  The Low Energy X-ray Telescope is a main payload on the Hard X-ray Modulation
Telescope satellite. The swept charge device is selected for the Low Energy
X-ray Telescope. As swept charge devices are sensitive to proton irradiation,
irradiation test was carried out on the HI-13 accelerator at the China
Institute of Atomic Energy. The beam energy was measured to be 10 MeV at the
SCD. The proton fluence delivered to the SCD was
$3\times10^{8}\mathrm{protons}/\mathrm{cm}^{2}$ over two hours. It is concluded
that the proton irradiation affects both the dark current and the charge
transfer inefficiency of the SCD through comparing the performance both before
and after the irradiation. The energy resolution of the proton-irradiated SCD
is 212<EMAIL_ADDRESS>keV at $-60\,^{\circ}\mathrm{C}$, while it before irradiated is
134 eV. Moreover, better performance can be reached by lowering the operating
temperature of the SCD on orbit.
