Beta Definition and 403 Threads

  1. E

    Emission of Gamma and Beta rays : Experimental Problem

    Hi there! The experiment: I'm counting Gamma and beta rays emitted from gamma and beta cylindrical sources, for counting I'm using a simple GM counter, which has nearly the same cylindrical shape (i mean diameter). As we all know this are electromagnetic emissions, so they distance must...
  2. M

    Is the Beta Decay Mass Condition Dependent on Atomic Masses?

    In beta decay, positron emission, how come the condition for decay is: M_p > M_d + 2m_e Thats: atomic mass of parent > "daughter + twice the mass of an electron. I'm sure there is some simple way of showing it, but I can't seem to find it! Also, is the most stable isobar on an atomic...
  3. C

    Mass/charge balance of Beta decay/nuclear reactions

    Homework Statement There are three different reactions we did in class. B-: 6C14 --> 7N14 + e- B+: 6C11 --> 5B11 + e+ Nuclear rxn: alpha particle + 7N14 --> 8O17 + e+ Homework Equations Q tot = (mass inital - mass final) * 931.5 MeV Charge balance The Attempt at a Solution In...
  4. E

    Beta Decay not a specific problem, just a question

    I understand that a beta plus decay emits positron and beta minus decay emits electron. For the calculation of kinetic energy of the particle released, you take into account the mass of electron for beta plus, but why is it that you DON'T take into account the mass of electron for beta minus? I...
  5. D

    How does one integrate for positive beta and real b ?

    How does one integrate \int_0^\infty e^{-\beta x^2}\cos{(bx)} dx for positive beta and real b ? I was thinking maybe differentiation under the integral sign would do the trick, but I can't get anywhere.
  6. S

    Beta function and changing variables

    Homework Statement \int_{0}^{3}\sqrt[3]{\frac{3-x}{x^2}}\: \mathrm{d}x 2. The attempt at a solution I'm pretty sure I have to use Euler's Beta function, so I tried to change the limits to 0 and 1 by setting x = 3·u (so dx = 3·du). However there must be some mistake when I did it because I...
  7. F

    Probability of Beta Particle Detection from Uniformly Covered Surface

    We have a surface that is 10 cm x 10 cm. That surface is uniformly covered with a radioactive material. When radioactive material decays, it has a equal probability of emitting radioactive particles, in this case beta particles, in any direction (360 degrees). We have a detector that...
  8. M

    How Many Beta Phases Are Involved in Turkish Cymbal Making?

    I am researching Turkish cymbal making technology and I discovered and learned that they made in beta phase. Beta phase comes within % 23 to % 25 tin ratio and 625 to 780 - not exactly , you must look to diagram - degrees heat. I found few phase diagrams and it seems to me there is only one...
  9. A

    The antineutrino in Beta decay

    I understand the physical changes in beta decay that eventually lead to the virtual particle, a W- boson being formed. However I do not understand the physical changes that take place, which eventually lead to an antineutrino being emitted. What changes take place in the W- boson, that make it...
  10. K

    Supremums 'alpha' and 'beta' problem

    Homework Statement Let A, B,be two non empty sets of real numbers with supremums 'alpha' and 'beta' respectively, and let the sets A+B and AB be defined by: A+B={a+b / a belongs to A, b belongs to B}, AB= {ab / a belongs to A, b belongs to B}. Show that alpha+beta is a supremum of A+B...
  11. matt_crouch

    Beta Decay & Quarks - A-Level Physics Explained

    In my A-level Physics course we have been talking about nuclear decay. When an nucleus decays by beta emission the proton number increases. My teacher described a neutron as "an electron and a proton" so that the overall charge is 0. To me this sounds like a simplification. what's really going...
  12. liometopum

    Beta Decay Neutron: Proton, Electron Mass Difference

    Here is a beta decay related question: Masses are from Particle Data Group (http://pdg.lbl.gov/2008/listings/contents_listings.html) Neutron has udd quarks. Mass is approximately 2.5, 5, 5 MeV. Total 12.5 MeV Products are: 1. Proton. uud quarks. Mass approx 2.5, 2.5, 5 MeV 2. Electron...
  13. J

    Why does Z=-1 for a beta minus particle?

    This sounds like a silly question but if Z (atomic number) is defined as the number of protons in a nucleus. Why does Z=-1 for a beta minus particle? (since it is just an electron) I know what is happening with the decay that a up quark turns into a down quark so that a neutron turns...
  14. J

    Boson and electron mass and speed in beta decay

    My first post - Hi everyone. I've been reading about boson mass and speed for a couple of hours but I can't seem to find answers. - What is the speed of the W boson during beta decay? If it has a huge mass shouldn't it be a lot slower than leptons? - I assume the electron and...
  15. I

    Exponential Attenuation and Beta Particle Range

    Exponential Attenuation and Beta Particle Range (solved) Homework Statement I am given a beta emitter and its atomic mass, as well as the atomic mass of its daughter, which have a difference of 0.0034 amu. I am to determine the range of the particles in air. Homework Equations I am given...
  16. E

    Penetrating power of a beta particle

    Hello! I've been quite puzzled by this question and its solution. Explain why beta-particles penetrate through matter more easily compared with alpha-particles having the same KE? The answer given goes: The mass of beta-particles are much smaller than those of alpha-particles, hence the...
  17. D

    How to Accurately Measure Backscattered Beta Particles?

    I am designing an experiment to investigate how the number of beta particles scattered backwards depends on the thickness of a foil and the proton number of the foil material.I have decided on the source Sr-90 for beta emissions.i know what to do to. I will have the beta particles fired at the...
  18. L

    Finding E(X^2) for a Beta Distribution

    Homework Statement The actual question I'm working on is to find the Method of moments for \theta for a beta distribution where the parameters are m = n= \theta Homework Equations What I need help with is to get started, I know that E(X)=1/2 for this question so that it does not...
  19. K

    Minimum Energy Of A Beta Particle

    Homework Statement When Ne (Z=10) decays to Na (Z=11), what is the maximum kinetic energy of the emitted electron? What is the minimum energy? What is the energy of the neutrino in each case? Ignore recoil of the daughter nucleus.Homework Equations E = mc^2 The Attempt at a Solution The...
  20. P

    Ionizing particles (alpha & beta)

    I think I understand the impact that an alpha particle can have on living tissue. Not having electrons in it valence it would be very reactive - stripping electrons from atoms or molecules it bumps into (assuming it made its way in a biotic host). But how does a beta particle ionize an atom...
  21. P

    Radioactive Decay - Beta Particles

    One thing that is really confusing me is Beta Particles. This site states that Beta Particles are electrons that are shot out of the nucleus (atomic core) of an atom. http://home.clara.net/darvill/nucrad/morebeta.htm To rationalize this claim it states that a neutron will decay to a...
  22. A

    The antineutrino in beta decay.

    Hello fellow physicists and mathematicians! I am 15 years of age and trying to understand beta decay. At present I understand how the proton turns into a neutron etc... The problem is I do not understand how the decay of a W- boson turns into an antineutrino. I've read that the W- boson has...
  23. V

    Another question about beta decay (stupid ones)

    A couple of really stupid questions:( In beta minus decay, an atom release and electron (and an antineutrino). The electron, does this happen spontaneously? Doesn't the another particle have to collide or interact with the atom (be give it some momentum, or energy), to trigger the atom to...
  24. V

    Beta Decay: Why Isomeric State Has Long Half-Life

    Please look at the attached file. The first part of the question: why it doesn't decay to the GS. I think that's simply because the nuclear spin changes by 4 and therefore this decay is very supressed. But how "is it possible for the isomeric state at 140kev which decays by gamma emisson, to...
  25. H

    Can You Explain Beta Minus Decay and its Relation to Neutrinos?

