RE: [Vo]:Solar cell lifetime in space

2022-12-22 Thread Arnaud Kodeck
After drying the colloidal silica like the Ludox  
<https://www.sigmaaldrich.com/BE/en/product/aldrich/420832> 
https://www.sigmaaldrich.com/BE/en/product/aldrich/420832 is also very highly 
transparent.

 

Your coating if like fused silica is a good candidate to make a diffusion 
barrier of H2. At high temperature(above 800°C)  SS and metals diffuse H2 like 
a sponge. A layer of your product might stop the diffusion (damper it at least) 
if it is well crystalized and resist multiple heatings and coolings without 
deterioration due to thermal expansion difference between metals (or SS) and 
the SiO2 layer.

 

Some powders at high temperature are showing more and more interesting results 
for LENR. The leakage of H2 trough the vessel walls in such experiments is 
still a problem without a satisfactory solution. This may worth a try. Could it 
be easily applied on an inner surface of a pipe to have a layer like 
100~1000µm? What will be the behaviour with heating/cooling cycles over time.

 

 

From: MSF  
Sent: 22 December 2022 02:23
To: vortex-l@eskimo.com
Subject: RE: [Vo]:Solar cell lifetime in space

 

I'm not sure of the actual crystalline structure, but it's not like silica gel, 
which displays substantial optical diffusion. Given the fact that it's highly 
transparent to the point of invisibility,  I'm making the assumption that the 
structure is similar to fused quartz.

 

--- Original Message ---
On Wednesday, December 21st, 2022 at 8:32 AM, Arnaud Kodeck 
mailto:arnaud.kod...@lakoco.be> > wrote:




What is the crystal structure of the adhered layer ? Amorphous (sort of silica 
gel) or crystallized (crystalline quartz) ?

 

From: MSF mailto:foster...@protonmail.com> > 
Sent: 21 December 2022 00:00
To: vortex-l@eskimo.com <mailto:vortex-l@eskimo.com> 
Subject: Re: [Vo]:Solar cell lifetime in space

 

 

I was working with this method of surface treatment of glass more decades ago 
than I care to remember. You simply  immerse ordinary glass into a bath of 
molten potassium nitrate and the sodium Ions at the surface are replaced with 
potassium ions, resulting in a highly impact resistant glass. These days it's 
called gorilla glass, but I was using this technique long before Corning.

 

I see that  cerium doped sheet is just glass, not fused silica. So it may be 
that no cerium ions could be implanted into pure silica by the molten salt 
technique.

 

I recently discovered a method of depositing a layer of silica on any given 
surface using a ridiculously simple and inexpensive technique. This is 
something that should have been discovered 200 or so years ago, but wasn't. 
I've searched for months trying to find out if this was done before, but I find 
no reference to it. The silica layer deposited is only a few tens of microns 
thick, but the process can be repeated. Other compounds can be included; so far 
I've only tried copper. This is a solid transparent well adhered layer, not 
some powdered composite.  I really don't know what to do with this, probably 
nothing. Thought you might be interested anyway.

 

--- Original Message ---
On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg 
mailto:mules...@gmail.com> > wrote:



Foster,

You have raised an interesting possibility. I have been out of the loop for 25 
years, so my info may be dated. However, the cerium was included in the melt, 
with the quantity a djusted for the optimum UV absorption for the coverslide 
thickness. 

 

Use of a doped layer rather than the bulk could possibly provide some improved 
optical matching in the "STACK". It would have to be tested for stability 
during the thermal cycles. If the surface doping (by dipping or by ion 
implantation) is a reliable process, this might be worth mentioning it to the 
appropriate people (who I no longer know).

 

Andrew

 

-- Forwarded message -

 

I guess this is getting off into the weeds a bit, but is the quartz layer doped 
with cerium in the mass? Or is the cerium diffused into the surface by 
immersion in a molten cerium compound?

 

--

On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
mailto:mules...@gmail.com> > wrote:



 

> 

 

 

 

 



RE: [Vo]:Solar cell lifetime in space

2022-12-21 Thread MSF
I'm not sure of the actual crystalline structure, but it's not like silica gel, 
which displays substantial optical diffusion. Given the fact that it's highly 
transparent to the point of invisibility, I'm making the assumption that the 
structure is similar to fused quartz.

--- Original Message ---
On Wednesday, December 21st, 2022 at 8:32 AM, Arnaud Kodeck 
 wrote:

> What is the crystal structure of the adhered layer ? Amorphous (sort of 
> silica gel) or crystallized (crystalline quartz) ?
>
> From: MSF 
> Sent: 21 December 2022 00:00
> To: vortex-l@eskimo.com
> Subject: Re: [Vo]:Solar cell lifetime in space
>
> I was working with this method of surface treatment of glass more decades ago 
> than I care to remember. You simply immerse ordinary glass into a bath of 
> molten potassium nitrate and the sodium Ions at the surface are replaced with 
> potassium ions, resulting in a highly impact resistant glass. These days it's 
> called gorilla glass, but I was using this technique long before Corning.
>
> I see that cerium doped sheet is just glass, not fused silica. So it may be 
> that no cerium ions could be implanted into pure silica by the molten salt 
> technique.
>
> I recently discovered a method of depositing a layer of silica on any given 
> surface using a ridiculously simple and inexpensive technique. This is 
> something that should have been discovered 200 or so years ago, but wasn't. 
> I've searched for months trying to find out if this was done before, but I 
> find no reference to it. The silica layer deposited is only a few tens of 
> microns thick, but the process can be repeated. Other compounds can be 
> included; so far I've only tried copper. This is a solid transparent well 
> adhered layer, not some powdered composite. I really don't know what to do 
> with this, probably nothing. Thought you might be interested anyway.
>
> --- Original Message ---
> On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg 
>  wrote:
>
>> Foster,
>>
>> You have raised an interesting possibility. I have been out of the loop for 
>> 25 years, so my info may be dated. However, the cerium was included in the 
>> melt, with the quantity a djusted for the optimum UV absorption for the 
>> coverslide thickness.
>>
>> Use of a doped layer rather than the bulk could possibly provide some 
>> improved optical matching in the "STACK". It would have to be tested for 
>> stability during the thermal cycles. If the surface doping (by dipping or by 
>> ion implantation) is a reliable process, this might be worth mentioning it 
>> to the appropriate people (who I no longer know).
>>
>> Andrew
>>
>> -- Forwarded message -
>>
>> I guess this is getting off into the weeds a bit, but is the quartz layer 
>> doped with cerium in the mass? Or is the cerium diffused into the surface by 
>> immersion in a molten cerium compound?
>>
>> --
>>
>> On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
>>  wrote:
>>
>>>>>

RE: [Vo]:Solar cell lifetime in space

2022-12-21 Thread Arnaud Kodeck
What is the crystal structure of the adhered layer ? Amorphous (sort of silica 
gel) or crystallized (crystalline quartz) ?

 

From: MSF  
Sent: 21 December 2022 00:00
To: vortex-l@eskimo.com
Subject: Re: [Vo]:Solar cell lifetime in space

 

 

I was working with this method of surface treatment of glass more decades ago 
than I care to remember. You simply  immerse ordinary glass into a bath of 
molten potassium nitrate and the sodium Ions at the surface are replaced with 
potassium ions, resulting in a highly impact resistant glass. These days it's 
called gorilla glass, but I was using this technique long before Corning.

 

I see that  cerium doped sheet is just glass, not fused silica. So it may be 
that no cerium ions could be implanted into pure silica by the molten salt 
technique.

 

I recently discovered a method of depositing a layer of silica on any given 
surface using a ridiculously simple and inexpensive technique. This is 
something that should have been discovered 200 or so years ago, but wasn't. 
I've searched for months trying to find out if this was done before, but I find 
no reference to it. The silica layer deposited is only a few tens of microns 
thick, but the process can be repeated. Other compounds can be included; so far 
I've only tried copper. This is a solid transparent well adhered layer, not 
some powdered composite.  I really don't know what to do with this, probably 
nothing. Thought you might be interested anyway.

