# Core Multi Shell

## Description:

Definition

This model is a trivial extension of the CoreShell function to a larger number of shells. The scattering length density profile for the default sld values (w/ 4 shells).

SLD profile of the core_multi_shell object from the center of sphere out for the default SLDs.*

The 2D scattering intensity is the same as $P(q)$ above, regardless of the orientation of the $\vec q$ vector which is defined as

$$q = \sqrt{q_x^2 + q_y^2}$$
.. note:: **Be careful!** The SLDs and scale can be highly correlated. Hold as many of these parameters fixed as possible.

.. note:: The outer most radius (= *radius* + *thickness*) is used as the effective radius for $S(Q)$ when $P(Q)*S(Q)$ is applied.

For information about polarised and magnetic scattering, see the `magnetism` documentation.

by the NIST Center for Neutron Research (Kline, 200_.
Our model uses the form factor calculations implemented in a c-library provided

References

See the `core-shell-sphere` model documentation.
S R Kline, *J Appl. Cryst.*, 39 (2006) 895
L A Feigin and D I Svergun, *Structure Analysis by Small-Angle X-Ray and
Neutron Scattering*, Plenum Press, New York, 1987.

Authorship and Verification

**Author:** NIST IGOR/DANSE **Date:** pre 2010