Abstract: It is intended to realize measuring of trace organic components and to render qualitative procedure efficient through imparting of selectivity. Penning gas and dopant gas are ionized in a space isolated from discharge part with the use of metastable helium obtained by direct-current glow discharge, and with the use of thus obtained plasma, the efficiency of ionization of components to be measured is enhanced, so that intensified ion current can be obtained. Further, through selection of dopant gas and Penning gas, selectivity can be imparted. Thus, not only can measuring of trace organic components be performed but also selectivity can be imparted.

Abstract: An operational amplifier and a scanning electron microscope which are capable of dealing with high voltage and large current, and which allow implementation of stable and precise amplification, the operational amplifier having a first-stage amplification unit including a differential pair, a base-grounded amplification circuit, and an active load, the base-grounded amplification circuit being cascode-connected to the differential pair a second-stage amplification unit including an inverter having an emitter follower circuit and a constant-current load circuit, and a third-stage amplification unit including a source follower circuit or an emitter follower circuit.

Abstract: It is intended to realize measuring of trace organic components and to render qualitative procedure efficient through imparting of selectivity. Penning gas and dopant gas are ionized in a space isolated from discharge part with the use of metastable helium obtained by direct-current glow discharge, and with the use of thus obtained plasma, the efficiency of ionization of components to be measured is enhanced, so that intensified ion current can be obtained. Further, through selection of dopant gas and Penning gas, selectivity can be imparted. Thus, not only can measuring of trace organic components be performed but also selectivity can be imparted.