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. G

    Basic physics question - alpha particle moving through B-field

    An alpha particle is moving in the positive x direction with a speed of 0.0050c = 1.50 * 10^6. When the particle is at the orgin, find the magnetic field at a) P3: x = 1.0,y = 1.0,z = 1.0 The book answer is r3 = sqrt(3) = 1.73 and vecto r3 from q to p3 and vector v form a plane that makes...
  2. Choisai

    Why are alpha particles most commonly emitted as helium atoms?

    As a physics student, I understand that α particles are emitted and are the same as helium atoms without electrons. But this raises two questions to me: 1) What happens with the electrons at the atom that emits them? He now has two electrons too much. What happens with those? 2) Why an...
  3. A

    Wolfram Alpha: all 2nd roots of 1

    I think a lot a users have vague concepts about the roots of unity. I try to post a link to WolframAlpha, which calculates all the second roots of unity http://www.wolframalpha.com/input/?i=sqrt%281%29 There you can see the input \sqrt{1} and the plot of all roots in the complex plane...
  4. sunrah

    Velocity of alpha particle within nucleus

    Hi, The decay constant for alpha decay is the product of the transmission probability P and the collision frequency f of the alpha with the potential barrier, where f depends on velocity of the alpha in the nucleus. My question is about this Hyperphysics page, where alpha decay is modeled...
  5. Crazymechanic

    Alpha particle confinement question

    A theoretical question , imagine we have a theoretical spherical confinement (don't tell me it;s not possible as I know that already :) ) Now we would set that spherical confinement to a high positive potential , inside it we would have a ionized gas , now the electrons would tend to distribute...
  6. teroenza

    Schools Using Wolfram Alpha to Evaluate/Compare Graduate Schools

    Hi All, I am looking into engineering and physics grad schools. I have a good deal of information available, and am trying to sort through it. Has anyone used Wolfram Alpha to do anythings like this? From basic comparisons like "Harvard University, Princeton University" it will give you a...
  7. M

    Radioactive Source Emitting Only Alpha and Gamma Radiation

    Homework Statement "How could you show that a radioactive source was only emitting alpha and gamma radiation?"The attempt at a solution This really stumped me...obviously they have different penetration distances, and different strengths of ionisation, but I don't know how to show that only...
  8. chisigma

    MHB A very strange statement from Wolfram Alpha....

    The so called 'Moebious Function' is a discrete function defined as... $$\mu(n)= \begin{cases} - 1 &\text{if n has an odd number of prime distinct fators} \\ 0 &\text{if n has one or more prime fractors with exponent greater than one}\\ 1 &\text{if n has an even number of prime distinct...
  9. Aab e Hayat

    How to Calculate Energy of alpha particle from its Activity

    I am given with the activity of alpha particle.How could i calculate its energy from it?
  10. B

    Four Protons Are Fused Into An Alpha Particle, Energy Released

    (answered)Four Protons Are Fused Into Alpha Particle, Energy Released Answered: I wasn't supposed to multiply by c2. Thank you ehild I apologize in advance if I posted this in an incorrect format or in the wrong section. I read the rules and I believe this is the correct format/place...
  11. O

    Analytically Solving Complex Expressions with Wolfram Alpha

    I'm noticing wolfram alpha has the amazing ability to analytically solve \sum_{n=1}^{\infty} \frac{1}{n^2 + a^2} Anyone know how to do this, and if it's also possible to deal with higher order guys (like it also can do 1/(n4+a2), but it's a way more complicated expression to the point...
  12. Y

    Radioactive nucleus - why is alpha emitted and not proton

    So I recently heard of a simple way of thinking about how the emission of an alpha particle is "beneficial" to a nucleus being stable. The argument goes as follows: "Let's say we have a nucleus that is unstable because the electric repulsion of protons can't balance out the strong force...
  13. Y

    How long would it take to get to Alpha Centauri?

    So Alpha Centauri is about 4.37 lightyears from earth, but that's in Earth's frame of reference, if you could build a spaceship to go, say 9/10c relative to Earth how long would it take to get to alpha centauri, because then space-time would be warped and therefore it would no longer be 4.37...
  14. C

    Confused about answer wolfram alpha spat out to me.

    Homework Statement Ok well I had a real nasty equation in which i could not solve. I used wolfram alpha to get out this answer "theta ≈ 0.74559 + 6.28319n for integer n". can someone please tell me what this statement means. do i assume theta in degrees equals 0.74559(180/pi)...
  15. K

    Find the kinetic energy of the alpha particle

    Homework Statement For the decay " Uranium-232 ---> Thorium-228 + alpha particle ", What is the alpha particle's kinetic energy in the U-232 atom's rest frame? We are given the masses for each one. Homework Equations E = mc^2 The Attempt at a Solution I tried mass(U-232) -...
  16. R

    Alpha and beta radiation interaction

    Before I sound stupid I am only at GCSE level (high school in America) so understanding is little. But theoretically could an alpha particle (helium nucleus) gain electrons and become a helium atom. If this is possible can it be done with two beta particles? Correct me I in wrong an explain why...
  17. J

    Calculating Current of Alpha Particle Beam

    Homework Statement If a beam of 9.39 x10^20 alpha particles passes a given point in 1.50s, what is the current? Homework Equations I=q/t The Attempt at a Solution umm the answer is 2.00 x 10^2 A, not sure where to begin. Would be a great help if someone can point me to the right...
  18. jim mcnamara

    Handwritten answers from Wolfram Alpha

    http://blog.wolframalpha.com/2013/04/01/introducing-the-wolframalpha-handwritten-knowledge-engine/ Hmm. Could this be an April Fools Day exercise?
  19. A

    Alpha decay potential barrier.

