The minimum frequency of photon required to break a particle of mass 15.348 amu into $4 \alpha$ particles is
$\_\_\_\_$ kHz.
[mass of He nucleus = 4.002 amu, lamu $=1.66 \times 10^{-27} \mathrm{~kg}, \mathrm{~h}=6.6 \times 10^{-34} \mathrm{~J} . \mathrm{s}$ and $\mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}$ ]