 

--- Original Message ---
On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg 
mailto:mules...@gmail.com> > wrote:




Foster,

You have raised an interesting possibility. I have been out of the loop for 25 
years, so my info may be dated. However, the cerium was included in the melt, 
with the quantity a djusted for the optimum UV absorption for the coverslide 
thickness. 

 

Use of a doped layer rather than the bulk could possibly provide some improved 
optical matching in the "STACK". It would have to be tested for stability 
during the thermal cycles. If the surface doping (by dipping or by ion 
implantation) is a reliable process, this might be worth mentioning it to the 
appropriate people (who I no longer know).

 

Andrew

 

-- Forwarded message -

 

I guess this is getting off into the weeds a bit, but is the quartz layer doped 
with cerium in the mass? Or is the cerium diffused into the surface by 
immersion in a molten cerium compound?

 

--

On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
mailto:mules...@gmail.com> > wrote:




 

> 

 

 

 



Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread MSF
Interesting... But I can't believe it took so long to get around to what should 
have been obvious.

--- Original Message ---
On Wednesday, December 21st, 2022 at 12:07 AM, Andrew Meulenberg 
 wrote:

> Things have gone beyond simple UV protection. At a quick glance, I found this 
> from 2014:
> "Ion exchange doping of solar cell coverglass for sunlight down-shifting"
> https://scholar.google.com/scholar_url?url=https://www.academia.edu/download/39434467/Ion_exchange_doping_of_solar_cell_coverg20151026-13237-11ddof9.pdf=en=X=jkyiY7KwAY6yyATvqZyoBQ=AAGBfm2yTEGoICv5hlwEB0RulQA-SecuDg=scholarr
>
> On Tue, Dec 20, 2022 at 4:59 PM MSF  wrote:
>
>> I was working with this method of surface treatment of glass more decades 
>> ago than I care to remember. You simply immerse ordinary glass into a bath 
>> of molten potassium nitrate and the sodium Ions at the surface are replaced 
>> with potassium ions, resulting in a highly impact resistant glass. These 
>> days it's called gorilla glass, but I was using this technique long before 
>> Corning.
>>
>> I see that cerium doped sheet is just glass, not fused silica. So it may be 
>> that no cerium ions could be implanted into pure silica by the molten salt 
>> technique.
>>
>> I recently discovered a method of depositing a layer of silica on any given 
>> surface using a ridiculously simple and inexpensive technique. This is 
>> something that should have been discovered 200 or so years ago, but wasn't. 
>> I've searched for months trying to find out if this was done before, but I 
>> find no reference to it. The silica layer deposited is only a few tens of 
>> microns thick, but the process can be repeated. Other compounds can be 
>> included; so far I've only tried copper. This is a solid transparent well 
>> adhered layer, not some powdered composite. I really don't know what to do 
>> with this, probably nothing. Thought you might be interested anyway.
>>
>> --- Original Message ---
>> On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg 
>>  wrote:
>>
>>> Foster,
>>>
>>> You have raised an interesting possibility. I have been out of the loop for 
>>> 25 years, so my info may be dated. However, the cerium was included in the 
>>> melt, with the quantity a djusted for the optimum UV absorption for the 
>>> coverslide thickness.
>>>
>>> Use of a doped layer rather than the bulk could possibly provide some 
>>> improved optical matching in the "STACK". It would have to be tested for 
>>> stability during the thermal cycles. If the surface doping (by dipping or 
>>> by ion implantation) is a reliable process, this might be worth mentioning 
>>> it to the appropriate people (who I no longer know).
>>>
>>> Andrew
>>>
>>> -- Forwarded message -
>>>
>>> I guess this is getting off into the weeds a bit, but is the quartz layer 
>>> doped with cerium in the mass? Or is the cerium diffused into the surface 
>>> by immersion in a molten cerium compound?
>>>
>>> --
>>> On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
>>>  wrote:
>>>
>>

Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread Robin
In reply to  MSF's message of Tue, 20 Dec 2022 22:59:35 +:
Hi Michael,

>I recently discovered a method of depositing a layer of silica on any given 
>surface using a ridiculously simple and inexpensive technique. This is 
>something that should have been discovered 200 or so years ago, but wasn't. 
>I've searched for months trying to find out if this was done before, but I 
>find no reference to it. The silica layer deposited is only a few tens of 
>microns thick, but the process can be repeated. Other compounds can be 
>included; so far I've only tried copper. This is a solid transparent well 
>adhered layer, not some powdered composite. I really don't know what to do 
>with this, probably nothing. Thought you might be interested anyway.

