thermionic emission from hot anode on reverse part of cycle will melt delicate cathode!

Took me a minute to realize a hot anode will act as a cathode if it's hot enough to emit electrons.

 

a cathode ray tube, used for x-ray production, in which a beam of thermoelectrons is produced by heating a wire cathode.

#12 that's right! Xray tubes and picture tubes are both descended from Crookes tube (which was both) so they are basically sisters and really the first electron tubes! I agree with HP that it's poignant that the xray tube which is the only tube that can't now be replaced with semiconductor technology is like Tolkien's Tom Bombadil!
So if and when xray tubes become obsolete it will be like quote from trilogy:

_ Bombadil will fall, Last as he was First; and then night will come_

So for parallel to tubes night is sun setting on age of electron tubes after the last holdout (which is xray tube) has fallen by the wayside

 

the x-ray tube which is the only tube that can't now be replaced with semiconductor technology

A 20th century curmudgeon said, "There's nothing you can do with a vacuum tube that you can't do with 4 or 5 transistors." but he was bemoaning the death of pentagrid converters, not, "how to make x-rays without splattering high velocity, sub-atomic particles against a stationary target". The mere concept drives my mind toward inter-stellar phenomenon, but I'm sure a thousand people have gone there before me, and with much better intellectual equipment.

 

FWIW All Brinelling I've encountered (which being principally in rotary wing aircraft mast bearings and RA Coolidge tube anode bearings) represents discrete 'indentations' in the race sans significant material loss -- Perhaps such is unique to damage/wear owed to dynamic imbalance?

Very best regards
HP

We used to see it all the time in disk drives caused by drop tests.
The drives that didn't have the heads on the disk during shipping also were prone to fretting due the small rotations in the same spot. Like @#12 says a million ways to loose your bearings.

 

Like @#12 says a million ways to loose your bearings.

My intent was about a Paul Simon song...50 ways to leave your lover.
inspired by post #978
shortbus and his link to 53 photos of agonized bearings.

 

A 20th century curmudgeon said, "There's nothing you can do with a vacuum tube that you can't do with 4 or 5 transistors." but he was bemoaning the death of pentagrid converters, not, "how to make x-rays without splattering high velocity, sub-atomic particles against a stationary target". The mere concept drives my mind toward inter-stellar phenomenon, but I'm sure a thousand people have gone there before me, and with much better intellectual equipment.

#12 theoretically it can be done by like cascaded SHG resonators but if you look at physics of getting to hard xrays from EUV I say it's total bilge cuz whole concept of inversion symmetry loses meaning when wavelength is smaller than molecules comprising crystal! So it's for sure that they'd need another way of achieving nonliterary than just NLO techniques! Anyhow I say getting to xrays by _frequency multiplication_ is blind alley for too many reasons!

#12 Just so I'm not asking you to take my word for anything here's link to PDF of introductory treatise on nonlinear optics. I read through it so I can say that even though it's very basic it does good job of introducing reader to the basic concepts and math It took me awhile to find good article for non scientist reader (which is how I think you're describing yourself?) so plz have a look and enjoy how math and logic _blows up_ if you try to apply it to EUV and XRAY wavelengths! So being fair the paper is competently written and it's not claiming to be applicable to xrays! But it gives you tools to walk through implications of different wavelengths/PEs

Also getting back to _solid state xray source_ I agree with HP that just opening and closing molecular shield over radioisotope gamma source does not qualify!

So anyhow I say _Mr. Bombadil_ has lots of good years ahead of him!

 

My intent was about a Paul Simon song...50 ways to leave your lover.
inspired by post #978
shortbus and his link to 53 photos of agonized bearings.

 

Oh, by the way...I just spent half the night on youtube learning about British slang and naughty words. You people cuss so gently that it doesn't seem worth the effort to study.

On the other hand, Nonlinear Optical Susceptibility proves that our Constitution is wrong. All (men) are not created equal. I can't even read the darn thing! The induced polarization depends linearly on the electric field strength? Since when does an electric field polarize light? And that's the second page, first sentence!

Should I try wearing my polarized sun glasses when looking at an inductor to see how it affects polarization of light?
Color me lost.

 

Oh, by the way...I just spent half the night on youtube learning about British slang and naughty words. You people cuss so gently that it doesn't seem worth the effort to study.

