Research

The NMU Physics faculty participates in a lot of different research. Some of the projects that they are currently working on are explained below:

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Research Results Published of Experiments Measuring the Target Spin Asymmetries for Helium-3 (He-3)

Professor William Tireman (Physics) and Bradley Schoenrock (NMU 2010) in collaboration with the Hall A Collaboration at Jefferson National Laboratory in Newport News, VA have recently published data from a 2009 experiment designed to measure the target spin asymmetries for Helium-3 (He-3).  These results extend the currently available data and significantly increase the data precision.  This is necessary to continue the refinement of the physics models of the structure of the

He-3 nucleus which is made of 2 protons and 1 neutron.  One of the primary uses of He-3 is in the study of the internal structure of neutrons.  Free neutron targets are not possible so composite nuclear systems such as the deuteron (H-2) and Helium-3 (He-3) are used instead.

However, to extract the desired information from the scattering data it is necessary to have a highly precision model of this nuclear system. 

The results are published in PRL (2014).  http://arxiv.org/abs/1409.2253

 

Dr. Tireman and Collaborators Publish Results of Nucleon-Nucleon Experiment

Dr. Tireman in collaboration with the E07-006 collaboration at Thomas Jefferson National Laboratory (JLab) in Newport News, VA has completed an experiment designed to study the nucleon-nucleon short range repulsive core.  The collaboration, which includes 118 scientists from 49 instructions, measured the nucleon-nucleon short-range colleration to deduce the isospin structure in the region in which the nuclear force is expected to change from a tensor force to a repulsive force.  Some of the neutron detectors used in the experiment were assembled by former NMU student Brad Schoenrock.  Data for this experiment was collected in 2011 and analysis was completed recently.  The paper has been submitted to PRL for publication. Link to abstract

What the detectors looked like originally

Neutron Detector Polishing and Assembly

Dr. Will Tireman has several students working on the polishing and assembly of large volume plastic scintillation detectors which will be used as neutron detectors for an experiment to be ran at Jefferson National Laboratory (JLab) in Newport News, Virginia. The experiment is led by a group from Kent State University (Dr. Tireman’s alma mater) and will be investigating the internal charge distribution of the neutron at low energy transfers via a polarized electron-neutron collision.

In this experiment the electron is the projectile and the neutron is the fixed target. The goal of the experiment is to decrease the experimental uncertainties at this energy by more than one-half and thereby result in a stronger test for theoretical nuclear models.

Once the students have finished the polishing of the 18 rectangular parallelepipeds (volume of 100 cm by 25 cm by 10 cm and weighing approximately 65 pounds) they will attach an acrylic light guide to each end of the scintillator. Each light guide requires polishing as well. The entire detector will then be wrapped with a layer of white paper and then black electrical tape to seal the detector from external light. Photomultiplier tubes will be mounted to the ends of the light guides and wrapped for light tightness as well.

Once that is completed, each detector will be tested for light leaks, carefully crated, and then sent to JLab where they will be part of a larger neutron detector package consisting of more than 200 neutron detectors of various sizes.

It is hoped that the NMU contribution will be completed by August and the experiment will run as scheduled in early 2009.

Polishing the detectors

Shaping the end caps

 

Taped and ready to be shipped!

 

 

CPT and Lorentz Symmetry; The Standard-Model Extension

Dr Neil Russell does theoretical research focusing on testing the theory of relativity. The tool for this is the Standard-Model Extension, or SME, a framework that incorporates a variety of minuscule relativity 'violations.' The effects of these violations, if they exist, are measurable in sufficiently sensitive experiments. His recent research involves using the SME to figure out the signals that arise in various experimental systems. He has also worked on other theoretical topics, including quantum-mechanical supersymmetry and superalgebras.

For Dr Russell's research page, see:

http://physics3.nmu.edu/~nrussell/research/research.htm

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