  NaCl is a diatomic molecule with a large dipole moment, which allows for its
detection even at relatively small abundances. It has been detected towards
several evolved stars, among which is the AGB star IK Tau, around which it is
distributed in several clumps that lie off-center from the star. We aim to
study the three-dimensional distribution of NaCl around the AGB star IK Tau,
and to obtain the abundance of NaCl relative to H$_2$ for each of the clumps.
First, a new value for the maximum expansion velocity is determined. The
observed ALMA channel maps are then deprojected to create a three-dimensional
model of the distribution of NaCl. This model is then used as input for the
radiative transfer modelling code magritte, which is used to obtain the NaCl
abundances of each of the clumps by comparing the observations with the results
of the magritte simulations. Additionally, the rotational temperature of the
clumps is determined using population diagrams. We derive an updated value for
the maximum expansion velocity of IK Tau $\upsilon_\mathrm{exp}$ = 28.4 km/s. A
spiral-like shape can be discerned in our three-dimensional distribution model
of the NaCl. This spiral lies more or less in the plane of the sky. The
distribution is also flatter in the line-of-sight direction than in the plane
of the sky. We find clump abundances between $9 \times 10^{-9}$ and $5 \times
10^{-8}$ relative to H$_2$, where the relative abundance is typically lower for
clumps closer to the star. For the first time, we used deprojection to
understand the three-dimensional environment of an AGB star and calculated the
fractional abundance of NaCl in clumps surrounding the star.
