Vladimir,
thanks for the reply, any info will be appreciated. I was under the
impression that solar filters made of coated Mylar use aluminium, but I
may be totally wrong. At least some of the coated glass filters are
marketed as containing chromium, but this is the first time I've heard of
Inconel. Thanks!

One added complication is that I'll be using a fisheye lens. This means
that any filter will have to be placed behind the lens. This in turn means
- at least in theory - that thick glass will introduce spherical
aberration, the thicker the worse. I've thought about stacking two solar
filters, but since the absorption type solar filters generally have a
really terrible tint to them and two reflective filters probably would
give a terrible blur due to light bouncing back and forth between them, my
best idea so far is to add a reflective coating to a (thin) absorption
filter.

Any ideas or comment will be appreciated. Sorry if this is perceived as
being off-topic, I hope that the list server can keep up with the extra
traffic ;o)

Regards,
Thomas

Thomas,

Al with thickness > 80 -100 nm doesn't transmit visible light. If you
will, tomorrow I can give you data for thicknesses from 0 to 80 nm.
However Al is not used for neutral density filters - it is soft and has
no uniform spectral parameters in the visible range. Usually Inconel is
used as a material for coated optical filters. However I do not think
you can realize 300000.......x with just one filter because there will
be troubles with such filter repeatability, monitoring, and testing.
Maximal optical density of coated filters is usually 5, probably, some
experts can coat more.... So you'll need a few of them or use them
together with SCHOTT neutral color glass.

Regards,

Vladimir

Thomas Bryhn wrote:

Hello,
I've been lurking here for quite some time. I haven't got the space to
build myself a vacuum system, but that certainly doesn't keep me from
dreaming. And this post really caught my eye.

Does anybody know the relationship between the thickness of deposited
aluminium and the filter factor (light reduction factor)? I've got a
photo
project that calls for a filter factor of 3000000000x (yes, that's grad
9.5), and filters like these are not exactly off-the-shelf items ...

Regards,
Thomas Bryhn

Ken,

I opened the little crystal holder yesterday to see what was in there
that
made it so expensive. Aside from them spring clips holding the crystal
holder in place it did not look all that exotic. Must be more to it
than
seems.

I wanted to test the accuracy of the crystal detector so I only put
0.600
kA ( 60 nanometer ) of aluminum on the test glass. When I took it out
and held it to the sun it looked exactly like 60 nm should. I am very
impressed with the whole electronic detection thing. Very impressed
indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I
put
down 1 nm in 10 minutes of deposition. Not such a good idea to go so
slowly. I had a grounding issue in the chamber so the baffle box was
only
getting 5% of its needed amperage. The coating was very smooth but it
was
butter soft. But aside from that total failure to bond on a hard
coating
, the XMS-1 controller worked perfectly. It staged thru the power
levels and indicated rate of deposition and total deposition correctly.
Nothing burned up so I think further testing this week is a strong
possibility. I fixed the grounding / current flow issued and now have
1000 amps at 1.7 vac available.

Drew in soggy FLA

------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

Ken,

Yes I did use the ramp control. 2 minutes of 30% then 2 minutes of 60% then 90% till 1.37 kA were achieved. But my grounding problem prevented me from getting any real power to the baffle box. After I discovered the problem I put a few inches of kiln heater coil across the power supply and ramped the power back up. At 30% it melted the kiln coil in seconds. The digital switch seems to be working fine. I am getting controlled 230 vac out of the digital switch at a few amps and it is being transformed down to 2 vac at hundreds of amps.

Hey, do you have another one of them things ??? I want to install a second one so I can run two of them heater baffle boxes at the same time. I got two of them monster transformers in my welder box that I am using as the power supply.

I stripped the mirror down last night and found some very interesting stuff. There was nothing wrong with my surface polish. The baffle box was spitting. They are not supposed to but this one does. It may be from me putting it on its side or it may have been from the way too low amperage but it sputtered. The mess I saw on the mirror was like fine oil droplets that had been discharged from a distance.

