Time Dependence of Mössbauer γ‐Radiation Modulated by Acoustic Excitations

Abstract

In recent years there appear more and more works on time-dependent differential Mossbauer spectroscopy since it enables us to investigate various posteffects of electron capture, transient processes, relaxation of local oscillating and electronic excitations with the relaxation time of the order of and less than the lifetime of the nuclear level, dynamic behaviour of the nuclei in different media, etc. /1 to 9/. Particularly, quantum beats of r-radiation /8, 9/ may be used to measure small energy shifts, e.g. gravitational, complex oscillations, single pulses, etc.values of the absorber effective thickness and of an arbitrary form and frequency of acoustic oscillations, unlike paper /9/ dealing only with sinusoidal high-frequency oscillations.The present note considers beats of the resonance r-radiation at arbitrary Further we proceed by distinguishing two cases: a) the high frequency case SZ>r where 51 is the oscillation frequency and ro is the natural linewidth of the nuclear level, and b) the low frequency case 0 G ro. cording to the periodic law A = xof(!G? t) where A. is the oscillating amplitude. For the electric field of the frequency modulated radiation of that nucleus 0 a) High-frequency case Let us consider an excited nucleus oscillating ac-where uo is the radiation frequency, a = k lo is the modulation index, k' is the wave vector of the r-quantum,and t is the beginning of the given nuclear emission. 0 1) 375019 Erevan, USSR.