Muon detector for muon tomography

A system, comprising:

• a plurality of muon detectors, each sized and shaped for deployment down a borehole, each muon detector comprising a chamber, a gas sealed inside the chamber, the gas having a composition and pressure sufficient to be ionized by the passage of atmospheric muons through the chamber to form ions in the chamber, a micropattern gaseous detector arranged and configured to receive the ions or electrons formed in the chamber and generate electrons in response to each ion, an anode comprising a mesh of wires arranged to generate a current in one or more of the mesh wires in response to the generated electrons, and readout electronics in electrical communication with the anode and configured to detect signals in response to the current generated in the one or more of the mesh wires, the readout electronics comprising a charge sensitive amplifier connected to the anode, an amplifier/shaper configured to generate a Gaussian pulse and amplify the signal generated in each wire, and a comparator to provide a digital signal based on an amplitude of the Gaussian pulse and a preselected threshold,
• each muon detector being configured to provide data corresponding to a direction of propagation of muons passing through the chamber;
• and
• an electronic processing apparatus in communication with each of the muon detectors and programmed to receive the data, to calculate the direction of muons passing through each of the muon detectors, and to determine information about subterranean mineral deposits based on the direction of the muons and the location of each of the muon detectors when deployed down one or more boreholes.

A method, comprising:

• deploying a muon detector at a location underground, the muon detector comprising a gas sealed inside a chamber and a plurality of electrodes, a micropattern gaseous detector, and readout electronics;
• energizing the plurality of electrodes to cause ions or electrons resulting from a passage of an atmospheric muon through the gas to interact with the micropattern gaseous detector to generate electrons;
• detecting the generated electrons at an anode of the plurality of electrodes;
• generating signals at the anode in response to detecting the generated electrons;
• generating, using the readout electronics, digital signals from the signals generated at the anode, the readout electronics comprising a charge sensitive amplifier connected to the anode, an amplifier/shaper configured to generate a Gaussian pulse and amplify each signal generated by the anode, and a comparator to provide the digital signals based on an amplitude of the Gaussian pulse and a preselected threshold;
• receiving data from the muon detector based on the digital signals, the data comprising information about the passage of the atmospheric muon through the gas of the muon detector;
• and
• determining information about a subterranean mineral deposit based on a direction of the muon through the gas and the location of the muon detectors underground.