# Tag Info

0

It's likely not dangerous, especially sitting in your garage. A count rate reading from a GM tube tells you very little. Not only is there no information about the energy of the radiation being recorded, you make no mention of the distance your probe was from the source during the time of the reading. You also failed to specify a background count rate. A ...

0

Even in your "reference article" it it said: "The actual amount of radioactivity is extremely low -less than the normal background radiation you get from rocks and stuff" and "if in fact it's a problem, is that uranium is a heavy metal, as is lead [;]both could leach into food, particularly if it's acidic." So if you really wonder the risk for your health, ...

0

The way to approach the problem initially is to consider what you know about the reaction $$n \longrightarrow \mathrm{p}^+ + \mathrm{e}^- + \bar{\nu}_e \,.$$ Because of the relativity principle we can consider the reaction in the rest-frame of the neutron without loss of generality and we know that both (three-)momentum and energy are conserved. ...

1

The thing about Feynman diagrams is that they are rotatable and that they try to maintain a direction of progression of time. In this specific circumstance, it seems time flows from bottom to top. It indicates that the proton, electron, and neutrino are products, outputs from the interaction. If rotated, the inputs and outputs would change. In that way, the ...

0

First, while $\beta$ particles were identified early in the study of radioactive decay, the classic $\beta$ particle is a high-energy electron, part of $\beta$ - decay. Such an electron does not usually produce $\gamma$ radiation. On the other hand, $\beta$ + decay produces a positron, and this will quickly encounter an electron, the two will ...

2

You might want to do some basic reading about beta decays. Wikipedia at the very least. Beta decay comes in two flavors, + and -. In both cases a neutron decays into a proton and either an electron and an antineutrino or a positron and a neutrino. The emitted electrons/positrons are sometimes called Beta radiation, and I assume this is what you're talking ...

0

The electrons are also jittering, and because these are charged particles they will emit light when accelerating. For example electrons will have certain rotational and vibrational modes of oscillation.

2

These sorts of calculations are part of the design process for spallation sources and are done quite carefully. The tool of choice is MCNP, which has been extensively benchmarked over many decades. MCNP is maintained by folks at LANL, which happens to have a tantalum-clad tungsten spallation target; if you are on-site at LANL you should invite someone from ...

3

I've cross checked it with some known isotopes which decay by Cluster Decay. It would appear to be that. I guess it stands for Cluster Emission.

1

The electromagnetic self-force problem has been solved recently, see here; the gravitational self-force problem has also been solved recently, see this article.

1

I stumbled across this question and wanted to reply to one particular part of it: Lastly, despite the Wikipedia article somewhat addressing the topic, is this problem of self-force present with other forces (e.g. gravity)? I believe it does state that standard renormalization methods fail in the case of GR and thus the problem is still present ...

0

All I can think of is EEG (electroencephalography) signal. It is a diagnostic technique that allows to monitor brain electrical activity by measuring potentials on the scalp. As I know there are some contactless methods of measuring those potentials, but I have no idea if you can measure it from big distance, since it is quite a weak signal. This is one ...

20

There are many ways to detect a nuclear explosion, and there are people working to detect it. The Comprehensive Nuclear-Test-Ban Treaty Organization or CTBTO is one such organization. They are using a global network called the International Monitoring System. This is capable of detecting any nuclear detonations anywhere on the Earth (underwater, or in the ...

3

All the Sun's power $P$ passes uniformly through a sphere with radius of 1 AU. Calculate the total surface area of this sphere and call it $S$. The Earth's disc also has a surface area that can be calculated from its radius. Call this surface $S_E=\pi R_E^2$. The fraction of the Sun's power received by the Earth is thus: $f=P\frac{S_E}{S}$.

0

Bismuth has a higher Z-value, and attenuation increases with increasing Z-value, although the difference in Z is not that large in this case so I doubt it is a very strong effect. Regardless, the attenuation of the two materials add linearly (neglecting build-up), so the best thing to do is to calculate the attenuation coefficient for the actual materials ...

2

There are such devices, but they are rather limited in their electrical output and do require you to carry a big chunk of radioactive material around. Ironically their only commercial use was implanted pacemakers! If you are going to use radiation to make energy it's easier to use a safer alpha emmitter and just use the heat to generate electricity by the ...

0

An oscillating magnetic field always induces an oscillating electric field. So, the "magnetic field oscillating at radio frequency" is just shorthand for a radiofrequency electromagnetic field: both electric and magnetic fields are present. I believe the manual chooses to emphasize the magnetic field because it is the magnetic field that couples directly ...

0

In Rutherford Backscattering Spectrometry (RBS), the detector of choice for MeV protons and alphas is a surface barrier detector. As @onelineproof mentions, some are made of germanium. For the last 30 years or so, silicon detectors have been much more common. These are basically reverse-biased diodes with a very thick active area to collect charge generated ...

0

I believe Germanium is commonly used for alpha particle spectroscopy. It is a semiconductor, measures the amount of electrons that result from the creation of electron-hole pairs as the alpha particle passes through the material. The electronics connected to the anode (+) plate measures the voltage change across the two plates sandwiching the sensitive area ...

Top 50 recent answers are included