A borehole muon detector for muon radiography or geotomography is provided, the borehole muon detector including a substantially cylindrical housing, which defines a bore, a pair of end caps, each end cap sealing an end of the cylindrical housing and a plurality of sealed drift tubes which are longitudinally disposed in the bore of the housing to form a bundle of drift tubes, wherein each sealed drift tube comprises: a centrally located anode wire disposed on a longitudinal axis; an inner surface which is coated with a cathode coating, the cathode coating divided into a first cathode pad and a second cathode pad by a Vernier pattern; and a timer in electrical communication with the anode wire for measuring a drift time. A system and a method are also provided.

A borehole muon detector for muon radiography or geotomography is provided, the borehole muon detector including a substantially cylindrical housing, which defines a bore, a pair of end caps, each end cap sealing an end of the cylindrical housing and a plurality of sealed drift tubes which are longitudinally disposed in the bore of the housing to form a bundle of drift tubes, wherein each sealed drift tube comprises: a centrally located anode wire disposed on a longitudinal axis; an inner surface which is coated with a cathode coating, the cathode coating divided into a first cathode pad and a second cathode pad by a Vernier pattern; and a timer in electrical communication with the anode wire for measuring a drift time. A system and a method are also provided.

Proposed are non-invasive diagnostic method and apparatus for plasma processes in which plasma processes can be monitored in real time by measuring a surface wave resonance frequency generated in plasma or a sheath on the basis of a surface wave resonance principle. The diagnostic method may include a step (S10) of installing at least one probe on one side of an electrostatic chuck (ESC) or on an inner wall of a chamber, a step (S20) of emitting a high frequency onto the plasma or the sheath by the probe, and a step (S30) of detecting a frequency reflected from the plasma or the sheath by the probe. In addition, the diagnostic method may include the step (S40) of extracting a reflection spectrum, a step (S50) of extracting the surface wave resonance frequency, and a step (S60) of extracting electron density or uniformity of the plasma.