helical ribbon

[Claudio Ferrero]

Dear All,

could somebody help me in finding out the expression of the form factor
P(q) of an object with the shape of a helical ribbon ?

Many thanks in advance for your kind answers

Caudio Ferrero
*---------------------------------------*-----------------------------------*
|                                       |                                   |
|Dr. Claudio Ferrero                    |  _    _     _     _  /\           |
|Head of the                            | |_   |_    |_|   |_ /**\    /\    |
|Scientific Software Service            | |_    _|   |\    | /****\  /**\   |
|European Synchrotron Radiation Facility|             /\    /****  \/ ***\  |
|Boite Postale 220                      |        /\  /**\  /***    /   ***\ |
|F - 38043 Grenoble cedex               |       /**\/*** \/       /        \|
|France                                 |      /*  _______\______/__________|
|                                       |         /_________________________|
|Direct Line: +33 (0)4 76 88 23 70      |           |_|_|_|_|_|_|_|_|_|_|_|_|
|Fax:         +33 (0)4 76 88 25 42      |           |_______________________|
|                                       |           |_|_|_|_|_|_|_|_|_|_|_|_|
|Email:        ferrero at esrf.fr          |           |_______________________|
|                                       |                                   |
*---------------------------------------*-----------------------------------*