d
\(r =\frac{ mv }{ qB }=\frac{ p }{ qB } \quad \frac{ m _{\alpha}}{ m _{ p }}=4\)

\(\frac{ r _{ p }}{ r _{\alpha}}=\frac{ p _{ p }}{ q _{ p }} \frac{ q _{\alpha}}{ p _{\alpha}}=\frac{2}{1}\)

\(\frac{ p _{ p }}{ p _{\alpha}}=\frac{2 q _{ p }}{ q _{\alpha}}=2\left(\frac{1}{2}\right)\)

\(\frac{ p _{ p }}{ p _{\alpha}}=1\)

\(\frac{ K _{ p }}{ K _{\alpha}}=\frac{ p _{ p }^{2}}{ p _{\alpha}^{ p }} \frac{ m _{\alpha}}{ m _{ p }}=(1)\) (4)