What is Alpha: Definition and 474 Discussions

Alpha (uppercase Α, lowercase α; Ancient Greek: ἄλφα, álpha, modern pronunciation álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , which is the West Semitic word for "ox". Letters that arose from alpha include the Latin letter A and the Cyrillic letter А.

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  1. A

    Can You Safely Handle Alpha Radiation? The Dangers of Unprotected Exposure

    Say I were to pick up a big chunk of Americium-241. Could I just hold it in my hand or would it be painful? Not that I'm planning on doing it, just out of curiosity.
  2. G

    Exploring Alpha, Beta, Gamma Decay & Conservation of Mass/Energy

    I am completing an assignment that is covering alpha, beta, and gamma decay. I am going to try and keep this as general as possible, as I want to figure this out myself but I just looking for feedback to make sure I am on the right track. I noticed that after alpha decay, the mass of the...
  3. A

    Why aren't the daughter isotopes of alpha decay charged?

    For example, when a radioactive isotope of Uranium undergoes alpha decay, a radioactive isotope of Thorium is formed. Why isn't this daughter isotope charged?
  4. A

    Partial Fractions problem not matching Wolfram Alpha

    Homework Statement ∫10x-2x2/((x-1)2(x+3)) Solve by partial fractions. The Attempt at a Solution ∫A/(x-1) +B/(x-1)2 + C(x+3) after setting up the partial fractions and multiplying each term by LCD: 10x-2x2= A(x-1)(x+3) + B(x+3) + C(x-1)2 10x-2x2= A(x2+2x-3) +Bx+3B +Cx-C 10x-2x2=...
  5. Q

    How long would it take for an interstellar spaceship to reach Alpha Centauri?

    I'm writing a science fiction story and have a basic understanding of theoretical propulsion systems (ramjets, ion drives, solar sails, etc.). But I'm also trying to make my story plausible. So, that means no faster-than-light travel, infinite energy sources, artificial gravity generators, etc...
  6. C

    Practical Interstellar Mission to Alpha Centauri?

    Can this be done feasibly (with current/near term emerging technologies and sub-trillion dollar budget)? Assuming that the human race survives the 21st century, I think we'll have the resources for a multi-decade unmanned flyby mission to Alpha Centauri even if technology shows little progress...
  7. B

    Finding the Kinetic Energy and the Speed of an Alpha particle

    Homework Statement The nucleus of beryllium with mass number 8 decays into two alpha particles. The nuclear masses are M(8Be)=7456.6 MeV/c^2 and m(4He)=3727.4 MeV/c2. Assume that 8Be decays at rest and that we can neglect the atomic electrons. We are asked to find a) the kinetic energy of...
  8. Demon117

    Relationship between angle gamma and alpha and beta

    So I feel like a complete moron for asking this. I have never been very strong in geometry so I wondered if a few math folks could help me out. I am just looking for the angle relationships of gamma, alpha, and beta. This is just a small piece of a much larger analysis that I am doing. I...
  9. B

    Determining angle alpha with an elastic rope and a mass hanging from the rope.

    Homework Statement I am confused on how to begin finding the angles (theta) for answering part a?
  10. C

    Can beta radiation be detected in an expansion cloud chamber?

    Hello all, I just built an expansion cloud chamber and noted that while my alpha source (americium 241) produced a plethora of tracks, the beta source (strontium 90) produced no tracks at all-just mist. Does anyone know if beta radiation can be seen in an expansion type cloud chamber? Why or...
  11. G

    Magnetic field affecting an alpha and a beta particle.

    Homework Statement An \alpha-particle and a β-particle are both traveling along the same path at a speed of 1.5x106 ms-1. They then enter a region of uniform magnetic field. The field is a square with sides of 1 cm. The magnetic field is normal to the path of the particles and is into...
  12. A

    Spatial and temporal variation of alpha?

    Hi folks, In a followup to another thread about the recent controversial results by Webb et al. suggesting that the fine structure constant (alpha) varies across the visible universe, I was wondering: Assuming the Webb et al. results are correct (a big assumption), would we be able to say...
  13. W

    Hypothetical Planet in the Alpha Centauri System (Book research)

    I am writing a science fiction book that includes the idea of a planet orbiting within the habitable zone of Alpha Centauri A and I'm hoping this is a good place to get some questions answered. It's science fiction, so I'm perfectly fine with stretching the limits of possibility, here, just...
  14. J

    What is the method used to depict multiple alpha helices in protein structures?

