34 37 # first data record, number of data records Reference: JPL Publication 94-26 Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling Evaluation Number 11 December 15, 1994 page 150 ff. CCl3F (CFC-11) + hv -> Products "Tables 39, 40 and 41 list the present recommendations for the cross sections of CCl4, CCl3F and CCl2F2, respectively. These data are given by the mean of the values reported by various groups, i.e., Hubrich et al. [713], Hubrich and Stuhl [712], Vanlaethem-Meuree et al. [1613, 1614], and Green and Wayne [594], as well as those referred to in earlier evaluations (CODATA [347]). Absorption cross sections for these species over the temperature range 295-210K have also been reported by Simon et al. [1425]. These results are in generally good agreement with the present recommendations. Expressions for the temperature dependence of the CCl3F and CCl2F2 cross sections are given at the bottom of Tables 40 and 41, respetively. These expressions are valid in the wavelength range of maximum solar photodissociation, i.e., about 190-210 nm, but may not exactly reproduce the experimental temperature dependences outside this wavelength range. However, J-value calculations should not be affected." sigma(T) = sigma(298) * exp[1E-04 (lambda-184.9)(T-298)] where sigma(298) = cross section at 298 K lambda : nm T : temperature, K Table 40. Absorption Cross Sections of CCl3F ------------------------------------------------------------------- lambda (nm) 1E20 sigma (cm^2) ------------------------------------------------------------------- 170 316 172 319 174 315 176 311 178 304 180 308 182 285 184 260 186 233 188 208 190 178 192 149 194 123 196 99 198 80.1 200 64.7 202 50.8 204 38.8 206 29.3 208 21.2 210 15.4 212 10.9 214 7.52 216 5.28 218 3.56 220 2.42 222 1.60 224 1.10 226 0.80 228 0.55 230 0.35 235 0.126 240 0.0464 245 0.0173 250 0.00661 255 0.00337 260 0.00147