Emission Definition and 546 Threads

I_A=BT^2e^{-\frac{e\varphi}{k_BT}} We measure T and I_A and from that get work. If T_0 is first temperature in which we measured than we get \frac{I_A}{I_{A0}}=\frac{T^2}{T^2_0}e^{-\frac{e\varphi}{k_BT}(\frac{1}{T}-\frac{1}{T_0})} And from that we get...

For this question I am considering a slit diffraction experiment set up as follows: {Monochromatic source} ------> {Single slit} ------> {Diffraction grating with N slits} ------> {Screen with small movable detector} The monochromatic light source emits photons one at a time. The principal...

in an experiment we looked through the diffraction grating to see the spectrum made by a helium lamp. we measured the distance along the meter stick to the point where we saw each color. based on that distance how would you calculate the wavelength of the light that was seen? would you...

Homework Statement A 67-Zn nucleus is at rest and in its first excited state, 93.3 keV above the ground state. The nucleus then decays to the ground state with the emission of a gamma ray. (One atomic mass unit is 931.5 MeV/c2.) What is the recoil speed of the nucleus? (You can assume...

Hi! This is a very basic question. How do I calculate the total probability for a certain gamma of a decay? For example, I know from empiric method that the 2 gammas from Co60 have a probability of 50%. But for Eu152 I have lots of gammas and I need to compute them all in a simulation program...

I have a question regarding Child's Law with thermionic emission. I understand that due to space-charge effects, that the emission current from a cathode reaches a saturation current at a certain temperature, explained mathematically by Richardson's Law. Utilizing an accelerating positive...

A gas composed of hydrogen atoms in the ground state is bombarded with electrons of energy 12.5eV. a) What wavelengths emitted can we expect to observe? b) If we replaced the incident electrons with incident photons of the same energy, what would happen? I know the answers to both...

Physics.org: March 10, 2010 By Lisa Zyga Hans-Otto Meyer, a physics professor at Indiana University has shown that the electron firings are distributed in time, in burst patterns, but in a "peculiar, correlated way", he believes the correlation involves some kind of trapping...

I was just wondering if anyone knew of anywhere on the internet that had a list of all known emission spectrums of the elements. Thanks!

In a gas laser, an electron in the highest energy state absorbs photon for stimulated emission to occur, but now since it has more energy than its highest state, shouldn't it escape the atom and the active medium be left only with positive ions?

Hello, I seem to be having a problem with an assignment :confused: : I need to calculate the electric field at which optical phonons will be emitted. Here's what I have been given: Semiconductor with effective mass m=0.26*m0. The optical phonon energy is 50 meV. The mean scattering time...

Homework Statement Light of wavelength 411 nm is emitted from a hydrogen discharge. What transition produces this emission? a. k = 5 to n =1 b. k = 4.5 to n = 2 c. k = 2 to n = 6 d. k = 2 to n = 3 e. k = 6 to n = 2 Homework Equations R = (1/n^2 - 1/k^2) The Attempt...

Why does a hot object emit Infra red light. How are photons are emitted from it?

Homework Statement A radioactive source emits electrons. The number of electrons emitted per second N(t) decreases with time according to the equation: dN/dt = −1.8 × 10−5N(t) , where t is expressed in seconds. If N = 12 electrons/sec at t = 0, after what time t has N fallen to the value...

Homework Statement Monochromatic light of wavelength 4.5 x 10-7 m will eject electrons from the surface of a metal with a maximum KE of 3.2 x 10-19 Joules. Will light having a wavelength of 6.8 x 10-7 m also cause emission of electrons from this metal Homework Equations E = h.c/lambda...

In papers presented this week to the American Astronomical Society, Andrea Schmidt and John Singleton of Los Alamos National Laboratory provide detailed analyses of several pieces of observational data that suggest that pulsars emit the electromagnetic equivalent of the well-known "sonic boom"...

Happy New Year to all you Physics Geniuses out there! I have a question concerning how the optical emission spectrum of a gas would be affected by being dissolved in water. I know very little about spectroscopy so please forgive me if this seems like an idiotic question. Let's assume I...

I have been trying to picture the whole process of a photon emission by a atom. So to have good understanding what is going on, I have came up with following experimental setup. A single hydrogen atom in excited state ^2\!P_{1/2}, which has been orientated with a magnetic field so that...

the question states that the emission spectrum of hydrogen contains a line with wavelength 656.2nm. and we need to approx find out what temp the H gas needs to have to be heated before this line appers in the spectrum i have worked out that for this wavelength the electron mov from level 3 to...

Hello, Does anybody know if there has ever been an emission spectrum of Earth recorded by one of our spacecraft s after launch from outer space? When we directly image extrasolar planets we are able to determine their atmospheric properties, etc, so can someone point me to a link which...

Homework Statement A planetary nebula is larger when imaged in H\alpha than when observed in a Helium line, Why? Homework Equations The Attempt at a Solution I understand that a planetary Nebula gives an emission spectrum and that If the nebula looks larger in a H line there is...

Homework Statement When a hydrogen atom undergoes a transition from the n=2 state to the n=1 level, a photon with \lambda=122nm is emitted. a)If the atom is modeled as an electron in a one-dimensional box, what is the width of the box in order for the n=2 to n=1 transition to correspond...

It is known that for light of a given intensity when incident on a photoelectric material, the number of electrons emitted is independent of the frequency of light, but increases when the intensity of light goes up. However, the maximum kinetic energy of the emitted electrons increases with the...

I've seen much mention in websites of matt black surfaces being better emitters of infra red than shiny silver ones so if a matt black and shiny silver surface are heated to about 100 deg C the black one will cool down more quickly as a result of this! Doesn't Wien's law state that the amount of...

