  The imaging performance and sensitivity of an X-ray telescope when observing
astrophysical sources are primarily governed by the optical design, geometrical
uncertainties (figure errors, surface roughness, and mirror alignment
inaccuracies), and the reflectivity properties of the X-ray reflecting mirror
surface. To thoroughly evaluate the imaging performance of an X-ray telescope
with an optical design similar to Wolter-1 optics, which comprises multiple
shells with known geometrical uncertainties and mirror reflectivity properties,
appropriate computational tools are essential. These tools are used to estimate
the angular resolution and effective area for various source energies and
locations and, more importantly, to assess the impact of figure errors on the
telescope's imaging performance. Additionally, they can also be used to
optimize optics geometry by modifying it in reference to the Wolter-1 optics,
aiming to minimize the optical aberration associated with the Wolter-1
configuration. In this paper, we introduce DarsakX, a Python-based ray tracing
computational tool specifically designed to estimate the imaging performance of
a multi-shell X-ray telescope. DarsakX has the capability to simulate the
impact of figure errors present in the axial direction of a mirror shell. The
geometrical shape of the mirror shells can be defined as a combination of
figure error with the base optics, such as Wolter-1 or Conical optics.
Additionally, DarsakX allows the exploration of new optical designs involving
two reflections similar to Wolter-1 optics but with an improved angular
resolution for wide-field telescopes. Developed through an analytical approach,
DarsakX ensures computational efficiency, enabling fast processing.
