# Changeset 15a7577 in sasmodels

Ignore:
Timestamp:
Sep 7, 2018 10:38:31 AM (18 months ago)
Branches:
master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests
Children:
455aaa1
Parents:
917d975
Message:

update hollow_cylinder docs

File:
1 edited

### Legend:

Unmodified
 ree5fc99 r""" Definition ---------- This model provides the form factor, $P(q)$, for a monodisperse hollow right angle circular cylinder (rigid tube) where the form factor is normalized by the volume of the tube (i.e. not by the external volume). angle circular cylinder (rigid tube) where the The inside and outside of the hollow cylinder are assumed to have the same SLD and the form factor is thus normalized by the volume of the tube (i.e. not by the total cylinder volume). .. math:: P(q) = \text{scale} \left/V_\text{shell} + \text{background} where the averaging $\left<\ldots\right>$ is applied only for the 1D calculation. where the averaging $\left<\ldots\right>$ is applied only for the 1D calculation. If Intensity is given on an absolute scale, the scale factor here is the volume fraction of the shell.  This differs from the :ref:core-shell-cylinder in that, in that case, scale is the volume fraction of the entire cylinder (core+shell). The application might be for a bilayer which wraps into a hollow tube and the volume fraction of material is all in the shell, whereas the :ref:core-shell-cylinder model might be used for a cylindrical micelle where the tails in the core have a different SLD than the headgroups (in the shell) and the volume fraction of material comes fromm the whole cyclinder.  NOTE: the hollow_cylinder represents a tube whereas the core_shell_cylinder includes a shell layer covering the ends (end caps) as well. The inside and outside of the hollow cylinder are assumed have the same SLD. Definition ---------- The 1D scattering intensity is calculated in the following way (Guinier, 1955) * **Author:** NIST IGOR/DANSE **Date:** pre 2010 * **Last Modified by:** Richard Heenan **Date:** October 06, 2016 (reparametrised to use thickness, not outer radius) * **Last Reviewed by:** Richard Heenan **Date:** October 06, 2016 * **Last Modified by:** Paul Butler **Date:** September 06, 2018 (corrected VR calculation) * **Last Reviewed by:** Paul Butler **Date:** September 06, 2018 """