MINOS is a Neutrino Oscillation Experiment that uses the NuMI neutrino beam at Fermilab and two magnetic detectors, one at Fermilab, 980 ton, at 1 Km from the neutrino target and a large one, 5400 ton, at 735 Km, 2400 feet underground in the Soudan mine in northern Minnesota. The main goals of the experiment are: 1) To observe  muon neutrino disappearance and measure precisely the neutrino mass splittings by comparing the neutrino energy spectra in the near and far detector. 2) To search for muon neutrino to electron neutrino appearance and make a possible first measurement of  q13. 3) Measure neutrino disappearance for muon neutrinos and also anti-neutrinos to test CPT symmetry with neutrinos.

The MINOS Far Detector is a 5.4 kton magnetized Fe/Scintillator calorimeter and muon spectrometer, made of alternating octagonal planes of 1 inch thick steel , 8m x 8m transversely and scintillator planes made with scintillator strips with WLS fiber readout  and Hamamatsu M16 multi-anode photomultipliers. It consists of two supermodules with a total of 484 planes of scintillator and 486 planes of steel. Electronics: Hamamatsu M16 MAPMTs with V-A chip readout. The role of the MINOS Far Detector is to search for neutrino oscillations.

The MINOS Near Detector is a 1 kton version of the Far Detector with veto, target, shower and muon spectrometer sections.  It has Fe/Scintillator planes of a squeezed octagon shape with dimensions 3.8m x 4.8m. It has 282 steel planes and 153 scintillator planes. It uses fast front end electronics based on the QIE chip. The role of the MINOS Near Detector is to measure the neutrino flux near the neutrino source and use this information to predict the unoscillated neutrino energy spectrum at the location of the Far Detector.  Several neutrino interactions are recorded per beam spill in the Near Detector, allowing high statistics physics studies.

One of the two magnetic horns used in the NuMI beam. The NuMI  beam uses 120GeV protons from the Fermilab Main Injector with a repetition cycle of about 2 seconds and an intensity currently of about 2.5 E+13 protons per pulse. It uses single turn (10 us) extraction. The beam impacts on a 95.4 cm graphite target followed by a pair of parabolic horns, with a pulsed current of 200 kA.  The position of the target second horn can be varied to produce neutrino beams of variable tunes: Low , Medium, and  High Energy.  Currently we run with LE neutrino beam with peak energy at about 3 GeV.