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# Chudley-Elliot¶

## Description¶

Models the Q dependence of the QENS line width (Gamma (hwhm)), diffusion coefficients (D), residence times (tau) and jump lengths (length) to extract the associated long range diffusive motions of molecules.

The Chudley-Elliot Jump diffusion model [1] has the form:

$HWHM(Q) = \frac{\hbar}{\tau} \cdot \left(1 - \frac{sin(Ql)}{Ql}\right)$

Units of $$l$$ are inverse units of $$Q$$.

Units of $$HWHM$$ are $$meV$$ if units of $$\tau$$ are ps. Alternatively, units of $$HWHM$$ are $$\mu eV$$ if units of $$\tau$$ are ns.

Name

Default

Description

Tau

1.0

Residence time

L

1.5

Jump length

## References¶

Categories: FitFunctions | QuasiElastic

## Source¶

Python: ChudleyElliot.py