CHAPTER 3 RESULTS - Wavelength measurements and microphotometer traces have been made for certain selected spectral regions shown in column 5 of Table 1.1. It was not considered necessary for this report to measure the spectra of all shots already taken up to Ivy. For example, are almost exact duplicates, as are Tumbler-Snapper 1 and 3. _agrees weil with Tumbler-Snapper 2 below 4000 A exceptthat it does not have as strong Schumann-Runge bands of oxygen there. The regions studied for the various plates lie, in general, between 3000 and 5000 A. Measurements were not extended above 5000 A because of the great agreement between absorption structure observed there and the absorption spectrum of the atmosphere. An absorption continuum, possibly due to ozone, blotted out the spectrum below about 3000 A. t The bulk of the line and band structure appears in, absorption (hence nearly all measurements concern absorption), but emission is also present in some cases. For example, the structure of the Tumbler-Snapper 4 spectrum at its long-wavelength end is almost completely in emission. Sometimes it was difficult to distinguish between emission and absorption since both seemed to exist side by side on the plate. Many wavelengths have been identified, and the materials contributing prominently to the observed structure are listed for the various shots in column 6 of Table 1.1. The main contribution comes from the Schumann-Runge system of oxygen; other more or lesa prominent molecules observed were NO,, HNO;, OH, and Nf. Spectral lines of several atoms were found, iron being the one found mostoften. Its presence is attributed to the casing of the bombor to tower materials and is not held to be of first importance in this report. However, column 7 of Table 1.1 gives an indication of the appearanceof iron in the spectra for various shots. For example, iron lines are quite prominent in Buster Baker and Tumbler-Snapper 2 and not observed in Mike or King. Prints of the actual spectra in the 3000 to 4000 A region for several shots are shown in Fig. 3.1. With the exception of Mike, the spectra are positive prints; i.e., an emission line is bright and an absorption line is dark. The reverse is true for Mike. In some cases a comparison spectrum of iron is shown—as for Tumbler-Snapper 2——to show coincidences. The wavelengths of the heads of selected bands are identified in order to facilitate visual comparison of the strengths of the bands in various shots. Figure 3.1 shows that the S-R 3516 (0-15) band of O, in Tumbler-Snapper 4 has about a dozen lines. In Tumbler-Snapper 3 this band is considerably longer and somewhatstronger, extending as far as the head of the S-R band at 3673 A. A comparison of Mike and Tumbler-Snapper 7 in the region above 4200 A is also shown in Fig. 3.1. The absorption peaks in Mike are broad and fuzzy compared with the other spectra. 16