RE: EXTERNAL: Re: [Vo]:DCE for SPP

[Roarty, Francis X]

Axil, well put! It is exactly as you say " that perhaps insufficient
consideration may have been given to the integration with the larger system." , 
the mainstream considers the isotropy of open space a sort of ground state 
because virtual particles and Casimir effect were not considered. Nano regions 
can be suppressed via Casimir effect to attain vacuum densities far lower than 
we observe at the macro scale. Mainstream only wants to consider changes in 
vacuum density / inertial frames as a functions of relativistic acceleration or 
equivalent acceleration adhering to square law.
Fran

-Original Message-
From: mix...@bigpond.com [mailto:mix...@bigpond.com] 
Sent: Thursday, February 11, 2016 4:44 PM
To: vortex-l@eskimo.com
Subject: EXTERNAL: Re: [Vo]:DCE for SPP

In reply to  Axil Axil's message of Wed, 10 Feb 2016 21:53:18 -0500:
Hi,
[snip]
>Let us get to the bottom of this fear. Expand...

It depends on exactly what is meant by negative energy. If meant in an absolute
sense, then I am very doubtful. However if it's just a consequence of only
considering too small a system (i.e. where the boundaries are chosen too small),
then I have no problem with it, other than that perhaps insufficient
consideration may have been given to the integration with the larger system.


>
>On Wed, Feb 10, 2016 at 9:36 PM,  wrote:
>
>> In reply to  Axil Axil's message of Tue, 9 Feb 2016 20:04:51 -0500:
>> Hi,
>> [snip]
>> >Do you believe the the Penrose mechanism can also add a multiplier effect
>> >to the extraction of energy from the vacuum in the dark mode SPP?
>> >
>> >https://en.wikipedia.org/wiki/Penrose_process
>>
>> I'm always a bit suspicious of theories that make use of "negative energy".
>> Regards,
>>
>> Robin van Spaandonk
>>
>> http://rvanspaa.freehostia.com/project.html
>>
>>
Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html

Re: [Vo]:DCE for SPP

[Axil Axil]

If the vacuum can be induced to generate more virtual particle production
in one location then another location of the vacuum must produce less
virtual particle production to keep the average energy production of the
vacuum zero.

The suppression of virtual particles through this unbalancing method is
termed negative vacuum energy.

On Thu, Feb 11, 2016 at 4:53 PM, Eric Walker  wrote:

> On Thu, Feb 11, 2016 at 3:38 PM,  wrote:
>
> >It's what is needed to do negative work.
>>
>> Is that work, that once having been done, requires even more work to fix
>> up the
>> result? :)
>>
>
> I was wondering what it was myself. :)  It was fun to think about.  Now I
> see why the physicists wanted to say that negative energy is unphysical.
>
> Eric
>
>

Re: [Vo]:DCE for SPP

[Eric Walker]

On Thu, Feb 11, 2016 at 3:38 PM,  wrote:

>It's what is needed to do negative work.
>
> Is that work, that once having been done, requires even more work to fix
> up the
> result? :)
>

I was wondering what it was myself. :)  It was fun to think about.  Now I
see why the physicists wanted to say that negative energy is unphysical.

Eric

Re: [Vo]:DCE for SPP

[mixent]

In reply to  Axil Axil's message of Wed, 10 Feb 2016 21:53:18 -0500:
Hi,
[snip]
>Let us get to the bottom of this fear. Expand...

It depends on exactly what is meant by negative energy. If meant in an absolute
sense, then I am very doubtful. However if it's just a consequence of only
considering too small a system (i.e. where the boundaries are chosen too small),
then I have no problem with it, other than that perhaps insufficient
consideration may have been given to the integration with the larger system.


>
>On Wed, Feb 10, 2016 at 9:36 PM,  wrote:
>
>> In reply to  Axil Axil's message of Tue, 9 Feb 2016 20:04:51 -0500:
>> Hi,
>> [snip]
>> >Do you believe the the Penrose mechanism can also add a multiplier effect
>> >to the extraction of energy from the vacuum in the dark mode SPP?
>> >
>> >https://en.wikipedia.org/wiki/Penrose_process
>>
>> I'm always a bit suspicious of theories that make use of "negative energy".
>> Regards,
>>
>> Robin van Spaandonk
>>
>> http://rvanspaa.freehostia.com/project.html
>>
>>
Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html

Re: [Vo]:DCE for SPP

[mixent]

In reply to  Eric Walker's message of Wed, 10 Feb 2016 21:15:18 -0600:
Hi,
[snip]
>On Wed, Feb 10, 2016 at 8:36 PM,  wrote:
>
>I'm always a bit suspicious of theories that make use of "negative energy".
>>
>
>It's what is needed to do negative work.

