Cathode rays (electron beam or e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to electrons emitted from the cathode (the electrode connected to the negative terminal of the voltage supply). They were first observed in 1869 by German physicist Julius Plücker and Johann Wilhelm Hittorf, and were named in 1876 by Eugen Goldstein Kathodenstrahlen, or cathode rays. In 1897, British physicist J. J. Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, which was later named the electron. Cathode-ray tubes (CRTs) use a focused beam of electrons deflected by electric or magnetic fields to render an image on a screen.
Here's the basic setup: A cathode ray tube is producing an electron beam which leads into a chamber. Would it be possible to put some sort of lens at the entrance of the chamber, so as to diffuse the electrons throughout said chamber.
Just to be clear, my main question is about the lens...
Homework Statement
In a TV set, an electron beam moves with horizontal velocity of 2.5 x 107 across the cathode ray tube and strikes the screen, 40 cm away.
The acceleration of gravity is 9.8 m/s2.
How far does the electron beam fall while traversing this distance? Answer in units of...
Homework Statement
An electron beam travels from an electrode on the right to one on the left. Which end of the electron beam is at a higher potential?
Homework Equations
The Attempt at a Solution
My reasoning was that if the electron beam is moving from right to left, then the...
Homework Statement
The current in the electron beam of a computer monitor is 410 µA. How many electrons per second hit the screen?
Homework Equations
The Attempt at a Solution
A beam current of 410µA means that 410µC of charge strike the screen per second. This is equivalent to...
I'm just looking at some Quantum and Atomic Physics exam papers, and I've come across a question I can't do. It's probably simple but I'm just not seeing it.
Estimate the minimum momentum necessary for a beam of electrons to probe any
possible structure within a molecule whose dimension is...
Homework Statement
The original direction of the electron beam as it enters the magnetic field is along the earth’s magnetic field. If the magnitude of the earth’s magnetic field is 0.1 mT and the magnetic field due to the Helmholtz coils is 1.0 mT (perpendicular to the electron beam), the...
Problem
An electron beam is sent through a potential barrier 4.5 \AA long. The transmission coefficient exhibits a third maximum at E = 100 \text{eV}. What is the height of the barrier?
Solution
Answer: 95.8219 \text{eV}
We know that the transmission coefficient reaches a maximum of 1 only...
The problem asks me to determine the rate of breakdown due to firing 120 kev Electrons at Titanium of arbitrary thickness. I could solve this problem if I knew The average energy deposited per electron, or the Energy efficiency of the entire beam through the titanium.
Given:
Electron Flux...
This is my first post here so hello to anybody who reads this!
I just finished calculus based physics II this semester and there are a few things I want to design and make for myself to help better my understanding of what I learned in physics. One is device I have seen that generates an...
Homework Statement
Electrons which have been accelerated from rest through a potential of 500 V pass between two parallel plates that are 6.0 cm long and 2.0 cm apart, with a potential of 150 V between them. The screen is 20 cm beyond the end of the charged plates. What is the size of the...
What is the average distance between electrons in an electron beam such as produced in a cathode ray tube as they pass through the slit and then as they pass through the charged horizontal plates and magnetic coils etc that produce the deflection?
I have a few problems that I'm not sure how to do (not sure what equations to use), can anyone help me?
1) At a certain location, the horizontal component of the Earth's magnetic field is 2.3 x 10^-5 T, due north. A proton moves eastward with just the right speed, so the magnetic force on it...