    Homework Statement A nuclei of a atomic number Z decays into a alpha particle (a He nucleus with Z =2) and a daughter nucleus with (Z_{d}). The decay may be described as the tunneling of an alpha-particle through a barrier caused by the Coulomb potential between the daughter and the...
  20. E

    Suppose an electron was kept with an alpha particle at a finite

    Suppose an electron was kept with an alpha particle at a finite separation x. Why does it have a negative potential ENERGY ... In other words, what does a negative electric potential energy mean? I want an answer relating it with potential energy at infinity which is zero. Secondly, if the...
  21. S

    Can't Seem to Solve Alpha: Find the Limit

    See attached image. Can't seem to get alpha to compute this. Had this in a test and it stumped me. Could someone explain how to find the limit? Thanks in advance guys.
  22. S

    Statement about Forbidden Alpha decay transitions.

    Hi, I'm confused about a statement about the change in final/initial states of the daughter/parent atom in an alpha decay. It is the following; "The spin between the parent (I_i) and daughter (I_f) can change by lh (h being h-bar, l is the orbital angular quantum number of the alpha particle)...
  23. G

    How do I determine the half life of an alpha particle?

    I am fairly new to nuclear chemistry and I was just curious as how to find the half life of a helium nucleus. Would it be the same as finding the half life of 1 neutron x2 and 1 proton x2? Or is this the completely wrong way to do this. Also would the half life be the same as a helium atom or...
  24. R

    More observed Beta sheets than Alpha helices as temperature increases

    From an experimental study I've found that alpha helices are formed more often than beta sheets when the temperature is low, but when the temperature increases the beta sheets becomes more common. I'm trying to figure out why. As temperature increases, the outer hydrogen bonds of a structure...
  25. D

    Where to find an alpha radiation silicon detector? (alpha spectroscopy)

    I am looking for an alpha detector to do an alpha spectroscopy (and maybe beta as well). The rough setup is a vacuum tube with a detector in one end and a source in the other, possibly with a magnet in the middle. I have googled around, but my problem is that I don't really know what is...
  26. C

    Potential Alpha source material

    Hello Physics Enthusiasts The other day I received in the mail a uranium ore sample from United Nuclear, with a radiation measurement of 2,500cpm, intending to use it as a particle source for my replication of the famous Gold-Foil experiment, the theory for which was devised by Ernest...
  27. J

    Inelastic Scattering of alpha particles on a target.

    Homework Statement It is desired to study the low-lying excited states of 35Cl (1.219, 1.763, 2.646, 2.694, 3.003, 3.163 MeV) through the 32S (alpha,proton) reaction. a) With incident alpha particles of 5.000 MeV, which of these excited states can be reached? b) Again with 5.000 MeV incident...
  28. nomadreid

    Shortcut for alpha =5% in a two-tailed test

    If I adopt a level of significance of 5% for data which is normally distributed, and I am adopting a two-tailed test, then I see no reason to mess with standardizing my data and looking at the probability tables, but rather to simply reject anything outside of two standard deviations away from...
  29. M

    What is the Effect of Heat on Alpha Particles in a Closed Box?

    Ok, so I am currently building a cloud chamber for a major presentation in the area of Thermodynamics (or Energy and Temperature) and I've been thinking quite a bit about this theory...and i could be wrong...so don't tell me off about it... So the general physics of a cloud chamber, Isopropyl...
  30. Z

    Calculating Alpha in BJT Common Emitter Circuit

    i have been asked in my lab report to calculate alpha in a bjt common emmitter circuit using 2 different formulas and explain why one is misleading.β=Ic/Ib= 537.1*10^-6/6.743*10^-6≈85 α= Ic/Ie=573.1*10^-6/566.357*^-6≈1.011 α=β/β +1≈0.988 i have worked out the two values of alpha where our beta...
  31. M

    K alpha and K beta wavelengths

    Homework Statement Calculate the Kα and Kβ wavelengths for He and Li Ive seen https://www.physicsforums.com/showthread.php?t=118050 and the two websites that were given for tables, but I need to show calculations. Homework Equations K alpha Energy=10.2eV*(Z-1)2? E=hc/λ The...
  32. D

    Collisions of electrons and alpha particles

    What would happen if one were to fire electrons at a solid mass of alpha particles?
  33. W

    Alpha Particle Elastic Collisions

    Homework Statement A proton strikes a stationary alpha particle (4He nucleus) head-on. Assuming the collision is completely elastic, what fraction of the proton’s kinetic energy is transferred to the alpha particle? Homework Equations Pi = Pf Ki = Kf The Attempt at a Solution For...
  34. Drakkith

