Based on experimental observations using the TUMAN-3M and FT-2 tokamaks, and the results of gyrokinetic modeling of the interplay between turbulence and the geodesic acoustic mode (GAM) in these installations, a simple model is proposed for the analysis of the conditions required for L-H transition triggering by a burst of radial electric field oscillations in a tokamak. In the framework of this model, one-dimensional density evolution is considered to be governed by an anomalous diffusion coefficient dependent on radial electric field shear. The radial electric field is taken as the sum of the oscillating term and the quasi-stationary one determined by density and ion temperature gradients through a neoclassical formula. If the oscillating field parameters (amplitude, frequency, etc) are properly adjusted, a transport barrier forms at the plasma periphery and sustains after the oscillations are switched off, manifesting a transition into the high confinement mode with a strong inhomogeneous radial electric field and suppressed transport at the plasma edge. The electric field oscillation parameters required for L-H transition triggering are compared with the GAM parameters observed at the TUMAN-3M (in the discharges with ohmic L-H transition) and FT-2 tokamaks (where no clear L-H transition was observed). It is concluded based on this comparison that the GAM may act as a trigger for the L-H transition, provided that certain conditions for GAM oscillation and tokamak discharge are met.

Ion cyclotron emission (ICE) observation in neutral beam injection (NBI)-heated plasma in the TUMAN-3M tokamak is reported. Experiments were performed in deuterium or hydrogen target plasmas, with the neutral heating beam consisting of 60% deuterium and 40% hydrogen atoms accelerated up to 16 keV. High-frequency internal magnetic probes were used as a diagnostic tool for ICE detection. In deuterium plasmas, emission with ~13 MHz frequency was observed, with 1–2 ms delay after the NBI pulse front; this frequency corresponds approximately to fundamental ion cyclotron (IC) resonance for hydrogen near the magnetic axis. In hydrogen plasmas, ICE with frequency ~7 MHz was observed. In both cases, the observed frequency scales as IC resonance of minority ions. In deuterium plasmas, the hydrogen minority ICE spectral line was found to consist of several narrow (width ~ 50 kHz) spectral components, typically three or more, with different spacing (of the order of 50–200 kHz), and temporal dynamics in synchronicity with sawtooth oscillations. The ICE with the frequency corresponding to IC resonance for majority ions was also observed in several hydrogen and deuterium discharges. Theoretical models developed for the explanation of NBI ICE on other tokamaks are not easily applicable for the phenomena observed on the TUMAN-3M. In pure ohmically heated deuterium and hydrogen plasmas, i.e. in the absence of fast ions, a weak ICE was also observed, with frequency scaling as IC resonance condition in close proximity to the probe location.

Understanding the successes and failures of management of protected areas is vital for the conservation of global biodiversity. The Management Effectiveness Tracking Tool (METT) is a simple, questionnaire-based approach for assessing protected area management effectiveness (PAME). Since it was developed in 1999, it has become the most widely applied PAME tool, used in at least 127 countries worldwide. This paper reviews the development of the METT and how it has been implemented and adapted. A combination of literature review on implementation and implementation experience from the original authors and key users of the METT confirms that the METT is a relatively quick and simple way of collecting information about the status and trends of management in protected areas, and provides information to help drive management improvements. As such it is suitable for protected area managers, national protected area agencies, donors, and NGOs aiming to improve area management, and as a component of national reporting to the Convention on Biological Diversity. The paper examines issues related to METT implementation and concludes with 12 recommendations, from using the METT to verification of results, which together help ensure the tool is implemented in the most effective way and improves the credibility of PAME assessments.

Results of an experimental study of geodesic acoustic modes (GAM) in the TUMAN-3M tokamak are reported. With Doppler backscattering (DBS) the basic properties of the GAM such as frequency, conditions for the GAM existence and the GAM radial location have been identified. The two-frequency Doppler reflectometer system was employed to reveal an interplay between low frequency sheared poloidal rotation, ambient turbulence level and the GAM intensity. Bicoherence analysis of the DBS data evidences the presence of a nonlinear interaction between the GAM and plasma turbulence.

In the experiments on tangential fuel pellet injection in the TUMAN-3M tokamak an initiation of LH-transition or, in several scenarios—temporal (1–2 ms) confinement improvement with the following backwards transition was observed. To understand the possibility of the transitions, a model calculating the evolution of density and ion temperature profiles under the effect of source profile perturbation and plasma cooling created by pellet evaporation was developed. In the model, a diffusion coefficient depending on radial electric field shear value was used. Turbulence parameters are defined using a gyrokinetic simulation of the experiments with ELMFIRE code. Modeling results are in good agreement with experiments. Using the data obtained from the modeling, non-linear particle flux dependency on density gradient was analyzed; the existence of two stabile solutions for two confinement modes dependent on particle flux value was proved, in agreement with experiments.