...take out a patent? Then any one interested will let you know in short order. 
:)

Cloud storage:-

Unsafe, Slow, Expensive 

...pick any three.



Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread Andrew Meulenberg
Things have gone beyond simple UV protection. At a quick glance, I found
this from 2014:
"Ion exchange doping of solar cell coverglass for sunlight down-shifting"
https://scholar.google.com/scholar_url?url=https://www.academia.edu/download/39434467/Ion_exchange_doping_of_solar_cell_coverg20151026-13237-11ddof9.pdf=en=X=jkyiY7KwAY6yyATvqZyoBQ=AAGBfm2yTEGoICv5hlwEB0RulQA-SecuDg=scholarr

On Tue, Dec 20, 2022 at 4:59 PM MSF  wrote:

>
> I was working with this method of surface treatment of glass more decades
> ago than I care to remember. You simply  immerse ordinary glass into a bath
> of molten potassium nitrate and the sodium Ions at the surface are replaced
> with potassium ions, resulting in a highly impact resistant glass. These
> days it's called gorilla glass, but I was using this technique long before
> Corning.
>
> I see that  cerium doped sheet is just glass, not fused silica. So it may
> be that no cerium ions could be implanted into pure silica by the molten
> salt technique.
>
> I recently discovered a method of depositing a layer of silica on any
> given surface using a ridiculously simple and inexpensive technique. This
> is something that should have been discovered 200 or so years ago, but
> wasn't. I've searched for months trying to find out if this was done
> before, but I find no reference to it. The silica layer deposited is only a
> few tens of microns thick, but the process can be repeated. Other compounds
> can be included; so far I've only tried copper. This is a solid transparent
> well adhered layer, not some powdered composite.  I really don't know what
> to do with this, probably nothing. Thought you might be interested anyway.
>
> --- Original Message ---
> On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg <
> mules...@gmail.com> wrote:
>
> Foster,
> You have raised an interesting possibility. I have been out of the loop
> for 25 years, so my info may be dated. However, the cerium was included in
> the melt, with the quantity a djusted for the optimum UV absorption for the
> coverslide thickness.
>
> Use of a doped layer rather than the bulk could possibly provide some
> improved optical matching in the "STACK". It would have to be tested for
> stability during the thermal cycles. If the surface doping (by dipping or
> by ion implantation) is a reliable process, this might be worth mentioning
> it to the appropriate people (who I no longer know).
>
> Andrew
>
> -- Forwarded message -
>
>
> I guess this is getting off into the weeds a bit, but is the quartz layer
> doped with cerium in the mass? Or is the cerium diffused into the surface
> by immersion in a molten cerium compound?
>
> --
> On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg <
> mules...@gmail.com> wrote:
>
>
>> >
>>
>>
>
>


Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread MSF
I was working with this method of surface treatment of glass more decades ago 
than I care to remember. You simply immerse ordinary glass into a bath of 
molten potassium nitrate and the sodium Ions at the surface are replaced with 
potassium ions, resulting in a highly impact resistant glass. These days it's 
called gorilla glass, but I was using this technique long before Corning.

I see that cerium doped sheet is just glass, not fused silica. So it may be 
that no cerium ions could be implanted into pure silica by the molten salt 
technique.

I recently discovered a method of depositing a layer of silica on any given 
surface using a ridiculously simple and inexpensive technique. This is 
something that should have been discovered 200 or so years ago, but wasn't. 
I've searched for months trying to find out if this was done before, but I find 
no reference to it. The silica layer deposited is only a few tens of microns 
thick, but the process can be repeated. Other compounds can be included; so far 
I've only tried copper. This is a solid transparent well adhered layer, not 
some powdered composite. I really don't know what to do with this, probably 
nothing. Thought you might be interested anyway.