I am thinking that I will have to create a blocker of some kind to catch the initial sputtering from the baffle box as it heats up. You got any idea on that ???? The controller will actuate it on command so control is not a problem.

Drew


From: VacuumX@... [mailto:VacuumX@...] On Behalf Of Ken
Sent: Monday, August 23, 2010 2:31 PM
To: VacuumX@...
Subject: [VacuumX] Re: Wanted - Deposition Crystal holder



Drew...

Expensive those little springs...

Did you use the electronic controller to ramp up and down the current? I used it to control a lamp but not an evap system myself. Wondering how that worked out and was my instructions adequate?

Congrats on getting where I could not go!

Ken

--- In VacuumX@...<mailto:VacuumX%40yahoogroups.com>, "Aurigema, Andrew N. (KSC-ASRC-474)[ASRC AEROSPACE]" <andrew.n.aurigema@> wrote:

Ken,

I opened the little crystal holder yesterday to see what was in there that made it so expensive. Aside from them spring clips holding the crystal holder in place it did not look all that exotic. Must be more to it than seems.

I wanted to test the accuracy of the crystal detector so I only put 0.600 kA ( 60 nanometer ) of aluminum on the test glass. When I took it out and held it to the sun it looked exactly like 60 nm should. I am very impressed with the whole electronic detection thing. Very impressed indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I put down 1 nm in 10 minutes of deposition. Not such a good idea to go so slowly. I had a grounding issue in the chamber so the baffle box was only getting 5% of its needed amperage. The coating was very smooth but it was butter soft. But aside from that total failure to bond on a hard coating , the XMS-1 controller worked perfectly. It staged thru the power levels and indicated rate of deposition and total deposition correctly. Nothing burned up so I think further testing this week is a strong possibility. I fixed the grounding / current flow issued and now have 1000 amps at 1.7 vac available.

Drew in soggy FLA

From: VacuumX@...<mailto:VacuumX%40yahoogroups.com> [mailto:VacuumX@...<mailto:VacuumX%40yahoogroups.com>] On Behalf Of Ken
Sent: Friday, August 20, 2010 5:37 PM
To: VacuumX@...<mailto:VacuumX%40yahoogroups.com>
Subject: [VacuumX] Re: Wanted - Deposition Crystal holder



I bough them on eBay...

Ken

--- In VacuumX@...<mailto:VacuumX%40yahoogroups.com><mailto:VacuumX%40yahoogroups.com>, "arainho_cl" <aneves@> wrote:

Hi Ken,

Who do you buy the crystals from?

Regards,

Alfredo

Vladimir,
thanks for the reply, any info will be appreciated. I was under the
impression that solar filters made of coated Mylar use aluminium, but I
may be totally wrong. At least some of the coated glass filters are
marketed as containing chromium, but this is the first time I've heard of
Inconel. Thanks!

One added complication is that I'll be using a fisheye lens. This means
that any filter will have to be placed behind the lens. This in turn means
- at least in theory - that thick glass will introduce spherical
aberration, the thicker the worse. I've thought about stacking two solar
filters, but since the absorption type solar filters generally have a
really terrible tint to them and two reflective filters probably would
give a terrible blur due to light bouncing back and forth between them, my
best idea so far is to add a reflective coating to a (thin) absorption
filter.

Any ideas or comment will be appreciated. Sorry if this is perceived as
being off-topic, I hope that the list server can keep up with the extra
traffic ;o)

Regards,
Thomas

Thomas,

Al with thickness > 80 -100 nm doesn't transmit visible light. If you
will, tomorrow I can give you data for thicknesses from 0 to 80 nm.
However Al is not used for neutral density filters - it is soft and has
no uniform spectral parameters in the visible range. Usually Inconel is
used as a material for coated optical filters. However I do not think
you can realize 300000.......x with just one filter because there will
be troubles with such filter repeatability, monitoring, and testing.
Maximal optical density of coated filters is usually 5, probably, some
experts can coat more.... So you'll need a few of them or use them
together with SCHOTT neutral color glass.

