  Recently, iterative Quasi-Monte Carlo (iQMC) was introduced as a new method
of neutron transport which combines deterministic iterative methods and
quasi-Monte Carlo simulation for more efficient solutions to the neutron
transport equation. Previous iQMC results utilized a uniform Cartesian grid
with a piecewise-constant source. Similar to "teleportation error" in Implicit
Monte Carlo (IMC) methods, the spatial discretization and piecewise-constant
source can lead to a significant spatial error that limits convergence of the
overall method. Taking concepts from IMC, we have developed a history-based
discontinuous piecewise-linear source tilting scheme to reduce spatial error in
iQMC. The source tilting method is described below and afterward we present
results from a fixed-source 2D reactor-like problem adapted from the Takeda-1
Benchmark problem.
