  The low energy (LE) X-ray telescope is one of the three main instruments of
the Insight-Hard X-ray Modulation Telescope (Insight-HXMT). It is equipped with
Swept Charge Device (SCD) sensor arrays with a total geometrical area of 384
cm2 and an energy band from 0.7 keV to 13 keV. In order to evaluate the
particle induced X-ray background and the cosmic X-ray background
simultaneously, LE adopts collimators to define four types of Field Of Views
(FOVs). LE is constituted of three detector boxes (LEDs) and an electric
control box (LEB) and achieves a good energy resolution of 140 eV at 5.9 keV,
an excellent time resolution of 0.98 ms, as well as an extremely low pileup
(<1% at 18000 cts/s). Detailed performance tests and calibration on the ground
have been performed, including energy-channel relation, energy response,
detection efficiency and time response.
