Developing and Characterizing X-ray Concentrators for Space-Based Observations with the Neutron Star Interior Composition Explorer
| dc.contributor.advisor | Hayden, Michael | |
| dc.contributor.author | Balsamo, Erin Rose | |
| dc.contributor.department | Physics | |
| dc.contributor.program | Physics, Applied | |
| dc.date.accessioned | 2019-10-11T14:03:20Z | |
| dc.date.available | 2019-10-11T14:03:20Z | |
| dc.date.issued | 2017-01-01 | |
| dc.description.abstract | A long standing need to resolve the equation of state (EOS) of neutron stars motivated the Neutron Star Interior Composition Explorer's (NICER) mission goals, including determining stellar radii to within +/-5%. This can be accomplished by observing the change in photon flux over time from pulsars (rotating neutron stars with a magnetic field) in the soft X-ray energy band (0.2-12.0 keV) using NICER's highly effective photon focusing system comprised of 56 X-ray concentrators (XRC). In this thesis, I prove the efficiency and functionally of the specialized fabrication process which allowed for the success of producing flight ready XRCs in a cost effective manner, which have been shown to exceed mission requirements through ground calibration. I have also conducted simulations of a challenging yet advantageous observation of the closest millisecond pulsar (MSP) which will provide astronomers with useful NICER data to further constrain the EOS. X-rays are focused by grazing incident reflection with incident angles on the order of a degree. The NICER optics were designed as singly-reflecting concentrators with a curved axial profile for improved photon concentration and a sturdy full shell structure for enhanced module stability. I assisted in developing a new substrate forming technique to accommodate these unique design elements. By analyzing hundreds of substrates' profiles post-forming, I found the profiles were copied, on average, to within 4.6%+/-3.7%, i.e. with >95% accuracy. My ground calibration results and this analysis has shown that the heat shrink tape method is reliable, repeatable, and could be used in future missions to increase production rate and performance. NICER's 6 arcminute field-of-view poses a challenge in resolving the energy spectra and light curves of the closest MSP, PSR J0437-4715, due to the bright nearby X-ray source, the Active Galactic Nucleus (AGN) RX J0437.4-4711, with an angular distance of 4.2 arcmintues from the pulsar. Since the optics function as concentrators, all image resolution is lost. However, due to the energy dependency of the XRC's point spread function (PSF), I have found that the best way to observe the MSP is to point the instrument 2.7 arcmintues off-axis from the pulsar, away from the AGN; the pulsar to AGN flux is maximized at this point. Within the simulations, I carefully consider the multi-dimensional instrument pointing statistics, calibrated XRC PSFs, and a current theory of neutron star emission processes. | |
| dc.genre | dissertations | |
| dc.identifier | doi:10.13016/m2us5d-hzlj | |
| dc.identifier.other | 11677 | |
| dc.identifier.uri | http://hdl.handle.net/11603/15743 | |
| dc.language | en | |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Theses and Dissertations Collection | |
| dc.relation.ispartof | UMBC Graduate School Collection | |
| dc.relation.ispartof | UMBC Student Collection | |
| dc.rights | This item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu | |
| dc.source | Original File Name: Balsamo_umbc_0434D_11677.pdf | |
| dc.subject | astrophysics | |
| dc.subject | neutron stars | |
| dc.subject | NICER | |
| dc.subject | pulsars | |
| dc.subject | X-ray optics | |
| dc.title | Developing and Characterizing X-ray Concentrators for Space-Based Observations with the Neutron Star Interior Composition Explorer | |
| dc.type | Text | |
| dcterms.accessRights | Distribution Rights granted to UMBC by the author. |