Wonderful work Dr. Crothers. I was wondering if you can help me with my understanding. I have developed an understanding based on Pierre- Maries works that is something like this:
The biggest thing I learned from Pierre-Marie's work, which set me off investigating this, is that emission spectra moves from lines to continuum to blackbody depending on the density of the matter.
Put another way - only solid matter has a blackbody spectrum.
Even liquid does not have a BB spectrum because there is macroscopic movement of molecules.. Its emission spectrum changes with nadir angle.
I have observed sonoluminesence spectrum going from line emission to blackbody depending on driving pressure in world record high pressure resonators.
Here is a review of our work.
Transient cavitation in high-quality-factor resonators at high static pressures.
1. J Acoust Soc Am. 2010 Jun;127(6):3456-65. doi: 10.1121/1.3377062.
http://www.ncbi.nlm.nih.gov/pubmed/20550245
I have had several conversations on high pressure arc spectra in the range several hundred torr(mm) to atmosphere with Dr. Ott at NIST. His main focus was continuum spectra. And he indicated that as pressure grew the spectrum became a continuum.
And as I researched this I began to understand that only solid matter has a blackbody, I dont think you get a blackbody spectrum just from distance through a plasma or gas...
Is this a valid understanding?
Brant
The biggest thing I learned from Pierre-Marie's work, which set me off investigating this, is that emission spectra moves from lines to continuum to blackbody depending on the density of the matter.
Put another way - only solid matter has a blackbody spectrum.
Even liquid does not have a BB spectrum because there is macroscopic movement of molecules.. Its emission spectrum changes with nadir angle.
I have observed sonoluminesence spectrum going from line emission to blackbody depending on driving pressure in world record high pressure resonators.
Here is a review of our work.
Transient cavitation in high-quality-factor resonators at high static pressures.
1. J Acoust Soc Am. 2010 Jun;127(6):3456-65. doi: 10.1121/1.3377062.
http://www.ncbi.nlm.nih.gov/pubmed/20550245
I have had several conversations on high pressure arc spectra in the range several hundred torr(mm) to atmosphere with Dr. Ott at NIST. His main focus was continuum spectra. And he indicated that as pressure grew the spectrum became a continuum.
And as I researched this I began to understand that only solid matter has a blackbody, I dont think you get a blackbody spectrum just from distance through a plasma or gas...
Is this a valid understanding?
Brant
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