Uncovering the Initial Conditions of Electrons in the Ives-Stillwell Experiment

  • Context: Graduate 
  • Thread starter Thread starter exmarine
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the initial conditions of electrons in the Ives-Stillwell experiment, exploring how these conditions may influence the emitted photons and the overall results of the experiment. The scope includes theoretical considerations and interpretations of experimental setups.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the assumption that only the positive ions' state of motion affects the emitted photons, suggesting that both positive and negative charges contribute to the photon emission.
  • There is speculation about whether the initial conditions of the electrons could be considered "random," implying that the net directed activity might primarily be due to the positive ions.
  • Another participant seeks access to the original paper by Ives and Stillwell, suggesting it may contain relevant information regarding the initial conditions of the electrons.
  • A later reply indicates that the spectral line studied was the H-Beta blue-green, noting that the initial conditions of the electrons were closely aligned with those of the nucleus, to a high degree of approximation.
  • It is mentioned that modifications to the "canal ray" tube were necessary to obtain discrete spectral lines, with a hypothesis that lowering gas pressure was a key factor in achieving this.

Areas of Agreement / Disagreement

Participants express differing views on the role of electrons and ions in the experiment, with no consensus reached regarding the implications of the initial conditions of the electrons.

Contextual Notes

There are unresolved aspects regarding the specific modifications made to the experimental setup and the exact nature of the initial conditions of the electrons.

exmarine
Messages
241
Reaction score
11
I've never been able to find the answer to this question - maybe someone on here knows the answer. What were the initial conditions of the ELECTRONS in the experiment?

There seems to be the implicit assumption that only the positive ions' state of motion has an effect on the photons being emitted. I recognize that the ions are orders of magnitude more massive than the electrons, and thus their trajectories would be essentially unaffected. But aren't the photons emitted by the JOINT actions of both positive and negative charges? And how did the electrons get past the accelerating grid into the recombination chamber?

Could the answer be that the initial conditions of the electrons are "random". And thus the "net" directed activity be that of the positive ions?
 
Physics news on Phys.org
Ok.

Does anyone know how I can find a copy of their original paper? There might be some clues in it.
 
The wikipedia provides references (and links) to two different papers by Ives and Stillwell.
 
I finally got a copy of the original paper. And the answer is that the spectral line they studied was the H-Beta blue-green(?), which is an INTERNAL transition. So the initial conditions of the electrons were the same as that of the nucleus to a very high degree of approximation.

Also, they had to significantly modify their "canal ray" tube to get discrete spectral lines. They didn't say specifically how, but I am guessing it was drastically lowering the gas pressure - to stop the impacts, mixing, random velocities and Doppler shifts that would smear the lines.
 

Similar threads

  • · Replies 46 ·
2
Replies
46
Views
6K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
8
Views
6K
  • · Replies 45 ·
2
Replies
45
Views
13K
  • · Replies 19 ·
Replies
19
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 24 ·
Replies
24
Views
24K
  • · Replies 5 ·
Replies
5
Views
4K