Assessment of the Capability for Vetoing Beta-Decay Events in the Lundium Decay Station
(2022) FYSK02 20212Nuclear physics
Department of Physics
- Abstract
- Alpha decay spectroscopy using the latest and most sensitive detector setup as well as fast sampling read-out electronics has become very important for discovery and analysis of short-lived nuclei created in collision experiments in the laboratory. The Nuclear Structure Group in Lund is currently developing the Lundium Decay Station for use in comprehensive nuclear spectroscopy of decays for rare isotopes, particularly in the heavy & superheavy region. In this thesis work, the performance of the veto detector in the Lundium decay station is investigated to observe how well the implantation detector can distinguish low energy signals of to-be-reconstructed alpha particles from beta particles passing through. To investigate this, a Bi-207... (More)
- Alpha decay spectroscopy using the latest and most sensitive detector setup as well as fast sampling read-out electronics has become very important for discovery and analysis of short-lived nuclei created in collision experiments in the laboratory. The Nuclear Structure Group in Lund is currently developing the Lundium Decay Station for use in comprehensive nuclear spectroscopy of decays for rare isotopes, particularly in the heavy & superheavy region. In this thesis work, the performance of the veto detector in the Lundium decay station is investigated to observe how well the implantation detector can distinguish low energy signals of to-be-reconstructed alpha particles from beta particles passing through. To investigate this, a Bi-207 source was used to radiate electrons on an implantation plus veto detector, back-to-back, setup at a distance very close to the face of the implantation detector. Data on the number and position of energy depositions (hits) recorded on both of them are analysed and used to build distributions of the electrons spread on the veto detector while ‘gating’ on pixels hit on the implantation detector. This very important finding allows one to determine how far apart hits on the two detectors can be for a beta particle passing through and still be considered to be from that same particle; this is becoming increasingly important as more (and new) fine structure of the alpha decays is investigated. The standard deviations calculated for the veto detector hit distributions, that can then be used to set electron hits apart in actual experiments to a suitable confidence level, was found to be about 4 mm. (Less)
- Popular Abstract
- To identify and analyse the heavy and superheavy nuclei created in the lab, one measures a sequence or ‘chain’ of so-called decays, where often a charged ‘alpha’ particle – i.e. a group of 4 nucleons – is ejected out from the nuclei. Beta decay is another type of decay where lighter, charged beta particles – electrons – are emitted, and as a result there are situations when it is necessary to distinguish between the incorrectly detected alphas and the betas.
To solve this mystery, two charged particle detectors are used in a back-to-back set-up (the first known as ‘implantation’ while the second ‘veto’) to observe charged particles incident on them. Alphas are only picked out in ‘photos’ taken , referred to as hits, by the implantation... (More) - To identify and analyse the heavy and superheavy nuclei created in the lab, one measures a sequence or ‘chain’ of so-called decays, where often a charged ‘alpha’ particle – i.e. a group of 4 nucleons – is ejected out from the nuclei. Beta decay is another type of decay where lighter, charged beta particles – electrons – are emitted, and as a result there are situations when it is necessary to distinguish between the incorrectly detected alphas and the betas.
To solve this mystery, two charged particle detectors are used in a back-to-back set-up (the first known as ‘implantation’ while the second ‘veto’) to observe charged particles incident on them. Alphas are only picked out in ‘photos’ taken , referred to as hits, by the implantation detector, while electrons are able to be seen using both. However, there can be times when the fast electrons are emitted from the nuclei at a very sharp angle that it acts sneaky and is detected in the veto detector at a position not coincident with the detection position in
the implantation detector. Thus, it becomes an issue to label the particle as an electron or an escaping alpha. To tackle this issue, an electron source – so there are no alphas to worry about and any hits not coincident in position are still caused only by the electrons – is used to irradiate the implantation and veto detector setup. By looking at the spread of the electron hits on the veto detector for certain selected ‘pixel’ hits – i.e. hit positions – on the implantation detector, one can determine how far the hits on the two detectors can be
for identifying an impostor alpha, i.e. labeling the incoming particle as an electron.
This investigation, which is the first of its kind in house, will improve identification and analysis of the rare heavy and superheavy isotopes, making them more accurate and ensuring that no false alpha are being considered in the decay chains determined. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9074978
- author
- Sayed, Tanvir LU
- supervisor
-
- Luis Sarmiento LU
- Daniel Cox LU
- organization
- course
- FYSK02 20212
- year
- 2022
- type
- M2 - Bachelor Degree
- subject
- keywords
- Radioactivity, Decays, Radiation, Ionisation, Superheavies, Exotic isotopes, Decay spectroscopy, Semiconductors, Silicon-Strip Detectors, Lundium, Vetoing, Electron spread, Particle identification
- language
- English
- id
- 9074978
- date added to LUP
- 2022-02-10 11:59:55
- date last changed
- 2022-02-10 11:59:55
@misc{9074978,
abstract = {{Alpha decay spectroscopy using the latest and most sensitive detector setup as well as fast sampling read-out electronics has become very important for discovery and analysis of short-lived nuclei created in collision experiments in the laboratory. The Nuclear Structure Group in Lund is currently developing the Lundium Decay Station for use in comprehensive nuclear spectroscopy of decays for rare isotopes, particularly in the heavy & superheavy region. In this thesis work, the performance of the veto detector in the Lundium decay station is investigated to observe how well the implantation detector can distinguish low energy signals of to-be-reconstructed alpha particles from beta particles passing through. To investigate this, a Bi-207 source was used to radiate electrons on an implantation plus veto detector, back-to-back, setup at a distance very close to the face of the implantation detector. Data on the number and position of energy depositions (hits) recorded on both of them are analysed and used to build distributions of the electrons spread on the veto detector while ‘gating’ on pixels hit on the implantation detector. This very important finding allows one to determine how far apart hits on the two detectors can be for a beta particle passing through and still be considered to be from that same particle; this is becoming increasingly important as more (and new) fine structure of the alpha decays is investigated. The standard deviations calculated for the veto detector hit distributions, that can then be used to set electron hits apart in actual experiments to a suitable confidence level, was found to be about 4 mm.}},
author = {{Sayed, Tanvir}},
language = {{eng}},
note = {{Student Paper}},
title = {{Assessment of the Capability for Vetoing Beta-Decay Events in the Lundium Decay Station}},
year = {{2022}},
}