Regards,

Vladimir

Thomas Bryhn wrote:

Hello,
I've been lurking here for quite some time. I haven't got the space to
build myself a vacuum system, but that certainly doesn't keep me from
dreaming. And this post really caught my eye.

Does anybody know the relationship between the thickness of deposited
aluminium and the filter factor (light reduction factor)? I've got a
photo
project that calls for a filter factor of 3000000000x (yes, that's grad
9.5), and filters like these are not exactly off-the-shelf items ...

Regards,
Thomas Bryhn

Ken,

I opened the little crystal holder yesterday to see what was in there
that
made it so expensive. Aside from them spring clips holding the crystal
holder in place it did not look all that exotic. Must be more to it
than
seems.

I wanted to test the accuracy of the crystal detector so I only put
0.600
kA ( 60 nanometer ) of aluminum on the test glass. When I took it out
and held it to the sun it looked exactly like 60 nm should. I am very
impressed with the whole electronic detection thing. Very impressed
indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I
put
down 1 nm in 10 minutes of deposition. Not such a good idea to go so
slowly. I had a grounding issue in the chamber so the baffle box was
only
getting 5% of its needed amperage. The coating was very smooth but it
was
butter soft. But aside from that total failure to bond on a hard
coating
, the XMS-1 controller worked perfectly. It staged thru the power
levels and indicated rate of deposition and total deposition correctly.
Nothing burned up so I think further testing this week is a strong
possibility. I fixed the grounding / current flow issued and now have
1000 amps at 1.7 vac available.

Drew in soggy FLA

------------------------------------

Yahoo! Groups Links

Dear Alfredo

I will interested in the patent you mentioned. Kindly send me the reference


zafar

To: VacuumX@...
From: aneves@...
Date: Tue, 24 Aug 2010 01:45:00 +0000
Subject: [VacuumX] E-Gun Evaporator




























Hi All,



I've been interrested in learning about E-Gun evaporators and have added a link to a patent that describes such an E-Gun for those interrested.



Regards,



Alfredo

Thomas,

Al with thickness > 80 -100 nm doesn't transmit visible light. If you
will, tomorrow I can give you data for thicknesses from 0 to 80 nm.
However Al is not used for neutral density filters - it is soft and has
no uniform spectral parameters in the visible range. Usually Inconel is
used as a material for coated optical filters. However I do not think
you can realize 300000.......x with just one filter because there will
be troubles with such filter repeatability, monitoring, and testing.
Maximal optical density of coated filters is usually 5, probably, some
experts can coat more.... So you'll need a few of them or use them
together with SCHOTT neutral color glass.

Regards,

Vladimir

Thomas Bryhn wrote:

Hello,
I've been lurking here for quite some time. I haven't got the space to
build myself a vacuum system, but that certainly doesn't keep me from
dreaming. And this post really caught my eye.

Does anybody know the relationship between the thickness of deposited
aluminium and the filter factor (light reduction factor)? I've got a
photo
project that calls for a filter factor of 3000000000x (yes, that's grad
9.5), and filters like these are not exactly off-the-shelf items ...

Regards,
Thomas Bryhn

Ken,

I opened the little crystal holder yesterday to see what was in there
that
made it so expensive. Aside from them spring clips holding the crystal
holder in place it did not look all that exotic. Must be more to it
than
seems.

I wanted to test the accuracy of the crystal detector so I only put
0.600
kA ( 60 nanometer ) of aluminum on the test glass. When I took it out
and held it to the sun it looked exactly like 60 nm should. I am very
impressed with the whole electronic detection thing. Very impressed
indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I
put
down 1 nm in 10 minutes of deposition. Not such a good idea to go so
slowly. I had a grounding issue in the chamber so the baffle box was
only
getting 5% of its needed amperage. The coating was very smooth but it
was
butter soft. But aside from that total failure to bond on a hard
coating
, the XMS-1 controller worked perfectly. It staged thru the power
levels and indicated rate of deposition and total deposition correctly.
Nothing burned up so I think further testing this week is a strong
possibility. I fixed the grounding / current flow issued and now have
1000 amps at 1.7 vac available.

Drew in soggy FLA

------------------------------------

Yahoo! Groups Links

Hello,
I've been lurking here for quite some time. I haven't got the space to
build myself a vacuum system, but that certainly doesn't keep me from
dreaming. And this post really caught my eye.

Does anybody know the relationship between the thickness of deposited
aluminium and the filter factor (light reduction factor)? I've got a photo
project that calls for a filter factor of 3000000000x (yes, that's grad
9.5), and filters like these are not exactly off-the-shelf items ...

Regards,
Thomas Bryhn

Ken,

I opened the little crystal holder yesterday to see what was in there that
made it so expensive. Aside from them spring clips holding the crystal
holder in place it did not look all that exotic. Must be more to it than
seems.

I wanted to test the accuracy of the crystal detector so I only put 0.600
kA ( 60 nanometer ) of aluminum on the test glass. When I took it out
and held it to the sun it looked exactly like 60 nm should. I am very
impressed with the whole electronic detection thing. Very impressed
indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I put
down 1 nm in 10 minutes of deposition. Not such a good idea to go so
slowly. I had a grounding issue in the chamber so the baffle box was only
getting 5% of its needed amperage. The coating was very smooth but it was
butter soft. But aside from that total failure to bond on a hard coating
, the XMS-1 controller worked perfectly. It staged thru the power
levels and indicated rate of deposition and total deposition correctly.
Nothing burned up so I think further testing this week is a strong
possibility. I fixed the grounding / current flow issued and now have
1000 amps at 1.7 vac available.

Drew in soggy FLA

------------------------------------

Yahoo! Groups Links

Ken,

I opened the little crystal holder yesterday to see what was in there that
made it so expensive. Aside from them spring clips holding the crystal
holder in place it did not look all that exotic. Must be more to it than
seems.

I wanted to test the accuracy of the crystal detector so I only put 0.600
kA ( 60 nanometer ) of aluminum on the test glass. When I took it out
and held it to the sun it looked exactly like 60 nm should. I am very
impressed with the whole electronic detection thing. Very impressed
indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I put
down 1 nm in 10 minutes of deposition. Not such a good idea to go so
slowly. I had a grounding issue in the chamber so the baffle box was only
getting 5% of its needed amperage. The coating was very smooth but it was
butter soft. But aside from that total failure to bond on a hard coating
, the XMS-1 controller worked perfectly. It staged thru the power
levels and indicated rate of deposition and total deposition correctly.
Nothing burned up so I think further testing this week is a strong
possibility. I fixed the grounding / current flow issued and now have
1000 amps at 1.7 vac available.

Drew in soggy FLA

Hi Alfredo,
If you can get your hands on "Rourke's(or Roark,s) Formulas for Stress and Strain", under formulas for elastic stability of plates and shells, you should find a formula for thin tubes under uniform external pressure, lateral and longitudinal, (Chapt. 14, table 35, #20, in the fifth edition). It's not an easy formula to use, but it might be a starting place. As Peter says, it's a complicated subject.

Ted



--- In VacuumX@..., "arainho_cl" <aneves@> wrote:

Hi Attila,

I've been looking all over for such a formula! Thanks.

Hi Attila,

I've been looking all over for such a formula! Thanks.

Ken,

I opened the little crystal holder yesterday to see what was in there that made it so expensive. Aside from them spring clips holding the crystal holder in place it did not look all that exotic. Must be more to it than seems.

I wanted to test the accuracy of the crystal detector so I only put 0.600 kA ( 60 nanometer ) of aluminum on the test glass. When I took it out and held it to the sun it looked exactly like 60 nm should. I am very impressed with the whole electronic detection thing. Very impressed indeed ( for 1970's tech ).

I actually laid down my first nanometer of SiO yesterday. Literally I put down 1 nm in 10 minutes of deposition. Not such a good idea to go so slowly. I had a grounding issue in the chamber so the baffle box was only getting 5% of its needed amperage. The coating was very smooth but it was butter soft. But aside from that total failure to bond on a hard coating , the XMS-1 controller worked perfectly. It staged thru the power levels and indicated rate of deposition and total deposition correctly. Nothing burned up so I think further testing this week is a strong possibility. I fixed the grounding / current flow issued and now have 1000 amps at 1.7 vac available.

Drew in soggy FLA

From: VacuumX@... [mailto:VacuumX@...] On Behalf Of Ken
Sent: Friday, August 20, 2010 5:37 PM
To: VacuumX@...
Subject: [VacuumX] Re: Wanted - Deposition Crystal holder



I bough them on eBay...

Ken

--- In VacuumX@...<mailto:VacuumX%40yahoogroups.com>, "arainho_cl" <aneves@> wrote:

Hi Ken,

Who do you buy the crystals from?

Regards,

Alfredo

Hi Attila,

I've been looking all over for such a formula! Thanks.

So if I use:

t = 0.125"
d = 16"

I get 50 pounds/inch

Which means that if I have a bell shaped stainless steel chamber with 1/8" wall thickness I have a safety factor of 3.3! I am no structural engineer but may be I should have a thicker wall so I have more margin, what is your thoughts?

Could you give us a reference for this formula, I think it's a very important formula for this group to have. What about using other materials like aluminium.

Regards,

Alfredo

--- In VacuumX@..., "Attila" <schneyolo@> wrote:

Hi

There is an equation

P=1000(1-square root(1-1600(t^2/d^2)))

P outer pressure pound/inch
t wall thickness
d outer diameter of the chamber measured in inch

I hope this helps, for me worked!

Attila
The Hun
www.ebeamguns.com


--- In VacuumX@..., "arainho_cl" <aneves@> wrote:

Hi,

I just got an 16" x 1" thick 1020 steel disc (SS was too expensive) for my new base plate. I turned it flat and to prevent rusting I would like to have it chromed. Is there any objections to chroming the base plate. Is chrome or niquel better?

I now want to make a Stainless Steel chamber and have been wondering what is the minimum thickness I can use for an 14" bell shaped chamber.

Regards and thanks for all the advices,

Alfredo

Hi Attila,

I've been looking all over for such a formula! Thanks.

So if I use:

t = 0.125"
d = 16"

I get 50 pounds/inch

Which means that if I have a bell shaped stainless steel chamber with 1/8" wall thickness I have a safety factor of 3.3! I am no structural engineer but may be I should have a thicker wall so I have more margin, what is your thoughts?

Could you give us a reference for this formula, I think it's a very important formula for this group to have. What about using other materials like aluminium.

Regards,

Alfredo

--- In VacuumX@..., "Attila" <schneyolo@...> wrote:

Hi

There is an equation
P=1000(1-square root(1-1600(t^2/d^2)))

P outer pressure pound/inch
t wall thickness
d outer diameter of the chamber measured in inch

I hope this helps, for me worked!

Attila
The Hun
www.ebeamguns.com


--- In VacuumX@..., "arainho_cl" <aneves@> wrote:

Hi,

I just got an 16" x 1" thick 1020 steel disc (SS was too expensive) for my new base plate. I turned it flat and to prevent rusting I would like to have it chromed. Is there any objections to chroming the base plate. Is chrome or niquel better?

I now want to make a Stainless Steel chamber and have been wondering what is the minimum thickness I can use for an 14" bell shaped chamber.

Regards and thanks for all the advices,

Alfredo

------------------------------------

Yahoo! Groups Links

Hi

There is an equation

P=1000(1-square root(1-1600(t^2/d^2)))

P outer pressure pound/inch
t wall thickness
d outer diameter of the chamber measured in inch

I hope this helps, for me worked!

Attila
The Hun
www.ebeamguns.com


--- In VacuumX@..., "arainho_cl" <aneves@> wrote:

Hi,

I just got an 16" x 1" thick 1020 steel disc (SS was too expensive) for my new base plate. I turned it flat and to prevent rusting I would like to have it chromed. Is there any objections to chroming the base plate. Is chrome or niquel better?

I now want to make a Stainless Steel chamber and have been wondering what is the minimum thickness I can use for an 14" bell shaped chamber.

Regards and thanks for all the advices,

Alfredo