Scattering parameters (choice of incident radiation from CO2 sources through far-infra-red (FIR) and millimetre sources, forward scattering and orientation angles) are sought so that the one-dimensional alpha particle distribution can be deduced directly from the experimental data. This deduction can be optimized by using orientations with incident FIR and millimetre radiation at forward scattering angles θ. Backscattering angles can be used for longer wavelength millimetre sources, although the deduction will be more difficult than for θ < 90°. The use of CO2 scattering will be very difficult.