    [SOLVED] beta minus decay? Hi, Here is a question from beta minus decay which i could not understand : http://img360.imageshack.us/img360/2512/59060072re9.jpg I could do the first bit but not the second. I believe that it has something to do with neutrinos and missing energy but i...
  26. N

    Beta Decay Problem: Solve KE of Recoil Nucleus

    Homework Statement Consider a beta decay: \ {X_Z^A} \rightarrow\ {Y_{Z+1}^A} \ + {\beta_{-1}^{0}}\ + {\bar\nu_e} To show that the KE of the recoil nucleus is \ E = \frac{\ Q + \ 2 \ m \ c^2}{\ 2 \ M_Y \ c^2}\ {T_{max}} m and T(max) is the mass and maximum KE of beta particle...
  27. P

    Understanding Beta Particles and Their Role in Radioactivity | Diagram Included

    Hi! I read in my textbook, that when there is beta radioactivity, the beta particles are "carrying" the kinetic energy from the nuclei, and they are taking the most of the kinetic energy of the nuclei, so the electrons have less energy than them... Here is diagram. I can't understand something...
  28. S

    What is the electron and beta rays?

    Hello, I have got a assignment... there is a question what is the electron and beta rays? i have searched a lot but i cannot undersatnd it..can someone please explain me..I shall be thankful to you.. regards, samar
  29. M

    Beta Function: Prove (m-1)!/n(n+1)...(n+m+1) for m+ve Int

    Homework Statement Show that β(m,n)= (m-1)!/n(n+1)...(n+m+1) where m is a +ve integer ? Homework Equations The Attempt at a Solution Please give me a complete solution as i i asked it before but could not arrive at the solution ?
  30. manjuvenamma

    Vector of magnitude m making angles alpha, beta and gamma with i,j,k

    Many of us have seen how to find a vector satisfying the following conditions (i) magnitude is m (ii) makes angles alpha, beta and gamma with i,j,k vectors i.e. unit vectors along x,y and z axes. My question is can the angles be taken arbitrarily or they should satisfy some condition like...
  31. hagopbul

    Exploring the Fate of Beta Particles in Space

    If I have to send a beta particle in space and if the space is completely empty (from matter and energy just imagine!) What would happen to the particle? If I put a very good GM in 1 Km from the source should I detect the beta particle if the beta particle has the power of 0.5 Mev? Dose the...
  32. B

    Why do some heavy elements prefer beta decay over other forms of decay?

    Can anybody explain me the conditions for become a beta decay. for example : Md (Z=101,A=255) --> No (Z=102,A=255) + e (electron) + -Ve (anti-notrino) can this nuclear reaction be?
  33. P

    How Does Layering Affect Beta Particle Penetration and Energy Loss?

    If we want to secure an area from beta particles, we could use absorbers, for example aluminum foils. Is it preferable to use one thick aluminum foil or several aluminum foils (with same total density as the first one of course) with free space between them? In other words, does a beta particle...
  34. P

    Does Gravity Affect Beta Particle Absorption in Aluminium Foils?

    Suppose a beta particle source. Using a G.M. scintillator and several aluminium foils we can find the absorption of aluminium on beta particles. Does the absorption of aluminium changes by placing aluminium foils over or under the radioctive source? Considering for example gravity. Does gravity...
  35. S

    Exploring Beta Minus Decay: Neutrons to Protons Conversion in Unstable Nuclei

    unstable nucleus with excess neutrons turns to protons, emitting electrons and electron antineutrinos,in this case protons stay in nucleus...is there any case where protons are also emitted ...
  36. E

    Difference between beta and electron particle

    hi.. we all know a electron and a beta patricle have charge -1e .. now my question is.. when radioactivity takes place ..the nucleus emits beta particles sometimes... now can we say that the electron is being emitted from the nucleus..since both beta and electron have the same charge...
  37. J

    Beta Decay, how can baryons produce Leptons ?

