Recently, pre-ionization experiments using thermal electron emission from LaB6 cathode and electron heating by 2 kW@14.5 GHz Klystron installed at cusp and plug cell respectively have been carried out in Hanbit mirror device. Charge exchange collision between ion and neutral atom has been concerned as an important mechanism of ion energy loss in the Hanbit discharges, hence the high pressure of neutral particles is one of the most reasonable cause of low ion temperature. In this work, we investigate low pressure operation mode with help of the pre-ionization to enhance the ion temperature. The ion temperature and temperature anisotropy are measured and also inferred by ELA(End Loss Analyzer) for central cell plasma. We also characterize RF heating properties for different regimes of /c0i using simulation code for electromagnetic waves.