In this paper we consider the scalar particle creation from the quantum scalar vacuum by suddenly expanding the spherical shell with Dirichlet boundary condition. Here, we present a different theoretical scheme where mechanical oscillations are avoided. It is seen that the total number of photons is almost $8\times 10^6$ for smallest $b$ value, 10 $nm$ and this value remains almost constant over a large values of $b$, up to 100 micron
