Interaction of ultrarelativistic electron and proton bunches with dense plasmas

Here we discuss the possibility of employment of ultrarelativistic electron and proton bunches for generation of high plasma wakefields in dense plasmas due to the Cherenkov resonance plasma-bunch interaction. We estimate the maximum amplitude of such a wake and minimum system length at which the maximum amplitude can be generated at the given bunch parameters.Comment: 8 page

Real-life impact of COVID-19 pandemic lockdown on the management of pediatric and adult asthma: A survey by the EAACI Asthma Section

Background: The restrictions imposed by the COVID-19 pandemic impact heavily the management of chronic diseases like asthma. This study aimed to evaluate the management of adults and children with asthma during COVID-19-related lockdown. Methods: A survey was launched by the European Academy of Allergy and Clinical Immunology (EAACI) via e-mail, website, and social media to EAACI members and members of peer societies. Results: The survey was completed by 339 healthcare professionals from 52 countries. 79% of follow-up consultations were replaced by phone calls, whereas 49% of newly referred patients attended the clinic. 62%, 76%, 66%, 76%, and 87% of responders did not conduct spirometry, impulse oscillometry, bronchodilator test, FeNO, or methacholine provocation, respectively, for asthma diagnosis in adults. The numbers were similar for children. 73% of responders based the initial asthma diagnosis and the prescription of inhaled therapy on clinical parameters only. Lung function tests were used in 29% of cases to monitor asthma worsening, and only 56% of participants were recommended to their patients ambulatory peak expiratory flow (PEF) measurements. Using a 1 (not at all) to 5 (very much) scale, the responders considered that the quality of healthcare provided and the patients’ asthma status had deteriorated during the lockdown with 3.2 points and 2.8 points, respectively. Conclusion: Collectively, these results suggest that all necessary resources should be allocated to ensure the performance of lung function tests for initial diagnosis, whereas digital remote monitoring should be reinforced for the follow-up of children and adults with asthma

Pulse Shape Analysis and Identification of Multipoint Events in a Large-Volume Proportional Counter in an Experimental Search for 2K Capture Kr-78

A pulse shape analysis algorithm and a method for suppressing the noise component of signals from a large copper proportional counter in the experiment aimed at searching for 2K capture of Kr-78 are described. These signals correspond to a compound event with different numbers of charge clusters due to from primary ionization is formed by these signals. A technique for separating single- and multipoint events and determining the charge in individual clusters is presented. Using the Daubechies wavelets in multiresolutional signal analysis, it is possible to increase the sensitivity and the resolution in extraction of multipoint events in the detector by a factor of 3-4.Comment: 10 pages, 8 figures. submitted to Instruments and Experimental Techniques; ISSN 0020/441

Searches for neutrinoless double beta decay

Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.Comment: 8 pages, prepared for TAUP 201

Vlasov-Maxwell, self-consistent electromagnetic wave emission simulations in the solar corona

1.5D Vlasov-Maxwell simulations are employed to model electromagnetic emission generation in a fully self-consistent plasma kinetic model for the first time in the solar physics context. The simulations mimic the plasma emission mechanism and Larmor drift instability in a plasma thread that connects the Sun to Earth with the spatial scales compressed appropriately. The effects of spatial density gradients on the generation of electromagnetic radiation are investigated. It is shown that 1.5D inhomogeneous plasma with a uniform background magnetic field directed transverse to the density gradient is aperiodically unstable to Larmor-drift instability. The latter results in a novel effect of generation of electromagnetic emission at plasma frequency. When density gradient is removed (i.e. when plasma becomes stable to Larmor-drift instability) and a $low$ density, super-thermal, hot beam is injected along the domain, in the direction perpendicular to the magnetic field, plasma emission mechanism generates non-escaping Langmuir type oscillations which in turn generate escaping electromagnetic radiation. It is found that in the spatial location where the beam is injected, the standing waves, oscillating at the plasma frequency, are excited. These can be used to interpret the horizontal strips observed in some dynamical spectra. Quasilinear theory predictions: (i) the electron free streaming and (ii) the beam long relaxation time, in accord with the analytic expressions, are corroborated via direct, fully-kinetic simulation. Finally, the interplay of Larmor-drift instability and plasma emission mechanism is studied by considering $dense$ electron beam in the Larmor-drift unstable (inhomogeneous) plasma. http://www.maths.qmul.ac.uk/~tsiklauri/movie1.mpg * http://www.maths.qmul.ac.uk/~tsiklauri/movie2.mpg * http://www.maths.qmul.ac.uk/~tsiklauri/movie3.mpgComment: Solar Physics (in press, the final, accepted version

Searches for neutrinoless double beta decay

Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.Comment: 8 pages, prepared for TAUP 201

Searches for neutrinoless double beta decay

Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.Comment: 8 pages, prepared for TAUP 201

Erratum: Production and validation of scintillating structural components from low-background Poly(ethylene naphthalate)

[no abstract available

Canonical quantization of electromagnetism in spatially dispersive media

Copyright © 2014 IOP PublishingOpen Access JournalWe find the action that describes the electromagnetic field in a spatially dispersive, homogeneous medium. This theory is quantized and the Hamiltonian is diagonalized in terms of a continuum of normal modes. It is found that the introduction of nonlocal response in the medium automatically regulates some previously divergent results, and we calculate a finite value for the intensity of the electromagnetic field at a fixed frequency within a homogeneous medium. To conclude we discuss the potential importance of spatial dispersion in taming the divergences that arise in calculations of Casimir-type effects.EPSR