uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
Dipartimento di Fisica dell’Università, Sezione di Padova, I-35122 Padova, Italy.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics. (Nuclear structure group)
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
Show others and affiliations
2011 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 638, no 1, 96-109 p.Article in journal (Refereed) Published
Abstract [en]

The interaction position resolution of the segmented HPGe detectors of an AGATA triple cluster detector has been studied through Monte Carlo simulations and in an in-beam experiment. A new method based on measuring the energy resolution of Doppler-corrected γ-ray spectra at two different target to detector distances is described. This gives the two-dimensional position resolution in the plane perpendicular to the direction of the emitted γ-ray. The γ-ray tracking was used to determine the full energy of the γ-rays and the first interaction point, which is needed for the Doppler correction. Five different heavy-ion induced fusion-evaporation reactions and a reference reaction were selected for the simulations. The results of the simulations show that the method works very well and gives a systematic deviation of in the FWHM of the interaction position resolution for the γ-ray energy range from 60 keV to 5 MeV. The method was tested with real data from an in-beam measurement using a 30Si beam at 64 MeV on a thin 12C target. Pulse-shape analysis of the digitized detector waveforms and γ-ray tracking was performed to determine the position of the first interaction point, which was used for the Doppler corrections. Results of the dependency of the interaction position resolution on the γ-ray energy and on the energy, axial location and type of the first interaction point, are presented. The FWHM of the interaction position resolution varies roughly linearly as a function of γ-ray energy from 8.5 mm at 250 keV to 4 mm at 1.5 MeV, and has an approximately constant value of about 4 mm in the γ-ray energy range from 1.5 to 4 MeV.

Place, publisher, year, edition, pages
2011. Vol. 638, no 1, 96-109 p.
Keyword [en]
gamma-ray tracking, AGATA, Monte Carlo simulations, HPGe detectors, Fusion-evaporation reactions
National Category
Subatomic Physics
Identifiers
URN: urn:nbn:se:uu:diva-106820DOI: 10.1016/j.nima.2011.02.089ISI: 000290082600015OAI: oai:DiVA.org:uu-106820DiVA: diva2:405540
Available from: 2011-03-22 Created: 2009-07-05 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Collective Structure of Neutron-Rich Rare-Earth Nuclei and Development of Instrumentation for Gamma-Ray Spectroscopy
Open this publication in new window or tab >>Collective Structure of Neutron-Rich Rare-Earth Nuclei and Development of Instrumentation for Gamma-Ray Spectroscopy
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Neutron-rich rare-earth nuclei are among the most collective nuclei that can be found in nature. In particular, the doubly mid-shell nucleus 170Dy is expected to be the nucleus where the collective structure is maximized. This has implications for the astrophysical r-process, since it has been suggested that the collectivity maximum plays an important role in the abundances of the rare-earth elements that are created in supernova explosions. In this work, the collective structure of the five nuclei 168,170Dy and 167,168,169Ho are studied and different theoretical models are used to interpret the evolution of collectivity around the mid-shell. In order to produce and study even more neutron-rich nuclei in this mass region, new radioactive ion beam facilities will be a valuable tool. These facilities, however, require advanced instruments to study the weak signals of exotic nuclei in a high background environment. Two of these instruments are the γ-ray tracking spectrometer AGATA and the neutron detector array NEDA. For AGATA to work satisfactorily, the interaction position of the gamma rays must be determined with an accuracy of at least five millimetres. The position resolution is measured in this work using a model independent method based on the Doppler correction capabilities of the detector at two different distances between the detector and the source. For NEDA, one of the critical parameters is its ability to discriminate between neutrons and γ rays. By using digital electronics it is possible to employ advanced and efficient algorithms for pulse-shape discrimination. In this work, digital versions of the common analogue methods are shownto give as good, or better, results compared to the ones obtained using analogue electronics. Another method which effectively distinguishes between neutrons and γ rays is based on artificial neural networks. This method is also investigated in this work and is shown to yield even better results.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2011. 122 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 818
Keyword
nuclear structure, collective models, 150 < A < 189, AGATA, HPGe detectors, gamma-ray tracking, NEDA, pulse-shape discrimination, neutrons, neural network
National Category
Subatomic Physics
Research subject
Physics with specialization in Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-149772 (URN)978-91-554-8056-1 (ISBN)
Public defence
2011-05-20, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2011-04-29 Created: 2011-03-22 Last updated: 2011-05-05Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Söderström, Pär-AndersAl-Adili, Ali

Search in DiVA

By author/editor
Söderström, Pär-AndersAl-Adili, Ali
By organisation
Nuclear PhysicsApplied Nuclear Physics
In the same journal
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Subatomic Physics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 636 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf