Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Analysis of deuteron evaporstion from 64Ge*, 56Ni*, and 52Fe*

Mc Caughley, Sean Francis Donnell LU (2024) FYSK04 20241
Department of Physics
Particle and nuclear physics
Abstract
This paper analyses deuteron evaporation in comparison to the evaporation of a proton-neutron pair for different compound nuclei. The main reaction is the fusion-evaporation reaction of 40Ca on 24Mg target leading to the formation of the 64Ge∗ compound nucleus, along with other contamination reactions. The experimental dataset is obtained from Argonne National Laboratory. Projections on γ-γ matrices were used to analyse the γ-ray spectra of 61Zn, 58Cu, 53Fe, and 49Cr. The results suggest that the relative rate of deuteron evaporation compared to a proton-and-neutron evapora-tion has a dependence on spin and excitation energy for the dp and 2pn evaporation channel. The rate of deuteron evaporation may also have a mass number dependence.
Popular Abstract
The research area of nuclear physics remains an important and ever evolving field of study in the modern age. The field focuses on studying the tiny core at center of every atom in the universe called the nucleus. As our understanding of the nucleus has increased over the last century our knowledge of how to apply nuclear physics has become a staple of modern medicine, smoke detectors, imaging, and energy production, to name but a few. Our understanding of the inner workings of the nucleus is also evolving. The rapid growth in modern technology has allowed for continued improvement on experimental techniques and equipment allowing for deeper study into the inner workings of natures building blocks.

Many experiments have been performed... (More)
The research area of nuclear physics remains an important and ever evolving field of study in the modern age. The field focuses on studying the tiny core at center of every atom in the universe called the nucleus. As our understanding of the nucleus has increased over the last century our knowledge of how to apply nuclear physics has become a staple of modern medicine, smoke detectors, imaging, and energy production, to name but a few. Our understanding of the inner workings of the nucleus is also evolving. The rapid growth in modern technology has allowed for continued improvement on experimental techniques and equipment allowing for deeper study into the inner workings of natures building blocks.

Many experiments have been performed on atoms to further our understanding of the nucleus. A popular area of research is the so called N = Z line. The N = Z line represents nuclei, which have an equal number of protons and neutrons. In general, such nuclei are relatively stable up to N = Z ≈ 30 allowing for easier experimentation. Investigation of the evaporation of light particles from the excited states in the N = Z nucleus 64Ge by means of improved radiation detector systems has led to the exciting experimental discovery of deuteron evaporation from unstable nuclei.


A deuteron is a nucleus that is composed of one proton and one neutron. A small quantity of energy is required to disassemble this loosely bound system. The nucleus is vital for the formation of matter in the universe as it is one of the first processes of fusion in stars like the sun.

What does it mean for deuterons to evaporate? Deuteron evaporation was observed using an experimental technique known as a fusion-evaporation reaction. This is performed by accelerating a nucleus to speeds a fraction of the speed of light and colliding it with a stationary target nucleus. The massive amount of energy allows for the two nuclei to fuse into what is known as a ’compound nucleus’. The compound nucleus is in a highly volatile state. The nucleus wishes to release energy in order to become more stable. To cool down the nucleus would first eject or ’evaporate’ a combination of protons, neutrons, and α particles and then subsequently further de-excite by emitting electromagnetic radiation. Studying the, ’light’ emitted from the nucleus after evaporation gives great insight on the composition of a nucleus.

In principle the forming of deuterons in the nucleus and the possibility of evaporation from a nucleus is possible. The barrier for discovery was that the detection technology could usually not clearly distinguish between the evaporation of a proton or deuteron. This changed in 2020 during an experimental campaign at Argonne National Laboratory (ANL). During the campaign a telescope detector was added to the experimental setup. The experiment accelerated a beam of 40Ca into a thin sheet of 24Mg resulting in the formation of the 64Ge∗ compound nucleus. The telescope detector provided improved energy resolution and during investigation of the experimental data it was discovered that deuteron evaporation was now clearly visible, providing experimental confirmation of deuteron evaporation.

As with any exciting discovery many further questions arise. At what rates are deuterons evaporated from different compound nuclei? What are the differences between evaporating a deuteron over a proton-neutron pair? By studying datasets from the the 2020 campaign at ANL I will come closer to answering these questions. (Less)
Please use this url to cite or link to this publication:
author
Mc Caughley, Sean Francis Donnell LU
supervisor
organization
course
FYSK04 20241
year
type
M2 - Bachelor Degree
subject
language
English
id
9159580
date added to LUP
2024-08-12 09:44:20
date last changed
2024-08-12 09:44:20
@misc{9159580,
  abstract     = {{This paper analyses deuteron evaporation in comparison to the evaporation of a proton-neutron pair for different compound nuclei. The main reaction is the fusion-evaporation reaction of 40Ca on 24Mg target leading to the formation of the 64Ge∗ compound nucleus, along with other contamination reactions. The experimental dataset is obtained from Argonne National Laboratory. Projections on γ-γ matrices were used to analyse the γ-ray spectra of 61Zn, 58Cu, 53Fe, and 49Cr. The results suggest that the relative rate of deuteron evaporation compared to a proton-and-neutron evapora-tion has a dependence on spin and excitation energy for the dp and 2pn evaporation channel. The rate of deuteron evaporation may also have a mass number dependence.}},
  author       = {{Mc Caughley, Sean Francis Donnell}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Analysis of deuteron evaporstion from 64Ge*, 56Ni*, and 52Fe*}},
  year         = {{2024}},
}