I have a question regarding shockwaves. So as far as my knowledge, a flow moving at Ma= 1 will create a normal shockwave ($arcsin(1/Ma)$) , and a flow moving faster will cause an oblique shockwave. So can a normal shockwave occur if the flow is diverged with angle Beta, if it was close to speed of sound?
It appears you have a slight misunderstanding with regard to the formation of normal shock wave when a flow moves at Ma = 1. It is not so, when a flow moves at Ma = 1, very weak oblique shock waves called Mach waves are formed at an angle $arcsin(1/Ma)$. Oblique shock wave is formed (not normal shock wave) when the flow is diverted by an angle $\beta$ when greater then the speed of sound.