mental stress from the closing of schools) and social-political conditions (e.g., 2020 presidential election, uprisings to address racism). Findings also reveal that identities and systems of power and oppression shaped youth’s experiences during the pandemic and social-political context (e.g., witnessing social injustices). Finally, young people bring to light the ways they were able to thrive, resist, and take care of their well-being both during the pandemic and in related social-political context including mental health habits (e.g., therapy), physical health habits (e.g., exercise), social media, and social support. This thesis also acknowledges participants lived experiences, ideas, and solutions to inform mental health support (e.g., policies, programs, and practices) for youth during and beyond the pandemic

Eta physics at threshold

The production of eta and eta-prime mesons in elementary nucleon-nucleon collisions has been investigated at the synchrotrons CELSIUS, COSY and SATURNE. The magnitude and energy dependence of the total cross section as well as the occupation distribution of the phase space serve as observables for investigating the mechanisms underlying the production processes and the interaction of mesons with nucleons. The precise data on the eta and eta-prime creation via the pp --> pp eta(eta-prime) reactions allowed to settle the general features of the eta and eta-prime meson production and revealed the sensitivity of the mentioned observables to the nucleon-nucleon-meson final state interaction. The particular production properties, like for example the determination of the dominating exchange processes which lead to the excitation of the S_11 nucleon isobar in the case of eta creation, must be established by confrontation with other observables. The present status of this investigation with an emphasis on the results of the COSY-11 collaboration is briefly presented. The available data are interpreted in view of the production mechanism and the meson-nucleon interaction.Comment: 3 pages, 3 figures, Presented at Conference on Quarks and Nuclear Physics (QNP 2002), Julich, Germany, 9-14 Jun 200

On the close to threshold meson production in neutron-neutron collisions

A method of measuring the close to threshold meson production in neutron-neutron collisions is described where the momenta of the colliding neutrons can be determined with the accuracy obtainable for the proton-proton reaction. The technique is based on the double quasi-free nn --> nn X^0 reaction, where deuterons are used as a source of neutronsComment: 6 pages, 2 figures, to be published in Phys. Lett.

S-wave eta'-proton FSI; phenomenological analysis of near-threshold production of pi0, eta, and eta' mesons in proton-proton collisions

We describe a novel technique for comparing total cross sections for the reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta' close to threshold. The initial and final state proton-proton interactions are factored out of the total cross section, and the dependence of this reduced cross section on the volume of phase space is discussed. Different models of the proton-proton interaction are compared. We argue that the scattering length of the S-wave eta'-proton interaction is of the order of 0.1 fm.Comment: 10 pages, 5 figure