We show a drastically improved gas–solid reaction between NH3 and LiH by mechanical treatment for LiH, generating a hydrogen gas even at room temperature. The results of x-ray photoelectron spectroscopy showed that the mechanical pretreatment was effective in reducing a hydroxide phase from the surface of LiH. It was also possible to successfully recycle back LiNH2, which is the byproduct of this hydrogen desorption reaction, to LiH under 0.5-MPa H2 flow at 573 K. Thus, the LiH–NH3 system provides a recyclable H2 storage system to generate H2 at room temperature with 8.1 mass% and 4.5 kg/100 L hydrogen capacity.

In-situ observation of the reaction between light weight hydride LiH and NH3 gas was performed by means of TEM (Transmission Electron Microscopy) with an environmental cell. This environmental cell was designed for the observation of the gas-solid reaction under 0 ∼ 0.2 MPa gas atmosphere at 20 ∼ 150 °C. It has been confirmed a volume expansion and generation of LiNH2, that is the reaction between LiH and NH3. Moreover, it was revealed that LiNH2 was generated at the surface of LiH particle at first process of the reactions.

High-energy protons are generated by focusing an ultrashort pulsed high intensity laser at the Advanced Photon Research Center, JAERI-Kansai onto thin (thickness <10 μm) Tantalum targets. The laser intensities are about 4 × 1018 W/cm2. The prepulse level of the laser pulse is measured with combination of a PIN photo diode and a cross correlator and is less than 10−6. A quarter-wave plate is installed into the laser beam line to create circularly polarized pulses. Collimated high energy protons are observed with CH coated Tantalum targets irradiated with the circularly polarized laser pulses. The beam divergence of the generated proton beam is measured with a CR-39 track detector and is about 6 mrad.