Tagged Questions
0
votes
0answers
39 views
Find mass of Plutonium in alpha decay [closed]
I did:
$$\Delta mc^2 = (m_{Pu}+m_{U}+m_{He})c^2$$
$$\frac{5.24 \times 10^6 eV}{(3 \times 10^8)^2} = m_{Pu} + 235.043924 + 4.002603$$
$$m_{Pu} = 239.0465$$
But answer is 239.052157, slightly ...
1
vote
2answers
67 views
Alpha particle and helium nucleus
The symbol for the alpha particle is α or $α^{2+}$, it can be written as $He^{2+}$.
What I want to know is that, are they same? I mean alpha particle and helium nucleus are same or any subtle ...
8
votes
4answers
177 views
Why are alpha particles such a prominent form of radiation and not other types of nucleon arrangement?
It is said in many textbooks that alpha decay involves emitting alpha particles, which are very stable. Indeed, the binding energy (~28.3 MeV) is higher than for $Z$-neighboring stable isotopes. But ...
3
votes
1answer
298 views
Kinetic energy of alpha-particle in $^{212}$Po decay
Admittedly, Nuclear Physics is not my strength. I'm writing a simulation to model alpha-decay. So far, I have looked up the values of the kinetic energy of the alpha particles that are emitted in a ...
1
vote
1answer
34 views
Nuclear transition notation
I have a question which asks me to determine what x is for the following nuclear transition
$$^{29}Si(\alpha, n)X$$
But I don't have any idea what this notation implies.
Another example:
...
-1
votes
1answer
104 views
Determining energy of gamma-rays after alpha-decay of Am-241
So it turns into Np, and electrons just falling into 'free new' levels and emmiting, right?
Give me a link where to read, please, if it's very easy to answer.
0
votes
0answers
71 views
Beta decay for Ar-38, K-38, Cl-38
I want to prove that $^{38}Ar$ is stable with respect to $\beta$ decay, that $^{38}Cl$ decays by $\beta^-$ and that $^{38}K$ decays by $\beta^+$.
I know from Googling that this is true, and I also ...
4
votes
1answer
54 views
$\alpha$ decay to more than one nuclear state
I do not understand how $\alpha$ decay can be a probabilistic process such that there are multiple products from the decay. For example:
$^{241}\mathrm{Cm}$ decays to the excited states of ...
4
votes
1answer
130 views
Radiation exposure to a child who was briefly in the presence of an adult who had received a 18FDG PET scan
I am a physician who thought she was good at math, but apparently am not as I cannot figure out this mathematical/physics question. (My background is obviously NOT nuclear medicine!) A family friend ...
1
vote
1answer
70 views
Does the strong (nuclear) force ever contribute to decay?
Does the strong (nuclear) force ever contribute to decay ?
Or is the weak nuclear force the only decaying force ?
2
votes
1answer
84 views
Alpha-stable isotopes
Why some isotopes with positive alpha-decay energy are stable? For example, alpha-decay energy of stable 194Pt is about 1.5 MeV.
But there is no stable isotopes with positive beta-decay energy.
...
1
vote
2answers
171 views
Where does the “borrowed energy” come from in Alpha decay?
I was also thinking about the uncertainty principle in regards with energy & time. The question of something like:
Alpha tunneling out of the nucleus is where this can be invoked, but having an ...
1
vote
1answer
52 views
References for nuclear masses, mass deficits, decay rates and modes
Where can I find the base data for computing the energy release of nuclear decays and the spectra of the decay products?
My immediate need is to find the energy release by the beta decay of Thorium ...
1
vote
3answers
168 views
Neutron decay and electron anti neutrino $n\to p + e + \bar{\nu}_e$
Why do we need neutrino to explain neutron decay?
Is there any evidence regarding existence neutrinos in the context of
$n\to p + e + \bar{\nu}_e$?
8
votes
2answers
1k views
Why are alpha particles made of 2 protons and neutrons?
When experiencing alpha decay, atoms shed alpha particles made of 2 protons and 2 neutrons. Why can't we have other types of particles made of more or less protons?
5
votes
2answers
552 views
“Dear radioactive ladies and gentlemen” - Letter by Wolfgang Pauli
In 1930, Wolfgang Pauli wrote a letter to Lise Meitner for a convention in Tübingen, considering the problem of beta decay.
Does anybody know, where to find the original letter online ?
0
votes
0answers
49 views
Problem on nuclear physics radioactivity [duplicate]
Possible Duplicate:
How do we know that C14 decay is exponential and not linear?
Please help me solving this problem.
Find the half life period of uranium-238,if one gram of it emits ...
6
votes
1answer
254 views
Does neutron radiation form clouds?
I've heard a couple of scary stories from experienced accellerator physiscists about something called neutron clouds. Apparently, if you have an experiment like a fixed-target experiment that produces ...
5
votes
2answers
704 views
Tunneling of alpha particles
Consider this explanation of the alpha decay: It says
The Coulomb barrier faced by an alpha
particle with this energy is about 26
MeV, so by classical physics it cannot
escape at all. ...
3
votes
2answers
580 views
What is the required thickness of concrete needed to entomb a leaking reactors emissions?
What is the minimum thickness of an aggregate concrete membrane to prevent radioactive particles from escaping a broken reactor?
I am interested in calculating the amount of concrete required to ...
1
vote
2answers
230 views
$\alpha$ and $\beta$-decay, why don't they neutralize each other?
$\alpha$ radiation consist of positive charged helium nuclei, $\beta$ radiation of negative charged electrons. So why don't the $\alpha$ particles take those electrons to get neutral?
3
votes
3answers
217 views
Ratio of radiation sources in the uranium cycle
Sorry, I know y'all are probably getting a lot of questions re: Fukushima, but I had a very specific one and no-one has been able to answer it.
I am specialised in medical radiation, and have been ...
6
votes
1answer
607 views
Why doesn't orbital electron fall into the nucleus of Rb85, but falls into the nucleus of Rb83?
Rb83 is unstable and decays to Kr-83. Mode of the decay is electron capture. Rb85 is stable.
The nuclei Rb83 and Rb85 have the same charge. Rb85 is heavier than Rb85, but gravitation is too weak to ...
9
votes
6answers
779 views
Is there any thing other than time that “triggers” a radioactive atom to decay?
Say you have a vial of tritium and monitor their atomic decay with a geiger counter. How does an atom "know" when it's time to decay? It seems odd that all the tritium atoms are identical except with ...
10
votes
3answers
765 views
Why some nuclei with “magic” numbers of neutrons have a half-life less than their neighbor isotopes?
It's easy to find the "magic" numbers of neutrons on the diagrams of alpha-decay energy: 82, 126, 152, 162. Such "magic" nuclei should be more stable than their neighbors.
But why some nuclei ...