Hey all, I have a lab coming up that deals with the emission spectra of H, He,Ne,Hg, and N_2 I am looking around for some sources to compare my results to, and I thought I would post here in case anyone knows of a good (preferably online) journal article or reputable website that would...

Hi. I can't see why the photon created by stimulated emission in a common laser should be in phase and with the same polarization of the original photon. Thank you.

I am a newbie to the forum and impressed by the breadth and depth of the material here. After searching I am unable to answer a question that I have been pondering. One of my brightest students asked whether electrons other than the valence electrons were involved in the emission spectra of...

I have been wondering lately, as I am quite new to physics. If an atom dropped from it's first energy level back to it's ground state, and emitted a photon. Could a photon of the same wavelength excite the atom back to it's first energy level? What is the difference between emission and...

Hey all, I am just wondering if one can directly calculate the Einstein coefficient in spontaneous emission of, say, two-level atoms through feynman diagrams? I searched for sources in google but could not find anything. Thanks a lot for an answer! Wit best regards, blue2script

Homework Statement Show that the fractional change in frequency of a photon absorbed or emitted by an atom initially at rest is \frac{\nu - \nu_o}{\nu} = \pm \frac{h\nu}{2Mc^{2}} where M is the mass of the atom, \nu_o is the frequency of the transition uncorrected for the recoil of the atom. In...

Why don’t emission and absorption properties of an atom cancel out such that no such spectral lines are seen. If electrons in atoms are excited from level 1 to level 2 and absorb energy at some specific frequency, why don’t they then emit that same frequency when they fall back down to level1...

I am trying to find an intuitive explanation for the stimulated emission phenomenon. I know the effect: a photon with the right frequency "interacts" with an excited electron to create a copy of itself( same phase, same amplitude, same state) putting the electron to a lower energy state... But...

How many neutrino emission mechanism, that causes the cooling of star, are there in neutron star? And How, what equation, to calculate the emissivity of each mechanism? thankfully, First

Let's say we just had a normal atom in energy state E, and one of the electrons jumps down to a lower orbital E'. Of course, E - E' is positive because E' is a lower orbital than E, so the energy of the photon emitted must be positive. But what if E' were a higher orbital than E? Could the...

Based on the following excerpt, I'd appreciate any general comments/observations and then follow with a specific question. Leonard Susskind says in THE BLACK HOLE WAR, 2008, PG 347 : #: my parenthetical comment I knew physics was crazy, but that just seems "over the horizon" crazy...

I wonder is what are the legal and application area difference between "Tier","EPA" and "California" Emission Standard in U.S (I am not asking the allowable emission levels). Also, Is there any difference in on-road and off-road standads(again, I am not asking the emission levels)? Thanks...

Question regarding the emission of infrared radiation, for personal knowledge. Why do humans emit infrared radiation? Is it because it just so happens that the energy humans absorb (from sunlight)/ the energy humans produce just so happens to correlate to the frequency of infrared, as...

I keep seeing the hydrogen emission spectrum from the Balman series (when an electron falls to n=2). It's all over my textbook. Why don't I ever see the Lyman series or any other series? Is it really rare for hydrogen electrons to fall to energy levels other than n=2?

Suppose I have a two-level atom trapped in a certain area, initially in ground state. I have a light shining on it, the atom jump from ground state to the excited state and emission a photon spontaneously. Can I say this is a scattering process?

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...

Hi all, I'm doing a project that includes an hydrogen 2s->1s decay and I need the full derivation of this process, so if anyone can recommend about a book it would be great. I first thought it should be easy to find but to tell you the truth I have looked and found scratch. 10x a lot...

Homework Statement Hi, I need to know the correct SI units for Einstein Coefficients (A and B) for stimulated emission (say laser). The equation I'm on about is Homework Equations \frac{A}{B} = \frac{8\pi h\nu^{3}}{c^{3}}The Attempt at a Solution after some scribbling I got to \frac{A}{B}...

Homework Statement Part a) The emission spectrum for Sodium lamp contains a reasonably bright red line in its spectrum. What is its origin? Part b) The possible transitions between electron energy levels for Sodium were analysed. There were no transitions between the s series (s subshell)...

I was doing an undergrad experiment on the sodium emission spectrum and I have a few queries. Of course, I was asked to analyse the famous yellow doublet which I'm on top of. I was also asked the analyse the diffuse series which was fine too. What I did notice however, was a strong red line...

A hypothetical atom has five energy levels. How many emission lines will it produce?

Is it possible to find out the relative concentration of c02 by looking at the emission or absorption from a hot gas, T = 1000K, containing among other C02? What I want to find out is if the emission depends linearly on the concentration. (in the IR region) What theoretically equations may I...

What is the main physical difference behind these two theories? 1) I understand that the thermionic emission theory is applied in metal-semiconductor contacts and heterostructures where the energy band off-sets are large. Whereas the diffusion theory is applied in a simple homojunction, of...

[FONT="Times New Roman"][SIZE="3"] So I'm preparing to run an experiment involving Ionization. Unfortunately during my research, I've found out that when air is ionized (much like a lightning strike) it produces ozone. I learned that ozone molecules are unstable and usually dissipate back into...

Hey what's the relationship between the width of emission lines and the uncertainty principle? My lecturer mentioned it briefly but didn't go into it. I think I get it but would have trouble explaining it. Cheers, nSlavingBlair

k my physics background is limited , I know that photon emission is when the electron moves down in energy level thus releasing a photon but how does the photon get inside the electron , the energy that moves the electron into a higher level when this energy moves the electron out their...