1. In surgery, a probe is a slender flexible rod with a blunt end used to explore; for example, an opening to see where it goes.
2. An exploratory action, expedition, or device, especially one designed to investigate and to obtain information about a remote or unknown region.
3. An investigation into unfamiliar matters or questionable activities; a penetrating inquiry: Mar conducted a congressional probe into price fixing.
4. A space probe or a rocket-propelled guided missile that can escape the earth's atmosphere and which makes observations of the solar system that cannot be made by terrestrial observations.

1. The act of exploring or searching with or as if with a device or instrument.
2. To delve into; to investigate.

A tool used to measure electron temperatures, electron and ion densities, space and wall potentials, and random electron currents in a plasma.

It consists substantially of one or two small collecting electrodes to which various potentials are applied, with the corresponding collection of currents being measured.

1. An instrument which focuses an accelerated beam of electrons to an extremely small point on the surface of a crystal specimen so it can be studied by the effects of the electron beam.
2. An X-ray machine in which electrons transmitted from a hot-filament source are accelerated electrostatically, then focused to an extremely small point on the surface of a specimen by an electromagnetic lens.

A nondestructive analysis of the specimen can then be made by measuring the back-scattered electrons, the specimen current, the resulting X-radiation, or any other resulting process.

3. A technique of analysis using the electron microscope based on spectral analysis of the scattered X-ray emission from the specimen induced by the electron beam.

By using this technique, it is possible to obtain quantitative data on, for example, the calcium concentration in different parts of a cell; however, it is necessary to use ultra thin frozen sections.

1. A technique for the analysis of a very small amount of material by bombarding it with a narrow beam of electrons and examining the resulting x-ray emission spectrum.
2. An analytical technique used to determine the nature of extremely small samples by forming the x-ray spectrum of the samples through excitation by a finely focused electron beam.
3. Identification and measurement of elements and their location based on the fact that x-rays emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration.

It is performed with an electron microscope fitted with an x-ray spectrometer, in a scanning or transmission mode.

A Geiger-Mueller is a counter in a watertight container, which is lowered into a borehole to log the intensity of the gamma rays produced by radioactive substances in traversed rock or across a thin section of stone.

A gamma-ray counter built into a watertight case small enough to be lowered into a borehole.

An instrument for microscopic chemical analysis, in which a beam of primary ions with an energy in the range 5-20 kilo-electron volts hit a small spot on the surface of a sample with high-energy particles, and positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer.