electrospinning +15kV and -4kV = 19kV

jrwalliker@gmail.com wrote in
news:a3f205b8-a108-4276-b674-7d916dc28d50@googlegroups.com:

On Monday, 23 September 2019 10:26:26 UTC+1,
DecadentLinux...@decadence.org

There is a simple reason why it may be important to keep a stable
accelerating voltage. In order to get a sharp image the spot size
where the electron beam hits the target needs to be as small as
possible. It is very likely that the focus of the electron beam
will be affected by anode voltage, so if there is substantial
ripple the average spot size will increase, reducing the sharpness
of the final image.

John

I stated in a post that the target gets struck by the e-beam
"noisily" in such a case and the electrons dance around as opposed to
being a clean, straight stream.

But you got it. The same thing that makes a CRT anode supply
produce better quality screen framesm makes the x ray flux in a nice,
clean, linear manner.

That pretty much resolves it.

Ripple causes 'dancing' of the e-beam spot locale.

Maybe they should put adjustment e-field plates in the tube between
the anode and cathode to pin point the spot. But that too would
likely still not be as happy with a noisey HVDC supply than a clean
one.

 

On Sun, 22 Sep 2019 23:44:39 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Friday, September 20, 2019 at 7:40:48 AM UTC-7, DecadentLinux...@decadence.org wrote:
whit3rd <whit3rd@gmail.com> wrote in
news:4f959a17-8ccb-4d72-b53e-b05152280071@googlegroups.com:

On Thursday, September 19, 2019 at 8:10:44 AM UTC-7,
DecadentLinux...@decadence.org wrote:

X-rays are focused by Aluminum lenses.

Not in any useful way, they aren't.

That *must* be why they actually do it. Since it is so non-useful.

Getting an aluminum surface smooth enough to refract X-rays, and getting more
'focus' intensification than absorption-of-beam attenuation, are an unlikely
pair of achievements.

I'm not sure what 'they actually do', but it isn't focusing.

No, google it. There are aluminum (and other) focussing lenses for
x-rays.

 

[Winfield Hill]

jlarkin@highlandsniptechnology.com wrote...

No, google it. There are aluminum (and other)
focussing lenses for x-rays.

My father machined a set of those in 1958.


--
Thanks,
- Win

 

On 23 Sep 2019 08:13:07 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

jlarkin@highlandsniptechnology.com wrote...

No, google it. There are aluminum (and other)
focussing lenses for x-rays.

My father machined a set of those in 1958.

Yikes. That was probably before n/c machining.

 

[whit3rd]

On Monday, September 23, 2019 at 7:19:04 AM UTC-7, jla...@highlandsniptechnology.com wrote:

On Sun, 22 Sep 2019 23:44:39 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Friday, September 20, 2019 at 7:40:48 AM UTC-7, DecadentLinux...@decadence.org wrote:
whit3rd <whit3rd@gmail.com> wrote in
news:4f959a17-8ccb-4d72-b53e-b05152280071@googlegroups.com:

On Thursday, September 19, 2019 at 8:10:44 AM UTC-7,
DecadentLinux...@decadence.org wrote:

X-rays are focused by Aluminum lenses.

Not in any useful way, they aren't.

That *must* be why they actually do it. Since it is so non-useful.

Getting an aluminum surface smooth enough to refract X-rays, and getting more
'focus' intensification than absorption-of-beam attenuation, are an unlikely
pair of achievements.

I'm not sure what 'they actually do', but it isn't focusing.

No, google it. There are aluminum (and other) focussing lenses for
x-rays.

OK, I see the DESY description. They mention 'undulator' and '21 keV' which
leads me to believe they're starting with an X-ray laser. It wastes most of the power,
so beryllium is used (higher melting point than aluminum).
One purpose is to use the collimated laser light to make (weakly) a small point
source for microscopy. Not really an image-making focus, just a small dot
from the low-divergence broader source beam.

For those of us that don't have an X-ray laser, it's unlikely to be useful.
It also seems to depend on a negative refractive index (not impossible, but
somewhat exotic).

 

whit3rd <whit3rd@gmail.com> wrote in news:fefa26d5-cccc-477c-a3bb-
26aed1492b48@googlegroups.com:

> Not really an image-making focus,

You got it backwards. The goal is not to use it as we do visible
light optics to cast images onto surfaces. The goal is to make a
pure, nearly coherent stream of x-rays to cast THROUGH objects onto a
subsequent image plane.

The physics are a bit different than those we use to capture
visible light imagery.

The manipulation in visible light optics guides reflections and
emanations off our 3D world through the optics, onto a flat or curved
image 'plane'. So from telescopes to your eyes all work the same.

The manipulation of an x-ray flux is such that when it gets casts
onto (and thus through) an object, it will contain the least randomly
scattered particles and gain the most collimation through the target
and onto the image plane. That collimation is essential to good
imagery and dose control. Scattering would raise noise floor, as it
were. One would imagine that the 'focus' under discusssion are
elements which handles the freshly emitted flux at a point prior to
the collimation elements.

You seem to have a mindset like this is some kind of flat screen
Wall projector.

Another good explaination scenario.

A visible spectrum regular TV projector casts visible light through
a subtractive color mixing image plane and then up onto a screen
across the room. The light is 'collimated' from the source, through
the image plane, and up onto your wall as a four sided pyramid.

An x-ray machine casts a more linearly collimated beam of xray flux
through a target object and onto a subsequent image plane and
captures information based on the number of those x-ray particles
that make it through the target and onto the image plane allowing one
to peer into the internal structure of the target. Any talk of
"focus" relates to gaining that 'best case' 'most accurate'
collimated beam with which to cast through that target. This is
entirely different than 'ordinary' 'optics' imagery storage where
reflections are captured from light guided through the optics onto
the plane. X-ray is through the target onto the plane.

 

On Tue, 24 Sep 2019 13:01:08 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

whit3rd <whit3rd@gmail.com> wrote in news:fefa26d5-cccc-477c-a3bb-
26aed1492b48@googlegroups.com:

Not really an image-making focus,

You got it backwards. The goal is not to use it as we do visible
light optics to cast images onto surfaces. The goal is to make a
pure, nearly coherent stream of x-rays to cast THROUGH objects onto a
subsequent image plane.

Not coherent, unless you have an xray laser.

 

[Winfield Hill]

sroberts6328@gmail.com wrote...

Search for Darrell Reneker for the publications.
The Thesis of Tao Han and Han Xu are really interesting.

I just wanted to say, Steve, how very helpful your
advice and remarks about this topic have been for us.
Thank you bigtime!


--
Thanks,
- Win

 

jlarkin@highlandsniptechnology.com wrote in
news:4c9koetgb7tld4sehuga400nq604je403r@4ax.com:

On Tue, 24 Sep 2019 13:01:08 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

whit3rd <whit3rd@gmail.com> wrote in news:fefa26d5-cccc-477c-a3bb-
26aed1492b48@googlegroups.com:

Not really an image-making focus,

You got it backwards. The goal is not to use it as we do
visible
light optics to cast images onto surfaces. The goal is to make a
pure, nearly coherent stream of x-rays to cast THROUGH objects
onto a subsequent image plane.

Not coherent, unless you have an xray laser.

Collimated, johnny. Use your brain. You know what I meant.

 

On Wed, 25 Sep 2019 08:17:34 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news:4c9koetgb7tld4sehuga400nq604je403r@4ax.com:

On Tue, 24 Sep 2019 13:01:08 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

whit3rd <whit3rd@gmail.com> wrote in news:fefa26d5-cccc-477c-a3bb-
26aed1492b48@googlegroups.com:

Not really an image-making focus,

You got it backwards. The goal is not to use it as we do
visible
light optics to cast images onto surfaces. The goal is to make a
pure, nearly coherent stream of x-rays to cast THROUGH objects
onto a subsequent image plane.

Not coherent, unless you have an xray laser.



Collimated, johnny. Use your brain. You know what I meant.

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

 

[Bill Sloman]

On Thursday, September 26, 2019 at 1:02:26 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Wed, 25 Sep 2019 08:17:34 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news:4c9koetgb7tld4sehuga400nq604je403r@4ax.com:

On Tue, 24 Sep 2019 13:01:08 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

whit3rd <whit3rd@gmail.com> wrote in news:fefa26d5-cccc-477c-a3bb-
26aed1492b48@googlegroups.com:

Not really an image-making focus,

You got it backwards. The goal is not to use it as we do
visible
light optics to cast images onto surfaces. The goal is to make a
pure, nearly coherent stream of x-rays to cast THROUGH objects
onto a subsequent image plane.

Not coherent, unless you have an xray laser.

Collimated, johnny. Use your brain. You know what I meant.

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

Correct. He didn't misapply them, but he did use them in a context with which you weren't familiar.

It's tricky to post stuff that is spelled out in enough detail that those unfamiliar with an area can still work out what's meant.

Certain audiences require heroic efforts, which DLUNU failed to exert.

There's not a lot of point in keeping the peanut gallery informed.

--
Bill Sloman, Sydney

 

jlarkin@highlandsniptechnology.com wrote in
news:i70noelsi4ie768hhph0hkh6btp96jje07@4ax.com:

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

I properly applied the term sputtering.

Coherent was the wrong term.

You are decidedly too stupid to tell the difference and far too
fucked in the head to grasp the contextual application in the first
case, which is why you got that one wrong, and far too stupid to get a
grip on the second case, because you do not follow or participate in
discussions, you perform cursory perusals and take jabs at folks. It
is really sad and blatantly obvious how poor you are at playing a know
it all.

 

On Thu, 26 Sep 2019 01:41:24 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news:i70noelsi4ie768hhph0hkh6btp96jje07@4ax.com:

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

I properly applied the term sputtering.

https://en.wikipedia.org/wiki/Sputtering

 

[Bill Sloman]

On Thursday, September 26, 2019 at 12:09:12 PM UTC+10, jla...@highlandsniptechnology.com wrote:

On Thu, 26 Sep 2019 01:41:24 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news:i70noelsi4ie768hhph0hkh6btp96jje07@4ax.com:

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

I properly applied the term sputtering.

https://en.wikipedia.org/wiki/Sputtering

"In physics, sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas."

The dictionary definition includes this meaning, but there are others.

'make a series of soft explosive or spitting sounds.
"the engine sputtered and stopped"

speak in a series of incoherent bursts as a result of strong emotion.
"‘But … but …’ she sputtered"
emit with a spitting sound.
"the goose is in the oven, sputtering fat"
proceed in a spasmodic and feeble way.
"strikes in the public services sputtered on"

2.
Physics
deposit (metal) on a surface by using fast ions to eject particles of it from a target.

coat (a surface) with a spray of metal particles emitted from a target that is bombarded with fast ions.'

John Larkin's definition of "properly" is a trifle self serving.

--
Bill Sloman, Sydney

 

jlarkin@highlandsniptechnology.com wrote in
news:ba7ooe1md6fqc39cric61sj3v589b5hnls@4ax.com:

On Thu, 26 Sep 2019 01:41:24 +0000 (UTC),
DecadentLinuxUserNumeroUno@decadence.org wrote:

jlarkin@highlandsniptechnology.com wrote in
news:i70noelsi4ie768hhph0hkh6btp96jje07@4ax.com:

That's funny. When you misapply common terms like sputtering and
coherent, it's my fault if I don't understand your intent.

I properly applied the term sputtering.


https://en.wikipedia.org/wiki/Sputtering

Sorry, oh ye of little education... you chose incorrectly, and
lack the brainpower appaerntly to grasp that the term was around long
before it was applied in metallic deposition technology.

Nice try though.

Good job of illustrating it by sputtering about in the thread,
despite it being explained to you days ago.

You must be a true idiot to have chosen a vapor deposition process
term when it is quite obvious that was not the topic of discussion
and therefore not the term association you so blatantly incorrectly
chose. And no, one should not have to lead you around by the hand.