we EE ah aba ee wat Dee als ea alla Eade ine 218 im qT 0.12 7 Hest Ne + 0.11 f— M2/C | Ary No. He(He) wis 0.10 _ He + HoT No CHa + BFy, CaNo +.PHs ' + kycatt H 2 10 | 18 4-3 iCa tio xe 4-2 +%ers cyCgHiz, ,NCgHis ++ C5H + nCgHi2 6 CO2 4 4{CHs}20 CH30H +? nCeHio ++ CeHsOH (cH4)0C0 + 0.09 rT Kr neoCa hyo 4thC2He CoH, T + CsHg 0 402 co 4 CF4 In ¢j 44 - \ nCrHig C/M? - in cj = In (2/a)* aL 26 Lt 36 42 ° ee 48 54 58 n = TOTAL NUMBER OF ELECTRONS Fic. 169.—Experimental results for M2/C of 0.01. Points of that or better accuracy are given unit weight in the LS solution; points of less accuracy are given appropriately smaller weight. In some cases, the RAIS deviation turns out to be very nearly 0.01; in others, us much as 215 times as great. The difference cannot be attributed to genuinely randomeffects; we attribute it to variations in e, which have been treated as systematic crror. We conclude that the true random error in our experiments can be estimated reasonably well by multiplying the cocfficients from the LS solution by 0.01. It is the random error so obtained that should be added to the systematic errors indicated in Table 79. The coefficients vary from experiment to experiment, since they depend upon the number and distribution of the data points. They lead to magnitudes of AC/C ranging from 0.002 to 0.012. For A(Af?/C), the magnitudes range from 0.0015 to 0.004. SUMMARY All the results obtained to date are summarized graphically in Figures 168 and 169. With the aid of values taken from these plots and Figure 166, cross sections at any energy where the Bethe formula is applicable can be obtained by simple multiplication. REFERENCE 1. Rieke, F. F. and Prepejchae, William. Argonne National Laboratory Radiological Physics Division Annual Report, July 1967-June 1968. ANL-7489, p. 99. TABLES OF ABSORPTION CROSS SECTIONS, PHOTOIONIZATION YIELDS, AND PHOTOIONIZATION CROSS SECTIONS FOR SEVERAL GASES J.C. Person and P,P. Nicole Tables of absorption cross sections, photoionization yields, and photoionization cross sections are presented for acetylene, propyne, propene, methanol, ethanol, and methyl bromide, and also for the perdeuterated analogues of these gases. For each gas. the data are reported for energies ranging from a value belowthe ionization potential up to 1L.78 eV. This report gives the data in tabular form forresults that will be presented and discussed’ elsewhere. The data were collected using an experimental apparatus and procedure that were essentially the same as previ- ously described." ?) The data for acetylene, propyne, propene, methanol, ethanol, and methyl bromide are labelled with a subscript H; while the data for the per- deuterated analogues of these gases are labelled with a subscript D. Each table gives the wavelength and the energy, #, of the monochromatic (~1 A bandwidth) exciting light. The absorption cross sections, 7, were determined from measurements using ” gas pressures; and the deviations from a weighted least squares fit of the data to Beer’s law were used to estimate the 90% confidence limits as {¢ — 6c) to (o + éc). In addition to this statistical error, the systematie error in the ¢