Alpha particles and decay

Ratio adjusted for uranium amount of net alpha-particle and decay-corrected beta-particle counting rates in Table 7.3 to Table 7.2 (alpha) (beta) ... 

A specific cause of potential contamination is counting radionuclides that emit alpha particles and decay to progeny radionuclides such sources cannot be covered, and the progeny may leave the source due to recoil (see Section 2.2.1). One possible means of control is to keep the recoiling radionuclide on the source mount by an applied negative charge. 

There are three common ways by which nuclei can approach the region of stability (1) loss of alpha particles (a-decay) (2) loss of beta particles (/3-decay) (3) capture of an orbital electron. We have already encountered the first type of radioactivity, a-decay, in equation (/0). Emission of a helium nucleus, or alpha particle, is a common form of radioactivity among nuclei with charge greater than 82, since it provides a mechanism by which these nuclei can be converted to new nuclei of lower charge and mass which lie in the belt of stability. The actinides, in particular, are very likely to decay in this way. 

As early as 1902, Rutherford and his colleague, the chemist Frederick Soddy, realized that emissions of alpha and beta rays changed the nature of the emitting substance. One example of such a change is the spontaneous radioactive decay of the uranium-238 isotope, which emits an alpha particle and produces thorium ... 

The radiation from exposure to americium is the primary cause of adverse health effects from absorbed americium. Upon entering the body by any route of exposure, americium moves relatively rapidly through the body and is concentrated in bones where it remains for a long time. While in the bone, americium atoms decay, releasing alpha particles and gamma-rays. Alpha... 

The ionic charge, diffusivity, and electrical mobility associated with these small radioactive particles are three parameters controlling plateout. A particle can acquire an electrical charge by a number of mechanisms which promote the transfer of electrons to and from the particle surface, therefore producing a negatively and positively charged particle, respectively. With the decay of Rn-222, an alpha particle and Po-218 are formed. As these... 

One-sixteenth will remain after 4 half-lives, so 4 X 30 = 120 years. 71. Eight alpha particles and six beta particles are emitted in the decay chain from U-238 to Pb-206. (The numbers are the same for the alternate routes.)... 

Alpha decay is characterized by the emission of an alpha particle from the parent nucleus. In this process, energy is released in the form of kinetic energy of the escaping alpha particle and the recoiling daughter nucleus. For example ... 

Te 5.10 alpha particles and 5 beta particles 7. Refer to Table 21.2 for potential radioactive decay processes. 17F and, 8F contain too many protons or too few neutrons. Electron capture or positron production are both possible decay mechanisms that increase the neu-tron-to-proton ratio. Alpha-particle production also increases the neu-tron-to-proton ratio, but it is not likely for these light nuclei. 21F contains too many neutrons or too few protons. Beta-particle production lowers the neutron-to-proton ratio, so we expect 21F to be a /3-emitter. 9. a. 2gCf + gO - fcIJSg + 4jn b. Rf 11. 6.35 X 1011 13. a. 

Gamow s research career focused on two major fields, seemingly about as far apart as one can imagine nuclear physics and astronomy. In his work on nuclear physics, he devised explanations for two ways in which nuclei can decay, by the loss of alpha particles and by the emission of beta particles. During World War II, he was a member of the Manhattan Project, the program for the development of the first atomic (fission) bomb, and he was later involved in work on the first hydrogen (fusion) bomb. 

Radium 223 is promising in the treatment of bone cancer, as it has only a half-life of 11 days, short half-lives of all daughter isotopes, and produces multiple alpha particles per decay. It is now marketed in the chemical form 223RaCl2. 

Lil(Eu). Lil(Eu) is an efficient thermal-neutron detector through the reaction jLKn, a)jH. The alpha particle and the triton, both charged particles, produce the scintillations. Lil has a density of 4.06 X 10 kg/m, decay time of about 1.1 /i,s, and emission spectrum peaking at 470 nm. Its conversion efficiency is about one-third of that for Nal. It is very hygroscopic and is subject to radiation damage as a result of exposure to neutrons. 

Boron-10 emits alpha particles and cesium-137 emits beta particles. Write balanced nuclear reactions for each radioactive decay. 

Knowledge Required (1) The general composition of atomic nuclei (numbers of neutrons and protons). (2) The modes of radioactive decay available to nuclei. (3) The meanings of the terms alpha particle and beta particle. 

Plutonium isotopes of interest are listed in Table 6.3. All except Pu emit alpha particles, 14-keV L X rays, and multiple weak gamma rays " Pu emits beta particles that decay to Am, which emits alpha particles and gamma rays. Single or multiple neutron reactions with and form all of the isotopes. The isotopes that emit alpha particles have numerous unlisted minor gamma-ray transitions. 

An element P, radloactively decays to an element Q with the emission of an alpha particle. Q decays to element R by beta emission and R decays to element S by beta emission. What can you state about P and S7... 

Mode of decay Alpha particles and weak gamma radiation... 

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