336 H - NAGAOKA; DIFFEACTIOX PBENOMEXA 



Arranging the integrals in a suitable way and writing' 



1 



0.60984 3731 . 0.6162 



— arc sin-?r- = 



■K 2(2 



+ 



log tg 



y- arc sin q^= log a\— log Aa 



gf 3 a?! 4 



48a 2_ 128Ö* 



we find, for the intensity at the rim of a circular di.sc, whose radius is 

 large compared to x Y 



T 1 loa 4a 0.1654 1 ^ rk1 „ cos 4a , / T \r>* 



Jh=-ö- 2 hO.016 j— nearly. (IN) 



As w r as before remarked, the intensity at the rim approaches -5- 

 with increasing values of a ; it is moreover seen how the fluctuation 

 due to the term cos 4a is negligibly small. By applying the above 

 formula, the following table was calculated for a>20. 