    I have a question about one of the methods used to draw the alpha helix structures in proteins. This is a typical drawing from Wikipedia of a small protein transcriptional activator Myb; http://en.wikipedia.org/wiki/File:Protein_MYB_PDB_1guu.png Now that drawing looks typical of any...
  15. C

    Resonance & Triple Alpha Process: Why Does It Matter?

    Why does "resonance" greatly increase the likelihood of the triple alpha process? Why does the fact that the combined energy of 8Be and 4He is (almost) the same as the energy of an excited state of 12C greatly increase the probability of that reaction (i.e. 8Be + 4He → 12C + stuff) occurring...
  16. A

    Estimating Ion Pairs Produced by 5MeV alpha in UF6

    Hello, I'm attempting to work out the number of ion pairs produced by a 5MeV alpha particle in UF6 (in each of the solid, liquid, and gas states). Using the technique from my old radiation physics book (Turner 3rd ed) I should simply apply the Bethe formula -\frac{dE}{dx}=\frac{4\pi...
  17. C

    Why is alpha and beta radiation measured in Sievert?

    What's the point of measuring alpha and beta radiation in Sievert? As I understand it, one Sievert is an equivalent of 1 Joule absorbed by 1kg of body mass. But since alpha and beta radiation barely penetrate the human skin, most of the body mass isn't irradiated at all. So the dose in...
  18. 1

    How can I recognize H alpha line?

    Hi everyone! If I measure a galaxy spectrum in order to compute galaxy redshift, and I know that Balmer's H alpha line is evident in the spectrum, how can I recognize it? In other words, how can I be sure that the peaked line I clearly see on the spectrum is really H alpha line and not another...
  19. A

    Stupid question on Dirac alpha and beta matrices

    Homework Statement Dirac proposed that a relativistic wave equation that is linear in both space and time (unlike the Klein-Gordon equation, which is second order) has the form i\frac{\partial}{\partial t}\Psi = (\mathbf{\alpha} \cdot \mathbf{p)+\beta m)\Psi After squaring this, we'd like it...
  20. B

    What is the Force on a Proton in a 0.5 T Magnetic Field?

    Homework Statement A proton is projected into a magnetic field of 0.5 T directed into the page. If the proton is traveling at 3.4 × 10^5 m/s in a direction [up 28 ̊ right], what is the magnitude and direc- tion of the magnetic force on the proton?Homework Equations F = vBq(sin θ)The Attempt...
  21. J

    Bethe Bloch: Calculating ionisation energy losses for protons, alpha and muons

    Hi, this is my first post here. The forum seems like a great idea! I've got finals coming up in a few days and can't seem to get my head around this example and my tutor seems unreachable at the moment. Anyway, here it is: Homework Statement " A beam of particles contains protons, α particles...
  22. D

    Help with extracting alpha from: -alpha-asin(sin(alpha)(r/l)

    I am using the Law of Cosines to extract and angle I need from a shaft that is turning on an air engine by piston oscillation and I am having a brain fart on if there are any identities I am missing that can help me pull '\alpha' from the right side of my equation...
  23. P

    When to use alpha vs theta for angles

    Pretty simple question. When we draw triangles or other pictures with angles, when do we mark the angles as alpha and when do we mark them as theta? Is there some kind of convention or is it just whatever is free in the equation? It makes sense to me to use alpha for the first angle then...
  24. P

    Beta Rays: Electromagnetic or Nuclear?

