Performance analysis of the intense slow-positron beam at the NC State University PULSTAR reactor
| Autor: | E.W. Bodnaruk, J. Moxom, Jun Xu, A.G. Hathaway, Ayman I. Hawari |
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| Rok vydání: | 2007 |
| Předmět: |
Physics
Nuclear and High Energy Physics Range (particle radiation) Electronvolt chemistry.chemical_element Nuclear reactor Tungsten law.invention Nuclear physics Positron chemistry law Physics::Accelerator Physics Atomic physics Instrumentation Intensity (heat transfer) Electrostatic lens Beam (structure) |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 579:534-537 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2007.04.117 |
| Popis: | An intense positron beam, for application in nanophase characterization, is now under construction at the 1 MW PULSTAR nuclear reactor at North Carolina State University (NCSU). A tungsten converter/moderator is used, allowing positrons to be emitted from the surface with energies of a few electron volts. These slow positrons will be extracted from the moderator and formed into a beam by electrostatic lenses and then injected into a solenoidal magnetic field for transport to one of three experimental stations, via a beam switch. To optimize the performance of the beam and to predict the slow-positron intensity, a series of simulations were performed. A specialized Monte-Carlo routine was integrated into the charged-particle transport calculations to allow accounting for the probabilities of positron re-emission and backscattering from multiple-bank moderator/converter configurations. The results indicate that either a two-bank or a four-bank tungsten moderator/converter system is preferred for the final beam design. The predicted slow-positron beam intensities range from nearly 7×108 to 9×108e+/s for the two-bank and the four-bank systems, respectively. |
| Databáze: | OpenAIRE |
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