Bismuth-209, excitation

Electron spin echo envelope modulation (ESEEM) and ENDOR have been used to study the overlap of the donor wavefunction with naturally-occurring Si. Low-field (6-110 mT) measurements with 50 MHz and 200 MHz excitation showed that the bismuth excitation energy could be tuned for future coupling with superconducting qubits,which require low magnetic fields. Si Bi has electron spin coherence times that are at least as long as Si P with natural silicon and isotopically-pure Si (ref. 76). Like Si P, Si Bi is suitable for bound exciton experiments including nuclear hyperpolarization. ... 

The deep violet color of pentaphenylbismuth and certain other pentaarylbismuth compounds has been the subject of considerable speculation. It has been shown by x-ray diffraction (173) that the bismuth atom in pentaphenylbismuth is square—pyramidal. WeU-formed crystals are dichromic, appearing violet when viewed in one plane but colorless in another plane. The nature of the chromophore has been suggested to be a charge-transfer transition by excitation of the four long equatorial bonds ... 

These fissioning nuclei (such as 8tP°i2-211> formed by reaction of Bi209 and a deuteron) have a nearly spherical normal-state structure, resembling that of the doubly magic nucleus seP m208, with an outer core of 16 spherons and an inner core of 4 spherons, shown in Fig. 6. The nucleus is excited, with vibrational energy about 25 Mev (for bismuth bombard-... 

Radiation is derived from a sealed quartz tube containing a few milligrams of an element or a volatile compound and neon or argon at low pressure. The discharge is produced by a microwave source via a waveguide cavity or using RF induction. The emission spectrum of the element concerned contains only the most prominent resonance lines and with intensities up to one hundred times those derived from a hollow-cathode lamp. However, the reliability of such sources has been questioned and the only ones which are currently considered successful are those for arsenic, antimony, bismuth, selenium and tellurium using RF excitation. Fortunately, these are the elements for which hollow-cathode lamps are the least successful. 

Numerous nuclear reactions have been employed to produce astatine. Three of these are particularly suited for routine preparation of the relatively long-lived isotopes with mass numbers 209, 210, and 211. The most frequently used is the ° Bi(a,xn) At (a = 1-4) reaction, in which bismuth 44, 74,120) or bismuth oxide (7,125) is bombarded by 21-to 40-MeV a-particles. The ° Bi(He, xn) At reaction can also be used to produce isotopes of astatine 152), the nuclear excitation functions (62) favor a predominant yield of ° At and °At. The routine preparation of astatine is most conveniently carried out through the ° Bi(a,xn) At nuclear reactions, from which a limited spectrum of astatine nuclides may be derived. The excitation functions for these nuclear reactions have been studied extensively (78, 89, 120). The... 

Science in its youth is always exciting to pursue. When I began my career forty years ago, aluminum chemistry was a newly emerging field. Thus, whatever I found was new and exciting. I am sure that every young researcher who is interested in bismuth chemistry will enjoy the still-unfolding era of this element prior to its full blooming - and I am also confident this book will provide a reliable compass for his or her journey of discovery. 

Of the above three s ions, most data have been obtained for Pb . The reason is that this ion gives the best Sq -> Pj absorption spectrum the bismuth(III) spectral band tends to be somewhat broad (see above) and the thallium (I) band often has a shoulder, or even consists of two distinct maxima, an effect which has been attributed possibly to the Jahn-TeUer effect in the excited state (75). From Eq. (2) and data in... 

A somewhat related breakthrough in elemental fluorine chemistry by Bastian and Ruppert, which is extremely exciting, involves the selective oxidation of phosphorous (61), arsenic (62), antimony (62), and bismuth (62) without fluorine substitutions occurring on the phosphorane, arsane, and so on. 

Further comments on the size and extent of this bismuth cross-section calculational effort should be made. Table 5 summarizes the number of target states that we will need to consider (the 21 states include both ground and isomeric states), the number of separate reaction excitation functions that must be included, as well as estimates of the number of computer runs and the CDC 7600 CPU computer time that will be required. In our calculations, we typically use energy-bin sizes of 10 to 250 keV, depending on the reaction type and the energy ranges of concern. 

Several investigations have been reported of excitation transfer from excited mercury atoms to ground-state atoms of silver, bismuth, cadmium, chromium, copper, indium, lead, and zinc. Most of these experiments which had been completed some time ago were surveyed by Seiwert [6,7]. Perhaps of particular interest is an investigation by Gough [105], who studied excitation transfer from mercury to cadmium and concluded that not only excitation energy but also coherence was transferred in the collisions. A similar conclusion was reached by Kraulinya, Sametis, and Bryukhovetskii [106] as the result of their study of the Hg-Tl system. Cross sections for Hg-Cd... 

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