The detent force of a permanent magnet linear synchronous motor (PMLSM) consists of cogging and drag forces, and should be minimized for high precision purpose application. This paper suggests a new 9-pole 10-slot structure of a short primary PMLSM to remove the cogging force. Through theoretical and finite element analysis, the proposed structure is proven to remove most of the cogging force. The detent force is minimized by optimizing the length of armature core and shape of the exterior teeth simultaneously by using (1+lambda) evolution strategy coupled with response surface method using multi-quadric radial basis function. Additionally, simulation results for the proposed structures are verified by experimental measurements.