Rotary pulse generator

In the GM-type PTR (mostly used at present), a compressor produces continuous high and low pressures and uses a rotary valve to generate pressure oscillations in the pulse tube. In the Stirling-type PTR, pressure oscillations are created by the movement of a piston, directly connected to the pulse tube and controlled by a motor. 

Fig. 2.17. Side elevation of the vacuum setup of the molecular beam machine. Chi vacuum chamber to generate the molecular beam by adiabatic expansion. The oven shown in Fig. 2.19 is inside. Ch2 vacuum chamber where the molecules interact with the laser pulses and are detected by a quadrupole mass spectrometer (QMS) or a Langmuir-Taylor detector (Fig. 2.22). Chi is pumped by an oil diffusion pump (DP) with a cold trap (CT), Ch2 by a turbomolecular pump (TP). Prevacuum is provided by a Roots (RVP) and a rotary valve vacuum pump (RVVP)...

---