Is that work, that once having been done, requires even more work to fix up the
result? :)

>
>Eric
Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html

RE: [Vo]:DCE for SPP

[Jones Beene]

From: Roarty, Francis X 

*   Perhaps vacuum energy cannot perform measurable work at our typical 
physical macro velocities relative to C …

Well, it is pretty clear from the literature, starting in 2011 and continuing 
to recent papers - that the DCE the dynamical Casimir effect - can and does 
function to convert virtual photons into real photons. 

Even if we define the photon as massless, this is “work” by most definitions 
even if the base-level effect may not appear like mass is being moved. This 
distinction is mainly semantics, since excess energy from photons has a 
mass-equivalent. There are dozens of DCE papers, starting here. The point is 
the effect is proved in experiment and theory.

https://www.technologyreview.com/s/424111/first-observation-of-the-dynamical-casimir-effect/

http://arxiv.org/abs/1105.4714

Beyond that, we have to extrapolate beyond a weak effect requiring a 
superconductor to a robust effect of the SPP in combination with DCE, requiring 
no superconductor (or HTSC). If SPP operates as the paper claims, to convert 
one real photon into two real photons (photon doubling) and DCE gives real 
photons from virtual photons, and the translucent ceramic stores photons, then 
we have set the stage of a “photon chain reaction.” 

Typically the term “photon chain reaction” turns up in descriptions of lasers. 
The glow-stick can be analogized to a semi-coherent type of IR laser where 
there is one predominant IR emission line and lots of secondary light which is 
not coherent. We could call it a superradiant laser.

With any chain reaction, the output grows exponentially. Even if the 
incandescent light source is only 5% efficient initially (it is probably less), 
then net gain is still possible if there is sufficient doubling of photons due 
to the DCE/SPP mechanism.

This MO of photon chain reaction - may sound preposterous to those who are 
invested in nuclear fusion as the source of gain in the glow-stick (assuming 
Parkhomov can be replicated)… but it is crystal clear from actual results that 
in fact, it is far more preposterous to suggest fusion as the main source of 
gain. 

There is little indicia of fusion whereas DCE is proved in both experiment and 
theory. Real fusion in a Parkhomov tube is not proved in either theory or 
experiment. However, transmutation of elements could be a side effect of 
harnessing vacuum energy even if no fusion happens.

BTW – by most definitions of ZPE and its effect on electrons, especially 
Puthoff’s, it is clear that the Mills-effect, or fractional hydrogen, or 
UDD/UDH, or DDL, etc… these are ALL zero point effects - and the energy 
essentially comes from the same virtual photon conversion process as does DCE.

Jones

Re: [Vo]:DCE for SPP

[Roarty, Francis X]

Axil,
Perhaps vacuum energy cannot perform measurable work at our typical physical 
macro velocities  relative to C but  vacuum wavelengths / virtual particle 
density does define inertial frames and ,IMHO, can do work if you are not 
outputting reaction mass to push an object toward C. My point is that if you 
harness DCE to move objects between different frames of negative portions of C 
where vacuum density is instead subtracted between different negative values by 
Casimir suppression you get these regions of equivalent negative accelerations 
for free as a property of the lattice defects and quantum geometry,  and the 
normally un-exploitable property of HUP [random motion of gas] accumulates as 
it moves the atoms between these regions forcing a spatial imbalance where they 
start to contract in what I am convinced is actually a negative form of 
Lorentzian contraction and time dilation that fits the claimed anomalies for 
both f/h and tritium. Naudts should have pursued his 2005 math paper further 
but he did endorse the hydrino telling me he understood the implications but 
was afraid to go out on the limb. I continue to endorse a view that these 
negative vacuum regions can be as relativistic wrt open space as, open space is 
to the gravity well of an event horizon, but now the isotropy [vacuum density] 
is re-defined as the difference between the square law of gravitation and  
inverse cube of Casimir suppression. In this definition the hydrogen is able to 
exploit the previously un-exploitable property of random motion [HUP trap] to 
move between these negative frames whereas a positive equivalent would require 
rocket fuel to attain different frames in a gravity well. I believe there then 
exists a set stage for “building” a Heisenberg trap [Maxwellian demon of sorts] 
but nature will always take the path of least resistance and contracted 
hydrogen will forever move through these negative regions avoiding work unless 
we limit their paths and force its motion to perform work.
I suspect the orbitals of f/h molecules oppose changes between inertial frames 
while atoms move freely and after disassociation the atoms reform new molecules 
at whatever inertial region they happen to occupy when they meet just waiting 
for random motion to move them away to regions where their contraction level 
opposes the local density enough to again disassociate the molecule and start 
the cycle over again. Photons from this process are very likely the key to 
engineering this process into a positive loop instead of nature’s desire to 
damp out and seek the easy path but SPP and resonance are beyond my skill set.
Fran


From: Axil Axil [mailto:janap...@gmail.com]
Sent: Wednesday, February 10, 2016 10:18 PM
To: vortex-l 
Subject: EXTERNAL: Re: [Vo]:DCE for SPP

I don't believe that the vacuum does work.

