The first device that comes to mind as a radiation detector (for use in schools) is probably the Geiger-Mueller (GM) tube. Although GM tubes can be used to detect all three types of ionising nuclear radiation (alpha, beta and gamma) they are subject to some important limitations. These shortcomings will be discussed below, together with … Continue reading Radiation detectors
Does radiation make things radioactive?
The short answer is “no” but the devil is always in the detail. Firstly, “radiation” here applies specifically to ionising radiation; alpha particles, beta particles and gamma photons. In particular, we are excluding non-ionising nuclear radiation in the form of neutrons, which definitely can turn previously stable nuclei into radioactive materials. This effect is a … Continue reading Does radiation make things radioactive?
Electron Capture and Internal Conversion
Having looked at some of the finer details for beta decay in two previous posts (Q-Value and Metastable Nuclei) it seems fitting to round-off this short series with two phenomena that involve orbiting electrons rather than just nucleons. The first effect is electron capture. As its name suggests, this is when an orbiting electron is … Continue reading Electron Capture and Internal Conversion
Technetium-99m
At first glance the decay of molybdenum-99 to produce technetium-99 is a straightforward beta process. The total number of nucleons is unchanged but the number of protons increases by one with the emission of an electron and an electron-antineutrino. The half-life for this decay is 66 hours. In the nuclear decay equation above, technetium-99 is … Continue reading Technetium-99m
Beta Decay Q-value
At GCSE level, beta decay is said to be the emission of an electron (or positron, in beta-plus decay) when an unstable nucleus transforms into a more stable nucleus. The parent and daughter nuclei are different elements with the same nucleon number (sum of neutrons and protons) but their proton numbers vary by +1 for … Continue reading Beta Decay Q-value
Beta Decay and Energy Conservation
I have just finished reading an excellent book that traces various theories about beta decay in the first third of the Twentieth Century. Controversy and Consensus: Nuclear Beta Decay 1911-1934 is an editted version of the successful PhD thesis written by Carsten Jensen, who clearly had a deep passion for unravelling physics history but died … Continue reading Beta Decay and Energy Conservation
How reliable are AI assistants?
To explore the current state of AI reliability in a physics context, two questions were put to five free AI assistants, all available via https://duck.ai/; Why don’t radioactive decay chains end with iron? Which isotope has the highest binding energy? Before revealing the AI responses, here are my own answers. Question 1 assumes that all … Continue reading How reliable are AI assistants?
How to Use Logarithms
Although they can seem confusing at first sight, logarithms are just mathematical functions that allow calculations to be carried out quicker than would otherwise be the case. So although they may seen daunting, you should think of logarithms as a way to make calculations easier – once you have mastered the rules. There is quite a … Continue reading How to Use Logarithms
Hideki Yukawa and Meson Theory
How does the nucleus of an atom stay together? Why don’t the positively-charged protons repel each other and cause the nucleus to disintegrate? The early models of the atom imagined solid spheres, perhaps with different sizes, shapes or “colours” distinguishing one type of atom from another. Then came J J Thomson’s discovery of the electron … Continue reading Hideki Yukawa and Meson Theory
Radiation and Altitude
The discovery of radioactive rocks was unexpected but when physicists attempted to discover how far the new “penetrating rays” could reach, they were in for an even bigger surprise. Henri Becquerel’s discovery that uranium salts emit penetrating radiation was one of science’s great “accidents”. Uranium was first identified in 1789 but it was a century … Continue reading Radiation and Altitude
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