Presents the experimental results of the study of the relativistic electron beam (REB) generated in a foilless diode and its transport at low pressure (10-5 torr-250 mtorr) in hydrogen gas. The typical beam parameters are 240 kV, 0.1-6 kA and pulse width (FWHM) from 10 to 65 ns. A mirror magnetic field has been used to minimise beam losses. It has been observed that the input beam parameters are functions of gas pressure, and a maximum peak beam current of 6 kA is observed at a pressure of 100 mtorr of hydrogen. The beam current and its width decrease as the gas pressure is increased. The amplification of the net current over the input beam current is observed for propagation distances of Z=2 cm and Z=15 cm. The ratio of peak transmitted current to the peak input current increases as the pressure is increased and at a distance of Z=6 cm, there is an amplification of the peak beam transmitted current by a factor of 1.4 at a pressure of 200 mtorr. The analysis of the results shows that two stream instability may be operative in the pressure range studied and that there is also a possibility of formation of potential well and collective acceleration of ions.