Zacarias, Sabrina (2022)
Probing nuclear density tails with antiprotons at PUMA: Detection and method.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00022851
Dissertation, Erstveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
Low-energy antiprotons can be used as a probe to study the proton and neutron content of the nuclear density tail. Towards the neutron drip line, this region is characterized by the development of neutron skins and the emergence of halos.
As of today, there is no facility that can provide a low-energy antiproton-radioactive ion collider. At CERN (Switzerland), however, the existence of both a Radioactive Ion Beam facility (ISOLDE) and a facility to produce antiprotons (the Antimatter Factory) provides a feasible ground to generate these interactions.
The antiProton Unstable Matter Annihilation experiment (PUMA) aims at transporting 10e9 antiprotons from the Antimatter Factory to ISOLDE to study the nuclear density tail by measuring the neutron-to-proton annihilation ratio of both stable and short-lived nuclei.
In this work, the development of the Time Projection Chamber (TPC), main detection component of the charged annihilation products, is presented. As the detector aims at being inserted into the bore of the 4 T solenoid of PUMA, a compact and low-maintenance device is required. The geometrical design was based on Monte-Carlo simulations optimized for detection efficiency and charge identification. The electrical design was also optimized to provide an homogeneous electric field in the drift region of the detector. Finally, the mechanical design was performed.
The sensitivity of the method used at PUMA is investigated with an atomic cascade code applied to antiprotonic tin and calcium atoms to study the impact of the unknown capture states. Benchmarks of the code with X-ray data provide an initial estimation of the capture parameters and the cascade calculations show that 70% of the annihilations occur at the circular states (n, l = n−1), validating the PUMA concept. The isotopic sensitivity of the annihilation width ratio obtained from the measurement is quantified. Additional theoretical developments that describe the full capture and cascade are needed to account for the impact of low-l annihilations which are here observed to be non-negligible.
| Typ des Eintrags: | Dissertation | ||||
|---|---|---|---|---|---|
| Erschienen: | 2022 | ||||
| Autor(en): | Zacarias, Sabrina | ||||
| Art des Eintrags: | Erstveröffentlichung | ||||
| Titel: | Probing nuclear density tails with antiprotons at PUMA: Detection and method | ||||
| Sprache: | Englisch | ||||
| Referenten: | Obertelli, Prof. Dr. Alexandre ; Nörtershäuser, Prof. Dr. Wilfried | ||||
| Publikationsjahr: | 2022 | ||||
| Ort: | Darmstadt | ||||
| Kollation: | xxi, 114 Seiten | ||||
| Datum der mündlichen Prüfung: | 26 Oktober 2022 | ||||
| DOI: | 10.26083/tuprints-00022851 | ||||
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/22851 | ||||
| Kurzbeschreibung (Abstract): | Low-energy antiprotons can be used as a probe to study the proton and neutron content of the nuclear density tail. Towards the neutron drip line, this region is characterized by the development of neutron skins and the emergence of halos. As of today, there is no facility that can provide a low-energy antiproton-radioactive ion collider. At CERN (Switzerland), however, the existence of both a Radioactive Ion Beam facility (ISOLDE) and a facility to produce antiprotons (the Antimatter Factory) provides a feasible ground to generate these interactions. The antiProton Unstable Matter Annihilation experiment (PUMA) aims at transporting 10e9 antiprotons from the Antimatter Factory to ISOLDE to study the nuclear density tail by measuring the neutron-to-proton annihilation ratio of both stable and short-lived nuclei. In this work, the development of the Time Projection Chamber (TPC), main detection component of the charged annihilation products, is presented. As the detector aims at being inserted into the bore of the 4 T solenoid of PUMA, a compact and low-maintenance device is required. The geometrical design was based on Monte-Carlo simulations optimized for detection efficiency and charge identification. The electrical design was also optimized to provide an homogeneous electric field in the drift region of the detector. Finally, the mechanical design was performed. The sensitivity of the method used at PUMA is investigated with an atomic cascade code applied to antiprotonic tin and calcium atoms to study the impact of the unknown capture states. Benchmarks of the code with X-ray data provide an initial estimation of the capture parameters and the cascade calculations show that 70% of the annihilations occur at the circular states (n, l = n−1), validating the PUMA concept. The isotopic sensitivity of the annihilation width ratio obtained from the measurement is quantified. Additional theoretical developments that describe the full capture and cascade are needed to account for the impact of low-l annihilations which are here observed to be non-negligible. |
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| Status: | Verlagsversion | ||||
| URN: | urn:nbn:de:tuda-tuprints-228514 | ||||
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 530 Physik | ||||
| Fachbereich(e)/-gebiet(e): | 05 Fachbereich Physik 05 Fachbereich Physik > Institut für Kernphysik 05 Fachbereich Physik > Institut für Kernphysik > Experimentelle Kernphysik |
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| Hinterlegungsdatum: | 12 Dez 2022 13:09 | ||||
| Letzte Änderung: | 13 Dez 2022 06:31 | ||||
| PPN: | |||||
| Referenten: | Obertelli, Prof. Dr. Alexandre ; Nörtershäuser, Prof. Dr. Wilfried | ||||
| Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 26 Oktober 2022 | ||||
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