Rays, cosmic positive

The English physicist Cedi Powell discovered Yukawa s meson in 1947. Powell found evidence of its existence in photographic plates that had been exposed to cosmic rays in the Bolivian Andes. The particle was found to be a little heavier than the muon, and it interacted strongly with nuclei, as Yukawa s particle was expected to do. Unlike the muon, which always carried a negative charge, the new particle could have either a positive or a negative charge, or it could be electrically neutral. 

The hole theory was perceived as a Active mathematical construction and was initially rejected by prominent contemporary physicists such as Pauli and Bohr. The physical reality of antiparticles was not taken seriously even by Dirac himself. In 1931 he wrote about his anti-electron we should not expect to find it in Nature [2]. Surprisingly, the first anti-electrons were discovered already in 1932 by Anderson, who studied cosmic rays in Caltech s magnet cloud chamber. Anderson noticed abnormally bending trajectories indicating the presence of light positively charged particles and, as related by Fowler [3], "could not resist the devastating conclusion that they are caused by positive electrons The first piece of antimatter, a positron, made its physical appearance. 

The primary energy source behind the ion-molecule scheme in interstellar molecular clouds is the cosmic ray ionization of H, H2 and He, which can be transferred efficiently to less abundant atoms or species, notably C, N and O. Thus their effective time scale for ionization is reduced by a factor proportional to their abundance. In addition, exothermic feactions between positive ions and neutrals occur with no... 

Interstellar molecules are detected at the position where they are formed. Their formation mechanism is usually modelled for a steady-state situation, although their abundances are not in thermodynamic equilibrium. Cosmic rays and ultraviolet radiation prevent equilibrium from being reached. Cosmic ray ionization is seen as the driving force for a large number of chemical reactions. 

Primary charged species formed by galactic cosmic ray ionization are N 2, 0 2, O, N, and free electrons. The latter are rapidly attached to gas molecules, giving rise to simple negative ions, mostly 0"2. Subsequent ion molecule reactions of primary positive and negative ions lead to complex positive and negative cluster ions. Ultimately these are removed by ion-ion recombination involving either a binary or a ternary mechanism [33]. 

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