I just calculated energy consumption for the following parameters:
• Deuterium – 450keV
• Tritium – 300keV
• Electron – 40.6MeV
And energy consumption specified per a single fusion event is about 1.8MeV
Taking into account that collision energy in center-of-mass frame for this case is 30keV (30keV vs. 20.2keV) and so ratio between fusion and scattering sections is more attractive, we should also wait less further energy losses that for previous case estimated as 0.7MeV per each event.