    Are Alpha and Beta rays electromagnetic ? If yes, then how ? I would like to know how negatively charged beta ray comes from the nucleus ? Thanks !
  25. N

    Calculating Reverse Bias Voltage for Alpha Particle Detection

    Hi all, me again! :rolleyes: I'm trying to calculate the current created when an alpha particle strikes a silicon p-n detector, but I'm getting some strange numbers, so I was wondering if I was doing something fundamentally wrong... My problems start when I try to calculate the reverse...
  26. N

    Range of alpha particles in a silicon detector

    Hi, I'm trying to find the range of α-particles in silicon; I can work out the stopping power, \frac{dE}{dx}, but the reference I'm using then states that I need to integrate it as follows: R=\int_T^0 (-\frac{dE}{dx} ) ^{-1} dE The thing is, I'm not sure as to how to even start this...
  27. M

    The polonium isotope 210Po, an alpha emitter, has a half-life of 138

    Homework Statement The polonium isotope 210Po, an alpha emitter, has a half-life of 138.38 days. You happen to have a 1.5 g cube of 210Po, so you decide to use it to boil water for tea. You fill a well-insulated container with 120 mL of water at 18° C and drop in the cube of polonium. (a)...
  28. N

    Calculating the number of alpha particles incident on a detector

    Hi, firstly I'm not sure if I'm posting in the correct forum, if not could I request that the moderators move it to the right one. Ok, so my problem is pretty much as I stated in the title. The background to this is that I have been asked to roughly calculate the number of alpha...
  29. I

    Alpha Decay from Uranium: Electrical or Strong Nuclear Force?

    Hi, In case of alpha decay from Uranium atoms, i thought the barrier is the strong nuclear force, but i had seen many textbooks saying that it is electrical barrier, and i did rethink the subject and i imagined it as a barrier that have electrical force from one side and strong nuclear force...
  30. D

    Alpha particle and Beryllium reaction

    Homework Statement What is the equation for the reaction of a alpha particle and beryllium with production of one neutron Homework Equations Use an a chem equation The Attempt at a Solution The masses are 4 + 9 = 1 + x, so x = 12. The atomic numbers (protons) are 2 + 4 = 0 + x...
  31. D

    Kinetic energy of daughter nucleus and alpha particle from alpha decay

    Homework Statement In \alpha decay a nucleus X at rest decays to a daughter nucleus Y and an \alpha particle. Conservation of momentum and kinetic energy gives: M_{\alpha}v_{\alpha}+M_{Y}v_{Y}=0 \frac{1}{2}M_{\alpha}v_{\alpha}^{2}+\frac{1}{2}M_{Y}v_{Y}^{2}=Q Where the Q value is the...
  32. A

    Force of repulsion of alpha particle

    Homework Statement An alpha particle has a mass m = 6.64x10^-27 kg and a charge q = +2e. Compare the force of electric repulsion between two alpha particles and the force of gravitational attraction between them. Explain briefly why the gravitational force is ever significant, given its...
  33. D

    Hypothesis testing, why alpha cannot be zero

    Ok someone tell me the official explanation of why alpha cannot be zero in hypothesis testing.
  34. K

    Alpha particle touching Gold nucleus

    Homework Statement If the radius of the gold nucleus is 6.47 fm, and the radius of the α particle is 2.36 fm, then what is the minimum required kinetic energy for the α particle if we want the two nuclear surfaces to touch in a head-on collision? Homework Equations Ue=(kq1q2)/r The...
  35. S

    Electromagnetic forces, finding alpha.

    Homework Statement When a third charge is placed at the origin, it is found that the force on it is zero. Find alpha? Two charges Q and 5Q are located as shown in the figure below. https://chip.physics.purdue.edu/protected/GiordanoEMimg/chapter17/17prob16.jpg If possible, please...
  36. S

    Recurrence Relation for Alpha beta filter

    The alpha beta filter equation is given by this Xni = AXn + BXn-1 Xn-1 is subscript i want to figure the solution to this recurrence relation, but is it a recurrence relation? i am wondering weather alpha beta filters grow faster than exponential smoothing filters.- i said it is a 1st order...
  37. T

    Alpha Decay & Ionization: Modeling an Electron's Tunneling

    Hello, I'm trying to figure out if an atom undergoing alpha decay can knock out its orbital electrons. I was hoping someone might give me a hand coming up with a model to figure this out. What I need to figure out is: How far out does an alpha particle tunnel can I use a classical...
  38. S

    Alpha Magnetic Spectrometer 2.0

    (My apology if there already is a thread regarding the newly launched AMS-02, I didn't find it.) As I am sure most of you know the (second) Alpha Magnetic Spectrometer has been successfuly launched into orbit and is on its way to the ISS. I have two questions for any people here who are...
  39. A

    Alpha Particles: Is 'Radiation' a Misnomer?