    Planet Found Orbiting Alpha Centauri

    From here: http://blogs.discovermagazine.com/badastronomy/2012/10/16/alpha-centauri-has-a-planet/
  35. S

    Alpha and beta particles in gas ionization

    Hello, why alpha particles are better at ionizing gases than beta particles ? shouldn't the negative particles repel more electrons ? thanks
  36. D

    MHB Solving for alpha and beta

    \begin{align} \alpha_nb^n +\beta_nb^{-n}=A_n\\ \alpha_na^n +\beta_na^{-n}=C_n \end{align} How does one go from that to $$ \alpha_n = \frac{A_n/a_n - C_n/b^n}{(b/a)^n-(a/b)^n} $$ and $$ \beta_n = \frac{a^nC_n - b^nA_n}{(b/a)^n-(a/b)^n} $$
  37. R

    Does air pressure affect the range of alpha particles in air?

    Homework Statement We have an alpha particle moving in the air (p=10^5 Pa). Its range is "d". What would be the range if the pressure was q=10 Pa only. Homework Equations x=d*(p/q) ? The Attempt at a Solution I think the particle is slowed down the more the more is the number of...
  38. X

    Alpha decay vs 12C emission

    Homework Statement Radium 226 usually decays via three consecutive alpha decays into Pb 214. Show that energetically possibly for radium 226 to decay into 214|86 Pb and 12|6 C but tell why it is highly unlikely. Calculate the lifetime of the direct transition as a function of the possibility...
  39. D

    MHB Why is alpha mentioned in the cooling process equation?

    Why is $\alpha$ mentioned? I don't see an $\alpha$.With proper non-dimensionalization and assuming for convenience that the ratio of convection and conduction parameters $h/k = 1$, the cooling process is described by the following equations: \begin{alignat*}{4} T_t & = & T_{xx} & \\ T_x(0,t) &...
  40. S

    Medical What is the role of alpha 2 receptors?

    Hello everyone, Ok my textbook says inhibition of transmitter release, vasoconstriction and more things. Now my question is what does inhibition of transmitter release mean. Since alpha 1 receptor is present on post synaptic membrane, and alpha 2 is present in pre synaptic membrane, does this...
  41. V

    How to use wolfram alpha to plot frequency response

    Can someone please tell me how I can plot the magnitude and phase response of this transfer function on wolfram alpha as I don't have Matlab: H(s) = -(2.1953*10^12)/(66600*((j*ω)^2)+808823539.4*(j*ω)+2.1626*10^12) A link to the output would be very useful also, thanks heaps.
  42. A

    Alpha ray scattering experiment

    I have some basic doubts in the alpha ray scattering experiment by Rutherford and his students way back in 1909. 1.In the formula for the distance of the closest approach, the term velocity of the alpha particle and the charge of the gold nucleus appears. How did they measure the velocity of...
  43. Eirhead

    I have a spacecraft that can trave to Alpha Centauri in 1 week

    Am I going to absorb 4 years of light data from Alpha Centauri or is it just going massively blueshift?
  44. S

    The effects of the alpha, beta and gamma radiation on humans

    I have had a great deal of trouble finding sources that are specific as to how exactly radiation damages the body, it usually just says what damage radiation causes but not how it causes it, so I have compiled what I have found and I want to know if it is accurate and to fill in sequence of...
  45. X

    Worth paying the extra money and upgrading to Wolfram Alpha pro?

    Do you guys think it is worth paying the extra money and upgrading to Wolfram Alpha pro?
  46. S

    Converting Speed: Alpha Particle Velocity to Miles/Hour

    This is not a homework question, but it is from a book... The book asks: In a nuclear chemistry experiment, an alpha particle is found to have a velocity of 14,285 m/s. Convert this measurement into miles/hour. I want to verify the correct way to do this, and I also have a question about...
  47. G

    Calculate a vector wich forma an angle alpha with another vector

    Homework Statement Looks very simple, but I need help. I have a 2D vector, v, and I need to calculate a vector which forms an angle \alpha with it. Thank you very much Homework Equations I think that the equations should be, for 2 given vector u and v: thanks
  48. N

    An alpha particle is fired at a uranium atom

    Homework Statement "If an alpha particle is fired straight at the nucleus of an uranium atom (q = 92e), at a velocity of 5 x 10^5 m/s, how close will it get to the uranium nucleus? Homework Equations Ek = (mv^2)/2 Ee = (kq1q2)/d The Attempt at a Solution Since the alpha particle and...
  49. E

    Why is an alpha particle high ioniser

    What is the main cause that alpha particle has the highest ionisation out of the beta and gamma... Is it because of it's LARGE MASS or LARGE MAGNITUDE OF CHARGE?? This leads me to the general question.. How does ionistation occur and what affects it.. Mass or CHarge??
  50. Q

    Radioisotopes: Alpha, Beta, Gamma Emissions?

    I need to question that what does radio isotopes emits?Alpha,Beta,Gamma or all particles?
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