332 



BELL SYSTEM TECHNICAL JOURNAL 



(n.b. 

 toward 



(31-4) 

 (22-3) 

 (31-5) 



(52-5) 



clockwise and counter-clockwise directions are as seen when looking 

 the — end of the axis of rotation) 



Distance from the Center 



Calculated Measured 



25°22' 25°22' 



25°17' 25°18' 



6°49' 6°18' 



rsv 



8°00' 



Difference 

 0' 



+1' 



-31' 

 +29' 



A zimuth 

 (counter-clockwise from +Pi) 



Error 



()' 



30' counter-clock- 

 wise about Pi 



? 



^-^ 



y N = UNIT NORMAL TO (31-'5) 



Fig 3.28 — Orientation of the (31.4) atomic plane in the NT plate 



Now, a small rotation of amount Ei counter-clockwise about Pi followed 

 by one of amount £2 counter-clockwise about P2 and a similar one £3 about 

 Pz is given to the first order approximation by the matrix: 



/I -^3 ^2 \ 



e = [ ez 1 -eA (3.48) 



\— ^2 ei 1 / 



Where e\ , ei and Cz are the sines of the rotation angles £1 , £2 , £3 • 



* This error is determined by averaging the "difference" values for the two planes. 



