Decay Definition and 998 Threads

I believe the neutron decays with a half life around 12 minutes via the weak mechanism. I'm wondering what causes a particular neutron to decay. At the moment the neutron decays, has it encountered (run into) a stray weak field? Or ... does the neutron decay just because of internal forces...

I can offer no further insight.

Homework Statement Homework Equations http://img42.imageshack.us/img42/7931/image24yc.jpg The Attempt at a Solution To make things easier I just scanned my work - I'm at a loss of what to do next :( [PLAIN][PLAIN]http://img816.imageshack.us/img816/6139/image25t.jpg Thanks a...

hello! i'm planning to build such a generator, but i have some questions: 1. what dimensions and materials are needed to shield one typical geiger-muller tube from the background radiation? 2. even with the complete protection, is it possible that the counter tube will trigger without...

Basic premise: a pure tone sine wave can be modeled with a pendulum and the rate of amplitude decay can be manipulated with a friction coefficient. So... does anyone know how this is actually done? In other words if you picked a pure tone (let's say middle C @ 261.6 Hz) initiated at a certain...

Hi, I've noticed that the same method is used to derive both decay rate and the reaction rate for a unimolecular reaction. The thing I don't understand is, how do we know that the rate of a nuclear reaction is only dependent on k*t I mean with chemistry, this is something you find out...

Homework Statement What is the kinetic energy given to the proton in the decay of the neutron when a) the electron has negligibly small kinetic energy; b)antineutrino has small negiligibly energy Homework Equations The decay reaction n\Rightarrow p+e^{-}+\bar{\nu} now I try to...

Homework Statement A plutonium-239 nucleus, initially at rest, undergoes alpha decay to produce a uranium-235 nucleus. The uranium-235 nucleus has a mass of 3.90x10^-25 kg, & moves away from the location of the decay with a speed of 2.62x10^5 m/s. Determine the minum electric potential...

Hi, I have a question regarding the types of decay and the time of decay for an atomic nucleus. Do all nuclei have a set decay time and method, (by method I mean Alpha, Beta, Gamma decay). i.e. does Uranium only decay via beta decay over a set time? Or can an nucleus decay by any of the...

I read that gamma rays are usually emitted by the nucleus of an atom after it emits an alpha particle, but have been wondering: If the alpha particle being emitted was meant to stabilize the atom, and should have, why does the nucleus need to emit such high energy waves?

How do we calculate the decay width or the mean lifetime of neutron/

Homework Statement A radioactive nucleus can decay by two different processes. The half life for the first processes is t_{1} and that for the second is t_{2}. Show that the effective half life t of the nucleus is given by \frac{1}{t}=\frac{1}{t_{1}}+\frac{1}{t_{2}}Homework Equations...

Is there any explanation why the \Xi^0 decays to \Lambda^0 + \pi^0 and not to \Lambda^0 + \pi^-+\pi^+ ?

Homework Statement A particle of mass M, traveling horizontally through the laboratory, decays into two daughter particles, each of mass 0.4M. One of the daughters, A, is produced at rest in the Lab frame. Show that vcm , the speed with which the CM frame moves in the Lab frame, is equal...

Here's a ques. I am having problem with: sample of gold is bombard with 2*10^10 neutrons per sec. it cause the Au(A=197) become radioactive (Au(A=198)) which decay with half life time of 2.969day (through beta decay 1. how many Au(A=198) will be after 5 days of bombardment? 2. how many...

Hey so, I was just wondering: If Carbon-14 (6 protons, 8 neutrons) decays into an electron, a neutrino, and Nitrogen 14 (7 protons, 7 neutrons) How is charge conserved? I get that nucleons are conserved, but if nitrogen-14 is neutral, then it has 7 protons and 7 electrons, versus Carbon...

Homework Statement You have two samples that exhibit radioactive decay. The first gives you initially a 1000/s decay rate and after one hour a 500/s decay rate. The second gives you initially a 500/s decay rate and after one hour a 250/s decay rate. Which sample has a higher probability per...

Hi I need help to understand Feynman rules for decay for exams. In past paper there is the following question as whether the following are allowed. cc decays to tau++tau-. From What I can see this is possible via the strong force is this correct? The next is cc decays to cu and cu. From...

Why is the emf induced in an inductor much larger when the switch connecting it to a battery is closed than when the switch is opened? Somewhere in a text I had read that di/dt is very large when an LR circuit breaks but then its value for growth and decay in an LR circuit is...

In beta decat the u quark fromthe proton and the d quark from the neutron interact to produce a electron and it's neutrino. I'm wondering about the charge conservation of this process because a neutron has zero charge and a proton has charge of 1. How do we end up with a electron charge of -1 at...

If we assume R-parity like in MSSM, shouldn't the lightest supersymmetric electrically charged particle be fairly stable? My question is two fold: 1] if we assume R-parity and supersymmetry (at least at high energies) is there a fairly model independent (ie. no details of how it "broke") way...

Homework Statement The radiocarbon in our bodies is one of the naturally occurring sources of radiation. Let's see how large a dose we receive. 14C decays via Beta- emission, and 18% of body mass is Carbon. A) Write out the decay scheme of carbon-14 and show the end product. (A neutrino...

Nuclear decay and the "age" of atoms. All atomic nuclei heavier than hydrogen were created in stars and would therefore seem to have different ages relative to some specific spacetime reference. Nuclear decay wrt a single atom is taken to be a temporally random event, but is it plausible to...

(Apologies for cross-posting this in the Nuclear and Differential Equations forums. I'm new to posting on Physics Forums and not entirely sure where it belongs. Mods, please feel free to delete/move as appropriate.) I am trying to create a decay chain simulator in Excel that my pupils can use...

