Measurement of electron drift velocities and Lorentz angles in fast gas mixtures

Electron drift velocities and Lorentz angles have been measured in various fast gas mixtures: ArCH4, ArC2H6, CO2CF4, ARCO2CF4, and also in pure CH4, C2H6, CF4, and CO2. The measurements were carried out in crossed magnetic and electric fields using a new experimental method based on the detection of α-decay recoils in coincidence with α-particles. The magnitude of the B and E fields could be varied up to B = 1.4T and E = 6.5 kV/cm. The precision in the absolute measurements of the drift velocities was about 1%, and the Lorentz angles were measured with an accuracy of about 0.5°.