Abstract
In this work, we study an inverse problem to determine an unknown source term for fractional diffusion equation with Riemann–Liouville derivative. In general, the problem is severely ill posed in the sense of Hadamard. To regularize the unstable solution of the problem, we have applied the quasi-boundary value method. In the theoretical result, we show the error estimate between the exact solution and regularized solution with a priori parameter choice rules and analyze it. Eventually, a numerical example has been carried out, the result shows that our regularization method is converged.