4.8.2
Nitrogen Dioxide
NO, is known to be produced early in the life of an explosion. This is evidenced by its
marked presence in the 0 to 20 msec plate from Buster Charlie and by its presence in greater
strength in the 0 to 100 usec plate from Tumbler-Snapper 7. The spectrum of Tumbler-
Snapper 7 from about 4000 A higher ia essentiallythat of NO,, and below 4000 A there is a
superposition of short S-R bands on the NO, plus broad bands of HNO;. NO; appearsfairly
prominently in the Mike spectrum. It is interesting to note that NO, does not appear measurable in Tumbler-Snapper 3 or loom prominently in Tumbler-Snapper 3. A value of about 4 mm
at STP has been roughly calculated for NO, in Tumbler-Snapper 7, and a value probably not
too much in excess of this holds for Mike.
4.6.3 Ionized Nitrogen
At present there is no explanation for gre spectral behavior of Nj. It is not easy-to observe
its presence in Mike, but in King (total) it 1s quite evident, as it is in Tumbler-Snapper 3. In
the early-time shots, its presence in Tumbler-Snapper 7 and its absence in Buster Charlie
are noteworthy. In Tumbler-Snapper 7 it is only the 3914 A band which appears; this is the
0-0 band due to a transition in which the molecule is initially in the vibrationless groundstate.
This points to a correspondingly low vibrational temperature. The rotational temperature for
the same band was roughly calculated to be 4000°K, and in view of this high rotational temperature, it is hard to understand why the 1-0 transition band at 4278 A is not also in TumbierSapper 7. This behavior differs from that of early O, for the same plate. The O, rotational
temperature was only about 400°K, and yet so many high vibrational states are present.
Table 4.6 shows for the 4278 A band that there is a greater NJ production in King (total)
than in Tumbler-Snapper 2 (total). The 3914 A band occurs in both of these spectra also, but
overlappings prevented intensity measurementsof any value. It is difficult to say whether the
¢
rotational temperature for the NJ shown in King (total) is higher than in Tumbler-Snapper 7.
lis interesting that in the early first-maximum exposure for King the Nf does not definitely
‘pear. The foregoing statements give the observations, and, for lack of more detailed data,
% explanation can be given here.
4.6.4
Tron
The appearance of iron is noted very briefly in Table 1.1 as well as in the composite
Wavelength table (Appendix A). Its presence or absence and its approximate cutoff value are
Given. The cutoff is an interesting and currently inexplicable phenomenon. It may be due to
Sperposition in time of many spectra to give a cutoff effect.
{7 SUMMARY
There is a Marked difference between early or first-maximum exposures and later or
tae exposures. The first-maximum spectrum in the 3000 to 4500 A region is consid-
¥ simpler than that.of the second maximum since no casing material shows and the S-R
tt fewer rotational lines.
Tables be considered in this report that four orders of magnitude of yield are being treated:
(to 000geaeper 2 (yield 1.17 kt), Tumbler-Snapper 3 (30.7 kt), King (540 kt), and Mike
my
kt), The main features are material observed, amounts of absorbing material, the
esff fr
Cquency, and temperatures. The spectra of these four shots plus that of Tumbler-
T 4 are summarized here.
Al
Tumbler-Snapper 2 (1.17 kt, Airdrop, Total Time)
It
Rent owes aluminum and barium in absorption, also AlO. Iron in absorption is very promi© whole range. In fact, the S-R spectrum of O, is masked by the presence of the
.
.
33