From nuclei to neutron stars: simple binding energy computer modelling in the classroom (part 1)

Abstract

We present a simple activity based on the liquid-drop model which allows secondary school students to explore the uses of mathematical models and gain an intuitive understanding of the concept of binding energy, and in particular the significance of positive binding energy. Using spreadsheets provided as supplementary material, students can perform simple manipulations on the different coefficients of the model to understand the role of each of its five terms. Students can use the spreadsheets to determine model parameters by optimising the agreement with real atomic mass data. This activity can be used as the starting point of a discussion about theoretical models, their validation when it comes to describing experimental data and their predictive power towards unexplored regimes.

From nuclei to neutron stars: simple binding energy computer modelling in the classroom (part 2)

“…M N,Z c 2 is the rest mass of the isotope. More details and introductory activities on binding energies are available in Part 1 [5] and Ref. [27].…”

“…In a previous paper (hereafter referred to as Part 1 [5]), we have introduced a series of online, spreadsheet-based activities that provide an introduction to nuclear physics models in the context of nuclear binding. Unlike previous BB efforts based on experimental nuclear data [1] or on nuclear processes [6], these activities focus on a theoretical model.…”

“…In our first proposed activity, we extend the LD model of Part 1 [5] to the neutronrich regime and supplement it with a binding energy term of a gravitational origin. By looking at the limits of binding in this case, we can derive an expression for the minimum mass of a neutron star [21].…”

“…A minimal instruction set and some online background material (such as the video here §) may be helpful in this case. Alternatively, the activities could be part of a group discussion or a demonstrator-led outreach or educational session -in conjunction with those presented in Part 1 [5]. Either way, the spreadsheets provided can be used to illustrate visually concepts associated to binding, nuclear physics, astrophysics and general relativity.…”

“…The article is organised as follows. We start with a generic discussion on binding energies and the LD model in the following section, providing a short overview of Part 1 [5]. Section 3 is devoted to the neutron-star activities.…”