Heavy ion emission

The nuclides in the natural radioactive decay chains are not the most favorable candidates for heavy ion emission they have unfavorable N/Z ratios. As shown in the example of emission of oxygen isotopes by Th, emission of a Z = JVfragment leads to a product that is far from the center of P stability. Of course, emitting a fragment with N> Z (e.g., °0) displaces the emitted... 

Instances of heavy ion emission by members of the natural decay chains... 

Heavy ion emission would be grouped with spontaneous fission and not considered in this chapter were it not for the convenience the chains afford as a source of radioactive materials with which to study the process. Products such as Ra can be produced in charged-particle bombardments, but that implies the presence of energetic ions, which can complicate the detection of a few heavy ions from decay. The ranges of the heavy ions emitted by processes analogous to a decay are a few milligrams per square centimeter. Thin sources are needed, and the carrier-free materials that can be isolated from the chains serve this purpose well. It is likely that heavy particle emission will be found to be a decay mode for most heavy elements. 

B. Low-Energy Electron Emission in Fast Heavy-Ion-Atom Collisions 1. Longitudinal Electron Velocity Distributions... 

More details of the emission of ultralow- and low-energy electrons from fast heavy ion-atom collisions may be seen in the doubly differential cross sections as functions of the longitudinal electron velocity for increasing transverse electron velocity. Examples considered in this chapter include singly ionizing... 

N. Stolterfoht, R. D. DuBois, and R. D. Rivarola, Electron Emission in Heavy-Ion Atom Collisions, Vol 20, J. P. Toennies, ed., Springer-Verlag, Berlin, 1997. 

Stolterfoht, N. DuBois, R.D. Rivarola, R.D. In Electron Emission in Heavy Ion-Atom... 

The main aim of this paper is to review the CDW-EIS model used commonly in the decription of heavy particle collisions. A theoretical description of the CDW-EIS model is presented in section 2. In section 3 we discuss the suitablity of the CDW-EIS model to study the characteristics of ultra-low and low energy electrons ejected from fast heavy-ion helium, neon and argon atom collisions. There are some distinct characteristics based on two-centre electron emission that may be identified in this spectrum. This study also allows us to examine the dependence of the cross sections on the initial state wave function of multi-electron targets and as such is important in aiding our understanding of the ionization process. 

Because the particles in these storage rings lose energy by emission of synchrotron radiation, further acceleration is necessary. The energy loss by synchrotron radiation is relatively high in the case of electrons and low in the case of heavy ions. 

The K(3 IKOi x-ray intensity ratio is an easily measurable quantity with relatively high precision and has been studied extensively for /f-x-ray emission by radioactive decay, photoionization, and charged-particle bombardment (1-3). Except for the case of heavy-ion impact where multiple ionization processes are dominant, it is generally accepted that this ratio is a characteristic quantity for each element. The experimental results are usually compared with the theoretical values for a single isolated atom and good agreement is obtained with the relativistic self-consistent-field calculations by Scofield (4). 

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