(Apologies for cross-posting this in the Nuclear and Differential Equations forums. I'm new to posting on Physics Forums and not entirely sure where it belongs. Mods, please feel free to delete/move as appropriate.) I am trying to create a decay chain simulator in Excel that my pupils can use...

I have been trying for quite some while but I can't seem to get this problem off the ground.1)Suppose that you hydrolyze 4.644 grams of a protein to form a mixture of different amino acids. To this is added a 2.80 mg sample of 14C-labeled threonine (one of the amino acids present).The activity...

What is the rate at which protons decay in vacuum? i don't mean radioactive decay, I mean the rate at which light looses intensity as it travels through empty space. Also, does this decay influence wavelength, sort of dropping the frequency down as light looses intensity? What causes...

can anyone please help me with the cluster decay defination

I suppose I should start out by confessing that I'm hopelessly ingorant on the subject of physics, so please, be gentle. :) My question is about the eventual decay of matter into...well, random subatomic particles, or iron...I can't recall what the theorie/s state precisely. But apparently...

Homework Statement In a chemica reaction the rate of consumption of a compound x is proportional to the square of the concentration of x. That is, dx/dt = -kx^2 where k is a constant show that x = 1/k(t-c)The Attempt at a Solution from my understanding usually i would try and find the...

Hi, I was wondering how I would find the speed decay of a ball rolling in a straight line, if i were to measure the time it takes to travel a certain distance over and over. i.e [FONT="Courier New"] >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> <---10cm--> <---10cm--> <---10cm--> ^...

Homework Statement c) In 420 days, the activity of a sample of polonium, Po, fell to one-eighth of its initial value. i) Calculate the half-life of polonium. Homework Equations The Attempt at a Solution if the activity fell by 1/8 then it went through 4 half liefs (1/2*4=1/8) so...

Are there any developed theories to explain why Muons and Taus decay so quickly, and why they don't stick around and leave us with x-ray emitting hydrogen atoms? It would be interesting if we could get them to last longer (I suppose relativistic speeds do, but that's still insignificant on the...

Estimate the decay heat rate in a 300 MWth reactor in which 3.2% mU-enriched U02 assemblies are being fed into the core. The burned-up fuel stays in the core for 3 years before being replaced. Consider two cases: 1. The core is replaced in two batches every 18 months. 2. The fuel...

One of the proofs that there was a Big Bang is the measurement of microwave backround radiation. It has been measured to be around 2.7 degrees kelvin and the explanation given why it's that the BB created a spectrum of frequencies and they have been stretched out by space expansion over time to...

Is it reasonable to expect muon decay to be slowed or stopped in electron degenerate matter like metallic hydrogen? The electron that would be the product of the decay would need to find a higher energy level. The effect may be analogous to the reason why a neutron is stable within a nucleus...

hello there! your help is really appreciated. 1.For the Ruther alpha-particle scattering experiment, how come we are only concerned with the nucleus of the gold with repulsion on the alpha particle? what about the electrons in gold? Don't they attract the alpha particle? 2. To calculate...

i understand that free neutrons are unstable and decay within about 10 mins, presumably because of the weak nuclear force would anti neutrons theorectically behave in the same way, or would anitmatter-matter chirality impact at all?

Homework Statement complete the following decay equations by inserting the missing particle or nuclide information. Identify each type of decay. see attached screenshot please. Homework Equations The Attempt at a Solution I've done all of the decays but we have to label them and...

Decay rate help I've been debating decay rates with another poster in another forum. Basically, the other poster has stated "The half-life/decay rate of the substances used in nuclear power generation have nothing to do with the generation of power. That they ARE radioactive is. Spent fuel...

Homework Statement Complete the following decay equations by inserting the missing particle or nuclide information. Identify each type of decay. i) 90?Sr = ?39Y + ? + ? ii) 22?Na = ??Ne + β+ + ? + energy iii)24294Pu = ??? + alpha + ? iv) 235?U =...

How can we prove that the mean life time of a radioactive decay is reciprocal to the decay constant?

Hi, I was just wondering if the vibrational energy levels in molecules decay, emitting a photon? or by some other mechanism? For example, if a laser is used to excite a vibrational mode (Like that in Stokes-Raman Scattering) from say v = 0 to v = 1 state. Will the molecule remain in the v...

Hi There, I have been working on fluorescence decays of the fluorophores whose lifetimes are comparable to the instrument response function(IRF) of my device. The technique I use is based on Time-correlated single photon Counting(TCSPC). I have been fitting the decay curves using...

muon decay constant/ muon flux where can i find the decay constant of a muon (the lambda which appears in): http://upload.wikimedia.org/math/3/f/2/3f28b1c0d4362b86a89f976d83d81070.png thanks edit: oh the wiki page http://en.wikipedia.org/wiki/Exponential_decay gives the relationship...

Hi, I am learning about analysing particles decaying and am on this Wikipedia article: http://en.wikipedia.org/wiki/Particle_decay Under the 'Two body decay' subsection, there is a description of the momentum of particles 1 and 2 from the rest frame of the parent particle. I have two...

I am answering a question about a particle decaying into two other particles and one needs to find the momentum of the children particles from the rest frame of the parent. I found a very helpful article on Wikipedia under 'Particle Decay', however I am really confused by their mathematical...

Homework Statement One could imagine that beta decay was due to a electron initially inside the nucleus and than leaving it. Proof by using Heisenberg uncertainty principle that this is not possible. There is a hint which says you can use energy spectra and values for the energy of beta...