Neumayer Station III


      The German research station Neumayer III installed and operated by the Alfred-Wegener-Institut is located at the Antarctic shelf ice. The main research fields are geophysics, meteorology and air chemistry.
      In 2012 a muon counter experiment and a mini neutron monitor, identical to those on the "Polarstern", have been installed at Neumayer III to measure the rates of cosmic particles.

      Since the Earth's magnetosphere guides charged low energy particles to the poles, these areas are characterised by spectacular polar lights in the atmosphere and an increased particle rate at ground level.
      A significant part of the low energy particles originates from the Sun. Therefore it is interesting to search for a correlation of solar events and particle rate in both experiments. The variation of cosmic particle activity during the 11 year solar cycle can also be observed.

       
      Setup of the Muon Detector


        The experiment measures muons, which are decay products of particles generated by the interaction of primary cosmic particles with atoms of the atmosphere. The muons are detected using two scintillator plates similar to the CosMO Experiment. The setup consists of the following components (see the numbering at the photo).


          1. two scintillation counters mounted at a vertical distance of 40 cm,
          2. a DAQ card (originally designed and produced for the Fermilab QuarkNet experiment),
          3. a notebook on which a python script analyses and stores the data so that a packed data file can be transmitted to DESY per email once a day.

            The two 25x25 cm2 detectors are each read by two PMTs. Only if both PMTs in both scintillators show a signal at the same time, the event will be accepted as a traversing muon. This coincidence condition ensures the reduction of false signals.

             
            Setup of the Mini Neutron Monitor


              Neutron monitors measure the nuclear component of cosmic particles reaching the Earth's surface. The North-West University of Pochefstroom (South Africa) has developed a light, portable version consisting of the following components:
              • the neutron detector,
              • an electronics box for the data acquisition,
              • a notebook to control the settings for the data taking and for the data storage and transfer.

              A detailed description of neutron monitors and how they work is given in the glossary.

               
              Data Structure


                The data files contain the following variables: time, particle rates per hour of both detectors, atmospheric pressure and temperature. More details are given in the description of the dataset.

                 
                Possible Student Exercises


                • Investigate the dependency of the particle rate on weather conditions.
                • Compare the weather conditions of different years.
                • Search for strong solar eruptions, which can lead to a sudden increase of the particle rate.
                • Compare the particle rates with data of other experiments (neutron monitors, satellites) measuring the particle flux of the Sun.
                • Compare the data with the data taken with the muon detector and the mini neutron monitor at the "Polarstern".

                  Example Diagrams


                    At Cosmic@Web some example diagrams can be found using the Session-ID Neumayer.
                     

                    Particle Rate versus Time for Muon Detector and Neutron Monitor


                     

                    2D Diagram Particle Rate versus Air Pressure