where a is the typical pore size and rho is called the surface relaxivity. The latter is a material constant.
It is also shown that this result will hold for a whole porous material with a broad pore size distribution. In that case, the magnetization is described as the sum of all individual decaying pores: An Inverse Laplace transform, which can be performed numerically, yields the relaxation-time distribution which can be transformed into a pore-size distribution using the above shown equation.
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