    Isn't Alpha radiation a misnomer? Alpha particles are released during the decay of an unstable nucleus, their kinetic energy along with their charged nature have the ability to ionize other atoms. There is no radiation emitted. This is why alpha particles are only dangerous when relatively...
  40. P

    Finding the kinetic energy of an Alpha Particle

    Can anyone help with this problem? I think the solution may be simpler than I'm trying to make it. Colin measured the speed of an alpha particle that was emitted from a U-238 nucleus to be 2.20x10^8 m/sec. Calculate the kinetic energy of the alpha. Is all you need the equation KE = 1/2...
  41. I

    Atoms decay via alpha emission have a half-life of 150 min

    2.3 \cdot 10^{10} atoms decay via alpha emission have a half-life of 150 min. How many alpha particles are emitted between t=30 min and t=160 min? \begin{flalign*} 150 &= \frac{\ln 2}{\lambda}\\ \lambda &= 0.046 \\ \\ K &= K_{0}e^{(-\lambda)(t)}\\ &= (2.3 \cdot 10^{10})e^{(-0.046)(30)}\\...
  42. F

    Calculating disintegration energies of alpha emmision.

    Homework Statement (a) Calculate the disintegration energy when 232/92U decays by alpha emission into 228/90Th. Atomic masses of 232/92U and 228/90Th are 232.037156u and 228.028741u, respectively. (b) For the 232/92U decay in part (a), how much of the disintegration energy will be...
  43. D

    Finding Kinetic Energy of An Alpha Particle

    Homework Statement Problem: "Find the kinetic energy of an alpha emitted during the alpha decay of Rn-220. Assume that the daughter Po-216, has zero recoil velocity." Homework Equations Ei = Ef The Attempt at a Solution BE = Binding Energy, KE = Kinetic Energy (BE of Rn-220) = (BE of...
  44. A

    Reaction of alpha olefin sulfonate (AoS)

    Homework Statement Chemical reaction between alpha olefin sulfonate (AOS) and calcuim carbonate? I want to know the chemical reaction between alpha olefin sulfonate (AOS, RCH=CH(CH2)nSO3Na) and calcuim carbonate and also AOS with the following materials. 1.Anhydrite (CaSo4) 2.Barium...
  45. S

    Simple Alpha Particle Spectroscopy Question

    Homework Statement When detecting alpha decay with a spectrometer, why is it important to evacuate the chamber to create a adequate vacuum for where the source is place? Why is it better to place a radioactive source underneath a detector facing up rather than above the detector and facing...
  46. M

    Calculating Alpha Decay Energy for A=210, Q=5Mev

    Homework Statement if the decay of nucleuse with A=210, what is the alpha energy emited when the Q of the decay is 5Mev Homework Equations The Attempt at a Solution by energy and momentum conservation: parent=daughter+alpha decay+Q from the question the parent has A=210, in...
  47. S

    Beta or Alpha emitter nuclear fuel cycle?

    Do exist some proposed nuclear fuel cycle in which uranium or thorium whoud be first converted in some beta or alpha emitting isotope and after energy whould be harnessed with direct energy conversion methods?Possibly, it could reduce size of power plant and make steam turbine unnecessary.
  48. P

    Elastic collision of an alpha particla and Lead

    Homework Statement An a particle of mass 6.6 x 10-27 kg came closest to an atom of lead with a distance of 4.8 x 10-14 m. At what velocity will the a particle rebound directly away if the collision is totally elastic? Mass of the Alpha Particle - 6.6 x 10^-27 kg Alpha particles are...
  49. K

    Alpha particles as a fission product?

    Hello. Why isn't there alpha decay in fission reaction or fission fragments evolution ? is there only gamma and betas?
  50. K

    Explore Wolfgang Amadeus Mozart on Qwiki Alpha!

    Qwiki Alpha is a new web-site which is an online encyclopedia much like Wikipedia. It's very interesting, I actually prefer it to Wikipedia for concise and clear descriptions: http://www.qwiki.com/q/#!/Wolfgang_Amadeus_Mozart
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