Spin alignment production

A. Production of State of Spin Alignment by Optical Pumping... 

The square of the wavefunction, for a given configuration (orbital occupation), is interpreted as the electron density at that point in space. Since the electronic Hamiltonian does not explicitly have a term for spin, our wavefunction does not either. To completely describe the electron distribution the spin coordinate, i, must be included. The spin coordinate takes on two values -I- V2 and — V2. The spin wavefunction for spin aligned along the positive z-axis is a(C), and the spin wavefunction for spin aligned along the negative z-axis is P( ). The product of the spatial wavefunction (atomic orbital) < )(r) and the spin wavefunction a( ) or P( ) is the complete wavefunaion and is called a spin-orbital, denoted by x(f, Q. For an -electron system, the simplest wavefunction would be in the form of a product of spin-orbitals. 

Although there are many variations on how carbon fibers are made, the typical process starts with the formation of PAN fibers from a conventional suspension or solution polymerization process between a mixture of acrylonitrile plastic powder with another plastic, such as methyl acrylate or methyl methacrylate, and a catalyst. The product is then spun into fibers, with the use of different methods, in order to be able to achieve the internal atomic structure of the fiber. After this, the fibers are washed and stretched to the desired fiber diameter. This step is sometimes called "spinning" and is also vital in order to align the molecules inside the fiber and thus provide a good basis for the formation of firmly bonded carbon crystals after carbonization [7]. 

The transformation of this molecular rotational order into nuclear spin order during the hydrogenation reaction leads to typical polarization patterns in the NMR spectra of the hydrogenation products. Depending on whether the experiment is performed inside or outside of a magnetic field (see Fig. 21.6), these types of experiments have been referred to under the acronyms PASADENA (Para-hydrogen and Synthesis Allow Dramatically Enhanced Nuclear Alignment) or... 

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