This paper presents the first application of a symmetric interior-penalty discontinuous Galerkin
isogeometric analysis (SIP-DG-IGA) spatial discretization to the self-adjoint angular flux (SAAF)
form of the multi-group neutron transport equation. The penalty parameters are determined, for
general element types, from a mathematically rigorous coercivity analysis of the bilinear form.
The proposed scheme produces a compact spatial discretization stencil. It also yields symmetric
positive-definite (SPD) matrices, which can be efficiently solved using pre-conditioned conjugate
gradient (PCG) solution algorithms. The proposed discretization scheme is verified using the
method of manufactured solutions (MMS) and several nuclear reactor physics benchmark verification test cases. For sufficiently smooth elliptic problems, the proposed spatial discretization
can exploit higher-order continuity, or 𝑘-refinement, of the NURBS basis to consistently yield
greater numerical accuracy per degree of freedom (DoF) than standard ℎ-refinement. Since this
is a discontinuous scheme, it can also accurately model significant changes in the neutron scalar
flux that may occur near the material interfaces of heterogeneous problems.