--- Original Message ---
On Tuesday, December 20th, 2022 at 10:00 PM, Andrew Meulenberg 
 wrote:

> Foster,
>
> You have raised an interesting possibility. I have been out of the loop for 
> 25 years, so my info may be dated. However, the cerium was included in the 
> melt, with the quantity a djusted for the optimum UV absorption for the 
> coverslide thickness.
>
> Use of a doped layer rather than the bulk could possibly provide some 
> improved optical matching in the "STACK". It would have to be tested for 
> stability during the thermal cycles. If the surface doping (by dipping or by 
> ion implantation) is a reliable process, this might be worth mentioning it to 
> the appropriate people (who I no longer know).
>
> Andrew
>
> -- Forwarded message -
>
> I guess this is getting off into the weeds a bit, but is the quartz layer 
> doped with cerium in the mass? Or is the cerium diffused into the surface by 
> immersion in a molten cerium compound?
>
> --
> On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
>  wrote:
>


Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread Andrew Meulenberg
Foster,
You have raised an interesting possibility. I have been out of the loop for
25 years, so my info may be dated. However, the cerium was included in the
melt, with the quantity a djusted for the optimum UV absorption for the
coverslide thickness.

Use of a doped layer rather than the bulk could possibly provide some
improved optical matching in the "STACK". It would have to be tested for
stability during the thermal cycles. If the surface doping (by dipping or
by ion implantation) is a reliable process, this might be worth mentioning
it to the appropriate people (who I no longer know).

Andrew

-- Forwarded message -
From: MSF 
Date: Tue, Dec 20, 2022 at 1:23 PM
Subject: Re: [Vo]:Solar cell lifetime in space
To: 


I guess this is getting off into the weeds a bit, but is the quartz layer
doped with cerium in the mass? Or is the cerium diffused into the surface
by immersion in a molten cerium compound?

--- Original Message ---
On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg <
mules...@gmail.com> wrote:

Robin,

The whole deal is a set of tradeoffs that depends on the environment to be
encountered. At some altitudes, the Van Allen Belts have too much
penetrating radiation to allow solar cells to be used for long-term
missions.

Addition of coverslides makes the solarcell assembly vulnerable to solar
ultra-violet radiation. It is necessary to use high-purity fused silica for
the coverslides to prevent themselves from being damaged by the UV. But
these coverslides allow the UV to damage the adhesive that holds them to
the solar cells. Thus, it is necessary to put a UV filter on these
coverslides. The UV filters can be damaged by the trapped-proton
environment if there is a manufacturing error. Cerium-doped microsheet
(CMS) is generally used for coverslides because it does not transmit the UV
that can damage the special adhesives (flexible conformal coatings) that
can function through the thermal excursions experienced when the spacecraft
enters and exits the Earth's shadow. However, the CMS cutting out the
damaging UV also lowers the starting efficiency of the solar arrays that
can derive energy from the UV.

It is a tradeoff that must even recognize the possibility of solar flares
that, when extreme and aimed at the earth, can cause more damage (in days)
than all of the other sources of degradation over the rest of the mission.
The tradeoff is further complicated by the variety of cells and materials
(filters and coverslides) available. There is also the mission variables
that are sometimes of greatest concern. Sometimes it is more important to
have max power at the beginning of a mission; sometimes at the end.

It was a portion of my job for nearly 30 years.

Andrew
_ _ _

On Mon, Dec 19, 2022 at 12:41 PM Robin 
wrote

> In reply to Andrew Meulenberg's message of Mon, 19 Dec 2022 00:25:20 -0600:
> Hi Andrew,
>
> I'm sure it does, however the high energy particles from other sources are
> also present, so it seems to be fairly
> effective against them too? Otherwise surely it would have been noticed
> that cells in space deteriorate rapidly?
>
>
> >Robin,
> >
> >This thickness of coverslide stops the low-energy trapped protons of the
> >Van Allen belts that would cut the cell efficiency by ~30% in not too many
> >months.
> >
> >Andrew
> [snip]
> Cloud storage:-
>
> Unsafe, Slow, Expensive
>
> ...pick any three.
>
>


Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread Robin
In reply to  Andrew Meulenberg's message of Mon, 19 Dec 2022 20:26:52 -0600:
Hi Andrew,

Thanks for the info. It's nice to have comment from an "insider". :)

>Robin,
>
>The whole deal is a set of tradeoffs that depends on the environment to be
>encountered. At some altitudes, the Van Allen Belts have too much
>penetrating radiation to allow solar cells to be used for long-term
>missions.
>
>Addition of coverslides makes the solarcell assembly vulnerable to solar
>ultra-violet radiation. It is necessary to use high-purity fused silica for
>the coverslides to prevent themselves from being damaged by the UV. But
>these coverslides allow the UV to damage the adhesive that holds them to
>the solar cells. Thus, it is necessary to put a UV filter on these
>coverslides. The UV filters can be damaged by the trapped-proton
>environment if there is a manufacturing error. Cerium-doped microsheet
>(CMS) is generally used for coverslides because it does not transmit the UV
>that can damage the special adhesives (flexible conformal coatings) that
>can function through the thermal excursions experienced when the spacecraft
>enters and exits the Earth's shadow. However, the CMS cutting out the
>damaging UV also lowers the starting efficiency of the solar arrays that
>can derive energy from the UV.
>
>It is a tradeoff that must even recognize the possibility of solar flares
>that, when extreme and aimed at the earth, can cause more damage (in days)
>than all of the other sources of degradation over the rest of the mission.
>The tradeoff is further complicated by the variety of cells and materials
>(filters and coverslides) available. There is also the mission variables
>that are sometimes of greatest concern. Sometimes it is more important to
>have max power at the beginning of a mission; sometimes at the end.
>
>It was a portion of my job for nearly 30 years.
>
>Andrew
[snip]
Cloud storage:-

Unsafe, Slow, Expensive 

...pick any three.



Re: [Vo]:Solar cell lifetime in space

2022-12-20 Thread MSF
I guess this is getting off into the weeds a bit, but is the quartz layer doped 
with cerium in the mass? Or is the cerium diffused into the surface by 
immersion in a molten cerium compound?

--- Original Message ---
On Tuesday, December 20th, 2022 at 2:26 AM, Andrew Meulenberg 
 wrote:

> Robin,
>
> The whole deal is a set of tradeoffs that depends on the environment to be 
> encountered. At some altitudes, the Van Allen Belts have too much penetrating 
> radiation to allow solar cells to be used for long-term missions.
>
> Addition of coverslides makes the solarcell assembly vulnerable to solar 
> ultra-violet radiation. It is necessary to use high-purity fused silica for 
> the coverslides to prevent themselves from being damaged by the UV. But these 
> coverslides allow the UV to damage the adhesive that holds them to the solar 
> cells. Thus, it is necessary to put a UV filter on these coverslides. The UV 
> filters can be damaged by the trapped-proton environment if there is a 
> manufacturing error. Cerium-doped microsheet (CMS) is generally used for 
> coverslides because it does not transmit the UV that can damage the special 
> adhesives (flexible conformal coatings) that can function through the thermal 
> excursions experienced when the spacecraft enters and exits the Earth's 
> shadow. However, the CMS cutting out the damaging UV also lowers the starting 
> efficiency of the solar arrays that can derive energy from the UV.
>
> It is a tradeoff that must even recognize the possibility of solar flares 
> that, when extreme and aimed at the earth, can cause more damage (in days) 
> than all of the other sources of degradation over the rest of the mission. 
> The tradeoff is further complicated by the variety of cells and materials 
> (filters and coverslides) available. There is also the mission variables that 
> are sometimes of greatest concern. Sometimes it is more important to have max 
> power at the beginning of a mission; sometimes at the end.
>
> It was a portion of my job for nearly 30 years.
>
> Andrew
> _ _ _
> On Mon, Dec 19, 2022 at 12:41 PM Robin  
> wrote
>
>> In reply to Andrew Meulenberg's message of Mon, 19 Dec 2022 00:25:20 -0600:
>> Hi Andrew,
>>
>> I'm sure it does, however the high energy particles from other sources are 
>> also present, so it seems to be fairly
>> effective against them too? Otherwise surely it would have been noticed that 
>> cells in space deteriorate rapidly?
>>
>>>Robin,
>>>
>>>This thickness of coverslide stops the low-energy trapped protons of the
>>>Van Allen belts that would cut the cell efficiency by ~30% in not too many
>>>months.
>>>
>>>Andrew
>> [snip]
>> Cloud storage:-
>>
>> Unsafe, Slow, Expensive
>>
>> ...pick any three.

