Effect of extinction beam-plasma discharge while the injection thermoelectrons during transportation of the electron beam in the forevacuum pressure range

The article presents the results of experiments aimed at studying the effect of low-energy thermoelectrons on the parameters of the beam plasma and plasma of the beam-plasma discharge generated during the transportation of a powerful electron beam in the pressure range of the medium vacuum. It is shown that the injection of a sufficiently small current of low-energy thermoelectrons is capable of violating the conditions for the combustion of the beam-plasma discharge and reducing the power loss of the electron beam for SPR generation. In this case, the plasma concentration decreases by almost an order of magnitude (to 1015 m–3) and the temperature of plasma electrons decreases by almost three (to 0.3 eV).

Hard and soft Lewis-base behavior for efficient and stable CsPbBr3 perovskite light-emitting diodes

All-inorganic CsPbBr3 perovskite is an attractive emission material for high-stability perovskite light-emitting diodes (PeLEDs), due to the high thermal and chemical stability. However, the external quantum efficiencies (EQEs) of CsPbBr3 based PeLEDs are still far behind their organic–inorganic congeners. Massive defect states on the surface of CsPbBr3 perovskite grains should be the main reason. Lewis base additives have been widely used to passivate surface defects. However, systematic investigations which relate to improving the passivation effect via rational molecule design are still lacking. Here, we demonstrate that the CsPbBr3 film’s optical and electrical properties can be significantly boosted by tailoring the hardness–softness of the Lewis base additives. Three carboxylate Lewis bases with different tail groups are selected to in-situ passivate CsPbBr3 perovskite films. Our research indicates that 4-(trifluoromethyl) benzoate acid anion (TBA−) with the powerful electron-withdrawing group trifluoromethyl and benzene ring possesses the softest COO− bonding head. TBA− thus acts as a soft Lewis base and possesses a robust combination with unsaturated lead atoms caused by halogen vacancies. Based on this, the all-inorganic CsPbBr3 PeLEDs with a maximum EQE up to 16.75% and a half-lifetime over 129 h at an initial brightness of 100 cd m−2 is thus delivered.

О разрушении упругих полимерных материалов под воздействием электронного пучка

An explanation for a feature found in several experiments in the general picture of the destruction of non-brittle polymers under the influence of a shock wave initiated by a powerful electron beam is proposed. The distance of the cracking region from the surface of the material affected by the beam to a finite length in depth is associated with the three-dimensional nature of the propagation of elastic waves. The universality of the effect is demonstrated by the simplest isotropic model, which shows that large tensile stresses are effectively generated inside the target at its sufficiently large transverse and longitudinal size, even without taking into account nonlinear and shear processes.

Study of functionality of polymer films by dense electron beams

Methodology of using megavolt electrons for investigation of the functionality of thin polymer films of polycyanurates (PCN) is described. The relevance of research is determined by the prospects of using films as a functional basis for improvement of track-etched technologies of nanoporous nuclear filters, where ionizing radiation is used in most of technological stages of their production. Functionality control is the main criterion for the qualification of films on the suitability for production of nuclear filters on their base. Development of megavolt electrons radiation methods is promising for monitoring the functionality of filters. Radiation technologies are universal and able to provide maximum information content on investigations of the characteristics of materials to qualify them for suitability of practical use. To control the functionality of the films, the methodology for research and testing of thin polymer films using powerful electron beams of 1-2 MeV has been developed. The features of these methods and the results of their application at the control of functionality and for the qualification of the films based on crosslinked polycyanurates, synthesized by in situ polycyclotrimerization of dicyanate ester of bisphenol E in the presence of dimethylphthalate (DMPh) of the composition PCN/DMPh=70/30 wt.%, on the suitability for production of nanoporous track membranes are discussed. Key words: electron beams, nuclear membranes, thermostable polycyanurates, radiation stability, functional testing.

Similarities and Differences between Two Researches in Field Electron Emission: A Way to Develop a More Powerful Electron Source

This paper discusses the similarities and differences between two studies that deal with resin-coated field-emission cathodes. The two works that are compared within this paper are entitled: Hot Electron Emission from Composite-Insulator Micropoint Cathodes and Methods of Preparation and Characterization of Experimental Field- Emission Cathodes. Within the text, both studies are reviewed and put into context, pointing out and commenting the advantageous features of this type of cathodes. The comparison focuses mainly on the method of preparation including deposition of a thin film on the cathode tip and the characterization of the coating itself. The effect of the coating on the field emission is discussed as well. Keywords: Cold field emission, Epoxylite 478, Epoxylite EPR-4.