мени потрибно, щоб ти у тексті замінив слова на більш зрозумілі синоніми. АЛЕ НАУКОВУ ЛЕКСИКУ НЕ ЧІПАЙ, ТАКАЖ САМА ВОНА ПОВИННА БУТИ. простто зроби текст трішки проще, типу я його самостійно перекладала. ПЕРЕКЛАД ТАКИЙ САМИЙ АНГЛІЙСЬКОЮ. ПРОСТО ЙОГО ЗРОБИТИ ТРІШКИ ЛЕГШЕ



While studying radiation that is emitted in a radioactive decay, a zero-energy peak is always observed in the electron spectrum, which reflects the distribution of electrons with the maximum intensity at the energy E ≤1eV and a halfwidth of 1–2 eV. The in-tensity of this distribution falls down so rapidly that it can be neglected at energies higher than 15–20 eV. Those electrons are called near-zero ones. We designate them as e0-electrons, in contrast to fast electrons, which are designated as ef-electrons.



For the first time, the zero-energy peak was found in work, when analysing the low-energy part of the electron spectrum emitted by 239Pu. For its registration, an ordinaryβ-spectrometer with a Geiger-Müller counter was used, although it is efficient for the registration of only electrons with energies of tens kiloelectronvolts and higher. Therefore, for the spectrum to be registered, electrons were preliminarily ac celerated to the energy E. It turned out that the peak is also located at the energy E, i.e. the own energy of the observed electrons was close to zero. The authors of work explained the appearance of this peak by the field emission. However, in work, in addition to aβ-spectrometer, an electrostatic analyser was applied, which allowed the experimenters to exclude the emergence of the field emission. Nevertheless, the zero-energy peak was always present in all spectra of investigated radioactive sources. The authors called it “zero-energy peak” and explained its emergence as a result of the secondary Auger electron emission, frozen primary or secondary electrons generated in the source or substrate by α- or β-particles, or γ-quanta.


However, the most detailed analysis of the zero-energy peak was carried out in work with the help of a specially constructed electrostatic spectrometer with high resolution. The intensity and the shape of a spectral distribution were found to depend on the temperature, thermal treatment, vacuum, and other factors. A conclusion was drawn that the origin of the zero-energy peak is associated with the state of the radioactive source surface. It was suggested to call this phenomenon as the radiation-induced electron emission (RIEE) and to determine it as follows: “RIEE is a genuine secondary emission of adsorbates invoked by radioactive radiation”. Electrons are emitted from the surface of the source rather than from its bulk. At the same time, the properties of the surface are governed by properties of the electron system located on the surface of the adsorbed film. Therefore, e0-electrons arise at the source surface; however, the reason for the emission emergence and how it occurs are not contained in the definition of RIEE.


In work, under ultrahigh vacuum conditions, the specimen surface was cleaned using inert gases, and the zero-energy peak was simultaneously measured. The peak intensity was shown to decrease with increase in the time duration of the surface cleaning procedure, maybe owing to a reduction in the number of e0-electrons on the surface. Our work is not aimed at explaining the reasons for why e0-electrons emerge on the surface. The main purpose of our researches is to explain the origin of the e0-electron emission into vacuum at the radioactive decay or when charged particles pass through a target.



Our model consists in that the emission of e0-electrons from the surface of a radioactive source is stimulated by the sudden emergence of an electric charge near the surface. This charge appears immediately at the time moment of a radioactive decay or when a charged particle crosses the surface. The emission of e0-electrons from the surface is a partial case of the shakeoff effect. The latter has been studied the most comprehensively in the case of β-decay, when an electron is shaken off from the atomic shell, and, as a result, the charge of the nucleus changes by +1 in a jump-like manner. In a series of works, we analysed the yield Y of e0-electrons into vacuum and its dependence on the kind of radioactive decay, radioactive source thickness, magnitude of charge that arises in the course of the radioactive decay, and velocity of charged particles that cross the target surface. In this work, our efforts will be focused on the determination of the e0-electron distribution over energies and the binding energy of e0-electrons, En, before they are emitted from the source or target surface.



However, first of all, let us consider, in more details, the e0-electron emission as a result of the sudden emergence of an electric charge near the surface, i.e. the shakeoff effect. The model is based on the theoretical ideas set in works and follows from the solution of a non-stationary Schrödinger equation obtained in the first order of perturbation theory.