Re: [Vo]:Solar cell lifetime in space

2022-12-19 Thread Andrew Meulenberg
Robin,

The whole deal is a set of tradeoffs that depends on the environment to be
encountered. At some altitudes, the Van Allen Belts have too much
penetrating radiation to allow solar cells to be used for long-term
missions.

Addition of coverslides makes the solarcell assembly vulnerable to solar
ultra-violet radiation. It is necessary to use high-purity fused silica for
the coverslides to prevent themselves from being damaged by the UV. But
these coverslides allow the UV to damage the adhesive that holds them to
the solar cells. Thus, it is necessary to put a UV filter on these
coverslides. The UV filters can be damaged by the trapped-proton
environment if there is a manufacturing error. Cerium-doped microsheet
(CMS) is generally used for coverslides because it does not transmit the UV
that can damage the special adhesives (flexible conformal coatings) that
can function through the thermal excursions experienced when the spacecraft
enters and exits the Earth's shadow. However, the CMS cutting out the
damaging UV also lowers the starting efficiency of the solar arrays that
can derive energy from the UV.

It is a tradeoff that must even recognize the possibility of solar flares
that, when extreme and aimed at the earth, can cause more damage (in days)
than all of the other sources of degradation over the rest of the mission.
The tradeoff is further complicated by the variety of cells and materials
(filters and coverslides) available. There is also the mission variables
that are sometimes of greatest concern. Sometimes it is more important to
have max power at the beginning of a mission; sometimes at the end.

It was a portion of my job for nearly 30 years.

Andrew
_ _ _

On Mon, Dec 19, 2022 at 12:41 PM Robin 
wrote

> In reply to  Andrew Meulenberg's message of Mon, 19 Dec 2022 00:25:20
> -0600:
> Hi Andrew,
>
> I'm sure it does, however the high energy particles from other sources are
> also present, so it seems to be fairly
> effective against them too? Otherwise surely it would have been noticed
> that cells in space deteriorate rapidly?
>
>
> >Robin,
> >
> >This thickness of coverslide stops the low-energy trapped protons of the
> >Van Allen belts that would cut the cell efficiency by ~30% in not too many
> >months.
> >
> >Andrew
> [snip]
> Cloud storage:-
>
> Unsafe, Slow, Expensive
>
> ...pick any three.
>
>


Re: [Vo]:Solar cell lifetime in space

2022-12-19 Thread Robin
In reply to  Andrew Meulenberg's message of Mon, 19 Dec 2022 00:25:20 -0600:
Hi Andrew,

I'm sure it does, however the high energy particles from other sources are also 
present, so it seems to be fairly
effective against them too? Otherwise surely it would have been noticed that 
cells in space deteriorate rapidly?


>Robin,
>
>This thickness of coverslide stops the low-energy trapped protons of the
>Van Allen belts that would cut the cell efficiency by ~30% in not too many
>months.
>
>Andrew
[snip]
Cloud storage:-

Unsafe, Slow, Expensive 

...pick any three.



Re: [Vo]:Solar cell lifetime in space

2022-12-18 Thread Andrew Meulenberg
Robin,

This thickness of coverslide stops the low-energy trapped protons of the
Van Allen belts that would cut the cell efficiency by ~30% in not too many
months.

Andrew


On Sun, Dec 18, 2022 at 6:38 PM Robin 
wrote:

> Hi,
>
> ESA apparently place a 0.1 mm layer of glass before their solar cells, to
> protect them from radiation. This gives them a
> projected lifetime of 15 years according to
>
> https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Inside_a_solar_cell
>
> Cloud storage:-
>
> Unsafe, Slow, Expensive
>
> ...pick any three.
>
>