The classical integrability the O(N) nonlinear sigma model on a half-line is examined, and the existence of an infinity of conserved charges in involution is established for the free boundary condition. For the case N = 3 other possible boundary conditions are considered briefly.

A nonperturbative kinetic/magnetohydrodynamics eigenvalue code has been constructed for calculation of kinetic damping of shear Alfvén eigenmodes in general tokamak geometry with finite pressure. The model describes shear Alfvén waves with kinetic effects from thermal species including thermal ion finite Larmor radius effects and parallel electric field. An analytic formula for the radiative damping of reversed shear Alfvén eigenmodes is obtained for tokamak plasmas with reversed shear q profile. Numerical calculations reveal the existence of multiple kinetic reversed shear Alfvén eigenmodes (KRSAEs). It is found that the damping rate of the KRSAEs scales linearly with the thermal ion gyroradius. The damping rates are larger for modes with more peaks in the radial structures. These results are consistent with analytic expectation. The KRSAEs found here can be used to interpret the RSAEs frequency sweeping down observed sometime in the tokamak experiments.

The physics reach of a low threshold (100 eV) scintillating argon bubble chamber sensitive to Coherent Elastic neutrino-Nucleus Scattering (CEνNS) from reactor neutrinos is studied. The sensitivity to the weak mixing angle, neutrino magnetic moment, and a light Z gauge boson mediator are analyzed. A Monte Carlo simulation of the backgrounds is performed to assess their contribution to the signal. The analysis shows that world-leading sensitivities are achieved with a one-year exposure for a 10 kg chamber at 3 m from a 1 MW th research reactor or a 100 kg chamber at 30 m from a 2000 MW th power reactor. Such a detector has the potential to become the leading technology to study CEνNS using nuclear reactors.

Abstract. -The behavior of spiral turbulence in mechanically deformed excitable media is investigated. Numerical simulations show that when the forcing frequency is chosen around the characteristic frequency of the system, complicated spiral turbulence may be quenched within a shorter evolution time, compared to the case free of mechanical deformation. It is shown that the observed phenomenon occurs due to enhancing the drift of spiral tips induced by mechanical deformation.A wide range of self-organized phenomena exists in spatially distributed systems. One of the most paradigmatic examples of spatiotemporal self-organized structures is a class of spiral waves, which have been observed in a variety of physical [1], chemical [2][3][4][5] and biological systems [6][7][8][9]. The attractiveness of investigating the dynamics of spiral waves is not only because they own a special structure, i.e., the core regarded as a phase-singular in mathematical language, but more important they contribute to the underlying class of cardiac disease also, such as tachycardia and fibrillation [6][7][8][9]. It is thus that, from a practical point of view, controlling the behaviors of spiral waves, particularly eliminating spiral waves and spiral turbulence, is extremely important and meaningful. Up to now, various methods to control two-, and even three-dimensional spiral waves and turbulence have been put forward [10][11][12][13][14][15][16][17][18][19].On the other hand, Munuzuri et al. [20] designed an appropriate elastic excitable medium by incorporating the BZ reaction into a polyacrylamide-silica gel and experimentally studied the influence of periodic mechanical contraction of excitable media on the behavior of rotating spiral waves. Recently, we derived, directly from origin reaction-diffusion equations, a formula of drifting velocity using weak-deformation approximation and explained the drift of spiral waves under resonant frequency [21]. Besides, spiral breakup due to mechanical deformation was studied in our recent work [22]. To our knowledge, however, the influences of mechanical