#12 HP mostly grew up in UK but I'm totally N. American made!

Since when does an electric field polarize light?

#12 ever hear of Kerr cells or just LCD displays? Cuz that's exactly their principal of operation

I can't even read the darn thing!

#12 I'm sry you found it condescending But being fair I warned you it's just introductory treatment.

Should I try wearing my polarized sun glasses when looking at an inductor to see how it affects polarization of light?

#12 being serious a strong electrostatic field might rotate polarization angle of LCD layer of auto adjusting shades enough to make noticeable change to opacity!

So just polarized shades won't be effected like that but they make it easy to see rotation of polarization by other materials

 

HP mostly grew up in UK but I'm totally N. American made!

Thank you. (I hope that's really your face because it is very pleasant to look at.)

#12 ever hear of Kerr cells or just LCD displays? Cuz that's exactly their principal of operation

Thank you.

#12 I'm sry you found it condescending But being fair I warned you it's just introductory treatment.

I didn't say it was condescending. I couldn't understand it because it is so far out of my experience that I can't tell whether it is pure science or a joke you might be playing on me. I have no comprehension whatsoever on that subject.

#12 being serious a strong electrostatic field might rotate polarization angle of LCD layer of auto adjusting shades enough to make noticeable change to opacity!

Thank you.

 

I didn't say it was condescending. I couldn't understand it because it is so far out of my experience that I can't tell whether it is pure science or a joke you might be playing on me. I have no comprehension whatsoever on that subject.

#12 remember how you once said you have ability to divine purview of ppl asking questions? I say that's great gift I just don't have So it just means I inherited teacher wannabe gene from HP

Anyhow tnx for giving it a look!

 

#12 standard tubes (with max anode AV ≤ 4000 RPM) are lubricated with powdered silver and high speed tubes (sometimes > 10,000 RPM)

Ah, ha, you just hit on the main cause of brinneling in a bearing, high speed. This is why in mechanics class they tell you to never 'spin' the bearing with an air hose when cleaning them. The air from the nozzle will drive the bearing past the RPM limit of the bearing. And all rolling element bearings have a maximum RPM limit, before damage takes place, usually brinneling.

 

I hope that's really your face because it is very pleasant to look at

#12 it's really just computer generated image of _average Polish woman_ from web. But how I found it was from search on pic of myself under _visually similar images_ so it's totally close enough for me to say thanks for compliment!

 

12 remember how you once said you have ability to divine purview of ppl asking questions?

Purview, noun:
1.the range of operation, authority, control, concern, etc.
2.the range of vision, insight, or understanding.

Excellent choice of words Only upon investigation did I realize how appropriate that word is in this situation.
I make a serious effort to address questioners on their level of competence and language facility, including dialect.
I think any success I may have is due to diligence.
I am familiar with having lesser talents. My nephew, ne'er do well that he is, has an ability to divine purview so well that I study him on this subject! You may claim to have no such talent, but I am only mediocre.

#12 it's really just computer generated image of _average Polish woman_ from web.

How do I appreciate that image? My first wife was Polish. (Mixed emotions about revealing that.)

 

I make a serious effort to address questioners on their level of competence and language facility, including dialect.

well that explains a lot ... thanks for the patience ...

 

#12 remember how you once said you have ability to divine purview of ppl asking questions?

I have just demonstrated a failure to divine purview. Your fake, "numptyism" contrasted with the prodigious vocabulary of HP, and the known connection between you two, confused me so much that I could not tell you are mostly American.

I will feel free to throw more American slang your way.

 

well that explains a lot ... thanks for the patience ...

I merely consider it part of the job. We deal with every level of competence here. Finding the right response is paramount to our function.

 

I have just demonstrated a failure to divine purview.

I could not tell you are mostly American.

#12 I say that's not a fail at all! Being raised by HP I prolly picked up a thing or two

So anyhow it's not just you cuz remember some ppl even thought we were _puppets_ at first

 

Being raised by HP I prolly picked up a thing or two

I feel like I am being raised by HP, too. (Not quite in the same way you used that word.)
Her level of articulation is unique on this Website. It is quite a leap for me to traverse between trying to address HP and the other 99%.

Edit: The word I was searching for was, "elevated".

 

#12 I say that's not a fail at all! Being raised by HP I prolly picked up a thing or two

Ya think?

TTFN
HP