A1203-3H20), chlorinated aluminum oxide (AUOa-HCl), and carbonated aluminum oxide (Al203-C02) contribute to air pollution as products of the corrosion of air conditioners. In cold rooms at temperatures of 3-6°C, this pollutant precipitates from the air coating all surfaces in the rooms

The 9Be(γ,n0)8Be and 9Be(γ,n1)8Be reactions were studied in the photon energy region 18 to 26 MeV. The integrated cross section of the (γ,n0) reaction was found to be less than 0.1 MeV mb in this energy region. The integrated cross section for the (γ,n1) reaction in the energy region is 2.4 ± 0.4 MeV mb, which is 10 to 15% of the total photoneutron cross section. The measured angular distributions for the (γ,n1) reaction are consistent with the population of 3/2+ and 5/2+ states of 9Be. These results are consistent with slightly re-interpreted predictions of Majling, Kukulin, and Smirnov.

Alpha particles from the 9Be(γ,n)8Be(16.6) and 9Be(γ,α0)5He reactions were studied in the photon energy region 18 to 26 MeV; the results yielded a combined integrated cross section of 13.1 ± 2 MeV mb and an upper limit on the integrated (γ,α0) cross section of 4.0 MeV mb. This agrees within error with the integrated cross section of Becchi, Meneghetti, Sanzone, and Vitale, 10 ± 2 MeV mb, which would contain about 50% of any contribution from the (γ,α0) reaction. These reactions together with the 9Be(γ,n1)8Be reaction (which has an integrated cross section of 2.4 ± 0.4 MeV mb) are the major reaction channels contributing to the total photoneutron cross section in this energy region. Their sum, 15.5 MeV mb, agrees well with the results of Nathans and Halpern and Hughes, Sambell, Muirhead, and Spicer but disagrees with that of Costa, Pasqualini, Piragino, and Roasio.

The spectra of deexcitation gamma rays following photodisintegration of 19F and 31P have been measured to study further the reaction channels involved in photodisintegration of nonclosed shell nuclei. Besides (γ,n) and (γ,p) decays to excited states of the residual nuclei, strong (γ,α) channels from 19F to the first excited state of 15N and from 31P to the first two excited states of 27Al were observed.

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