Reactor particle fueling is one of the issues that remain to be resolved in the development of a tokamak fusion reactor. One of the most promising concepts of reactor fueling is the injection of high-speed compact toroids (CTs). Compact toroid formation and acceleration at the Ring Accelerator Experiment (RACE) device at Lawrence Livermore National Laboratory has shown that CT plasmoid velocities sufficient for center fueling fusion reactors can be achieved by using coaxial accelerators. The Compact Toroid Fueler (CTF) will inject high-speed, dense spheromak plasmoids into the Tokamak de Varennes (TdeV) to examine the feasibility of this approach as a fueler for future reactors. Here, a conceptual design study of the particle fueler for TdeV is presented. The issues of CTF design that are considered are formation and relaxation of an axisymmetric CT, optimization of accelerator performance to improve injector electrical efficiency, separation of formation and acceleration phases to improve injector reproducibility, minimization of entrained impurities in the CT, and minimization of neutral gas load to the tokamak following CT fueling. The CTF injector will test theories on CT/tokamak interaction related to reactor fueling. Among the eventual physics questions addressed are the multiple-pulse requirements for future injectors, the bootstrap current enhancement factor, CT fuel confinement times, impurity effects, plasma heating, injector electrical efficiency, and the effect of gas load on the tokamak following CT injection.