"Diffraction by helical structures"

Date:
1956-1957
Reference:
PP/CRI/H/2/17
Catalogue details

Licence: In copyright

Credit: "Diffraction by helical structures". Source: Wellcome Collection.

    27/98
    is its rotational average, then î Kt W , K *' JX (té) and inverting we have J <*> ^ K¿(r)* [\\ ( T °(™H which is the desired relation« bj \ It is too early to s-y whether (m) will prove to he useful» One can see in a general way that P^jr) curve will contain peaks at 2r if there is a concentration of density at the radius r in the helical projection. 33 Itis perhaps worthwhile noting that equation (3f) which is the basis of our derivation is a special case of the formula (set % and we might hope to usé tí« latter in the same way to obtain results involving Ì \, j £ rather than ( t ) ♦ Bnt we see at once that (3®) involves products of Bessel functions of different order and such terms occur only in the expression for the full^three- ; \ dimensional intensity# It thus appears that equation (3g/) represents all we can hope to learn from the cylindrically averaged intensity alone It sometimes happens that we have helical molecules or polymers