In article <89212a08-f175-430d-bc50-497895c0caa4@googlegroups.com>,
"scottlowt...@ix.netcom.com" <scottlowt...@ix.netcom.com> wrote:
> The US Navy seems to have equipped one of its destroyers with a sizable > anti-aircraft laser weapon. Photo here:
> http://up-ship.com/blog/?p=15938
scottlowt...@ix.netcom.com wrote:
> The US Navy seems to have equipped one of its destroyers with a
> sizable anti-aircraft laser weapon. Photo here:
> http://up-ship.com/blog/?p=15938
A 33 kW Laser system just wont cut it against real threats,
the minimum delivered power for a useful system is considered
to be around 100 kW and with a typical 10% efficiency that
requires 1 M of electrical power. The rest of the 900kW is
dissipated as heat which will require a humongous cooling
system.
Then there is the little matter of absorption by smoke,
clouds etc.
> A 33 kW Laser system just wont cut it against real threats,
> the minimum delivered power for a useful system is considered
> to be around 100 kW and with a typical 10% efficiency that
> requires 1 M of electrical power. The rest of the 900kW is
> dissipated as heat which will require a humongous cooling
> system.
> Then there is the little matter of absorption by smoke,
> clouds etc.
> Keith
Cooling is very doable. After all, there is a huge ocean right adjacent. That little matter of absorption by smoke and water vapor depends on the laser wavelength, does it not? Also, the concentration of smoke and water vapor would factor in although admittedly for naval use, there's always water vapor around.
>> A 33 kW Laser system just wont cut it against real threats,
>> the minimum delivered power for a useful system is considered
>> to be around 100 kW and with a typical 10% efficiency that
>> requires 1 M of electrical power. The rest of the 900kW is
>> dissipated as heat which will require a humongous cooling
>> system.
>> Then there is the little matter of absorption by smoke,
>> clouds etc.
>> Keith
> Cooling is very doable. After all, there is a huge ocean right
> adjacent. That little matter of absorption by smoke and water vapor
> depends on the laser wavelength, does it not? Also, the
> concentration of smoke and water vapor would factor in although
> admittedly for naval use, there's always water vapor around.
> A 33 kW Laser system just wont cut it against real threats,
> the minimum delivered power for a useful system is considered
> to be around 100 kW and with a typical 10% efficiency that
> requires 1 M of electrical power.
Even a semi-lethal weapon might serve as a very welcome option to discourage low-tech threats such as speedboats.
> The rest of the 900kW is
> dissipated as heat which will require a humongous cooling
> system.
I assume that the weapon would only fire for seconds at a time, so all you would need is a good heat sink and a modest cooling system. Even a gun must absorb a huge amount of waste heat when it fires, yet we've been successfully using them for centuries now.
In article <IaMTr.558199$I_.103...@fx28.am4>,
"Keith W" <keithnospoofsple...@demon.co.uk> writes:
>A 33 kW Laser system just wont cut it against real threats,
>the minimum delivered power for a useful system is considered
>to be around 100 kW and with a typical 10% efficiency that
>requires 1 M of electrical power. The rest of the 900kW is
>dissipated as heat which will require a humongous cooling
>system.
How long do I have to deliver that 100 kW and/or what is
the spot size at the target?
What happens if the bad guy carefully polishes his toys so
it reflects most of the energy?
On Monday, August 6, 2012 3:32:25 AM UTC-6, Keith W wrote:
> the minimum delivered power for a useful system is considered
> to be around 100 kW and with a typical 10% efficiency that
> requires 1 M of electrical power.
The report is that the operational version - which the one in the photo probably isn't - will have a 100kW beam and 25% efficiency... 300kW of heat, likely dumped right into the ocean.
Such a laser system might to wonders towards mucking up satellites, which task the Navy has shown an interest in.
<scottlowt...@ix.netcom.com> wrote:
> On Monday, August 6, 2012 3:32:25 AM UTC-6, Keith W wrote:
> > the minimum delivered power for a useful system is considered
> > to be around 100 kW and with a typical 10% efficiency that
> > requires 1 M of electrical power.
> The report is that the operational version - which the one in the photo probably isn't - will have a 100kW beam and 25% efficiency... 300kW of heat, likely dumped right into the ocean.
> Such a laser system might to wonders towards mucking up satellites, which task the Navy has shown an interest in.
Good call! Like the "Cardinal of the Kremlin" array Tom Clancy
imagined in the (then) USSR.
> In article <IaMTr.558199$I_.103...@fx28.am4>,
> "Keith W" <keithnospoofsple...@demon.co.uk> writes:
>>A 33 kW Laser system just wont cut it against real threats,
>>the minimum delivered power for a useful system is considered
>>to be around 100 kW and with a typical 10% efficiency that
>>requires 1 M of electrical power. The rest of the 900kW is
>>dissipated as heat which will require a humongous cooling
>>system.
> How long do I have to deliver that 100 kW and/or what is
> the spot size at the target?
> What happens if the bad guy carefully polishes his toys so
> it reflects most of the energy?
you can never keep a surface totally clean and shiny,especially outdoors.
Lasers are always destroying their own mirrors if the mirrors are not cooled properly.
scottlowt...@ix.netcom.com wrote:
> The report is that the operational version - which the one in the
> photo probably isn't - will have a 100kW beam and 25% efficiency...
> 300kW of heat, likely dumped right into the ocean.
> Such a laser system might to wonders towards mucking up satellites,
> which task the Navy has shown an interest in.
300KW for how long -- a few seconds at most?
More likely, the peak power is for a fraction of a second for each
burst.