    Hey I know : n = p+ + e- + (Ve) meaning that : p+ = n - e- - (Ve) = n + e+ + Ve ?? But, how does a Baryon like a proton or a neutron produce leptons ? and how this change can occur : n = p+ + e- + (Ve) u d d = u u d + e- + (Ve) How can a down quark become a Up...
  38. A

    Lepton beta decay when m near m_W?

    lepton beta decay when m near m_W? Has anybody seen somewhere, article or textbook or website, the calculation of beta decay of a charged lepton in the generic case, when mass is neither a lot smaller nor a lot greater than the mass of the W? It should be some result interpolating between the...
  39. P

    Beta Threshold Energy: Electron vs Positron

    This has been annoying me since I read this somewhere. Beta decay is only possible if energetically allowed. For electron emission this means: [M(A,Z) - M(A,Z+1)]c^2 >0 For positron emission this is [M(A,Z) - M(A,Z-1) - 2m_e]c^2 >0 Why the asymmetry? I would naively think that...
  40. W

    Beta particle counting efficiency?

    Beta particle counting efficiency?? Hi! Can anyone tell me what counting efficiency means? For example if it's put into a question as: "shielded beta counter with 85.7% counting efficiency, 845 counts are accumulated in one week" what does it mean? How I understand it so far is that it's...
  41. S

    Double Beta Decay: Questions from a Newbie

    I am new to this forum and hoping all you experts here can help explain some things that have been bugging me. In a double beta decay (any kind, with or without neutrinos), I read that the decay occurs from two separate neutrons, apparently simultaneously. Is this the case, or can one...
  42. D

    Beta Decay Curve: KE Not Constant?

    Hi all, Why is the beta decay graph( no. of Beta particle vs Kinetic energy) a curve(or sort of bell shape). I understand that neutrinos are emitted, even so shouldn't the KE be a constant value? Thanks
  43. Y

    How Does a Down Quark Transform Into an Up Quark During Beta Decay?

    for beta decay n --> p + e- + antineutrino since neutron has quarks udd while proton has uud, only the d changes to u. is it correct to guess that it is the down quark inside the neutron which "transform" into up quark? ie d --> u + e- + antineutrino
  44. S

    What physically is the BETA of a transistor?

    Hi All, The question I ask is pretty elementary.Come to think of it, i am not even an academic and the industry I work in is different. The BETA of a transistor. What is it in physical terms. How do the manufacturers of the transistor decide how to put that beta into it,physically.Does it depend...
  45. mattmns

    Should You Join Phi Beta Kappa or Phi Kappa Phi?

    What do you all think of college honor societies? Specifically, Phi Beta Kappa, and Phi Kappa Phi? Are these things that should definitely be accepted? Or is there really no point to them? Thanks!
  46. U

    Prove torque equation 2sin^2(theta/2) * cos(theta + beta) = sin (beta)

    Homework Statement A uniform smooth plank weight W and length 2a is hinged to the bottom horizontal edge of a smooth, fixed plane inclined at angle (beta) to the horizontal. A sphere of radius (1/2)a and weight 2W is placed between the plank and the plane. Assume no friction. Prove that, in...
  47. Z

    Beta Disintegration: Nucleus Absorbing Electrons & Positrons

    I was studying Beta decay in my nuclear courses few minutes ago, and something came to my attention. A nucleus can absorb an electron and undergo a beta decay like this: p + e- ----> n + neutrino Is the following one possible? n + e+ ----> p + anti-neutrino? where a nucleus absorb an...
  48. X

    Can the Beta Distribution be Adjusted to Range from -A to A?

    I have is a distribution that is U-shaped, centered at 0, spanning from -A to A, and I want a means to model this, a beta distribution is the closest thing I have found to kinda do this can the beta distribution be adjusted to range from -A to A as opposed to 0 to 1? any other suggestions as...
  49. A

    Understanding Fermi Theory of Beta Decay: A Comprehensive Guide

    What is the best textbook or article that really indepth explains the fermi theory, including derivation of the fermi golden rule and a good discussion of fermi functions? Most nuclear physics textbooks I have looked through seems to skim over the details :frown:
  50. R

    Why Does She Avoid Eye Contact After Our Great Conversation?

    WTF GIRLS please help! Well I am in the first (university) year, so i met a girl called "beta". So i introduced myself to beta and we talked like 1 hour and she laugh, etc. so we had a good conversation. And in the next days, we crossed sometimes in the path, and she just go away without...
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