On Wed, Feb 10, 2016 at 10:15 PM, Eric Walker 
mailto:eric.wal...@gmail.com>> wrote:
On Wed, Feb 10, 2016 at 8:36 PM, 
mailto:mix...@bigpond.com>> wrote:

I'm always a bit suspicious of theories that make use of "negative energy".

It's what is needed to do negative work.

Eric

RE: [Vo]:DCE for SPP

[Russ George]

What, you don’t believe Casimir’s oxen pull?

 

From: Axil Axil [mailto:janap...@gmail.com] 
Sent: Wednesday, February 10, 2016 7:18 PM
To: vortex-l
Subject: Re: [Vo]:DCE for SPP

 

I don't believe that the vacuum does work.

 

On Wed, Feb 10, 2016 at 10:15 PM, Eric Walker mailto:eric.wal...@gmail.com> > wrote:

On Wed, Feb 10, 2016 at 8:36 PM, mailto:mix...@bigpond.com> > wrote:

 

I'm always a bit suspicious of theories that make use of "negative energy".

 

It's what is needed to do negative work.

 

Eric

 

 

Re: [Vo]:DCE for SPP

[Axil Axil]

I don't believe that the vacuum does work.

On Wed, Feb 10, 2016 at 10:15 PM, Eric Walker  wrote:

> On Wed, Feb 10, 2016 at 8:36 PM,  wrote:
>
> I'm always a bit suspicious of theories that make use of "negative energy".
>>
>
> It's what is needed to do negative work.
>
> Eric
>
>

Re: [Vo]:DCE for SPP

[Eric Walker]

On Wed, Feb 10, 2016 at 8:36 PM,  wrote:

I'm always a bit suspicious of theories that make use of "negative energy".
>

It's what is needed to do negative work.

Eric

Re: [Vo]:DCE for SPP

[Axil Axil]

Let us get to the bottom of this fear. Expand...

On Wed, Feb 10, 2016 at 9:36 PM,  wrote:

> In reply to  Axil Axil's message of Tue, 9 Feb 2016 20:04:51 -0500:
> Hi,
> [snip]
> >Do you believe the the Penrose mechanism can also add a multiplier effect
> >to the extraction of energy from the vacuum in the dark mode SPP?
> >
> >https://en.wikipedia.org/wiki/Penrose_process
>
> I'm always a bit suspicious of theories that make use of "negative energy".
> Regards,
>
> Robin van Spaandonk
>
> http://rvanspaa.freehostia.com/project.html
>
>

Re: [Vo]:DCE for SPP

[mixent]

In reply to  Axil Axil's message of Tue, 9 Feb 2016 20:04:51 -0500:
Hi,
[snip]
>Do you believe the the Penrose mechanism can also add a multiplier effect
>to the extraction of energy from the vacuum in the dark mode SPP?
>
>https://en.wikipedia.org/wiki/Penrose_process

I'm always a bit suspicious of theories that make use of "negative energy".
Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html

Re: [Vo]:DCE for SPP

[Axil Axil]

Do you believe the the Penrose mechanism can also add a multiplier effect
to the extraction of energy from the vacuum in the dark mode SPP?

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

On Tue, Feb 9, 2016 at 7:50 PM,  wrote:

> In reply to  Axil Axil's message of Tue, 9 Feb 2016 12:56:48 -0500:
> Hi,
> [snip]
> >All those references to order of magnitude increases sound like over
> unity amplification of incoming photons.
>
> The original number is 1E-6, i.e. 1 in a million. Hence even orders of
> magnitude
> improvement doesn't even get you to 1, let alone OU.
>
> Regards,
>
> Robin van Spaandonk
>
> http://rvanspaa.freehostia.com/project.html
>
>

Re: [Vo]:DCE for SPP

[mixent]

In reply to  Axil Axil's message of Tue, 9 Feb 2016 12:56:48 -0500:
Hi,
[snip]
>All those references to order of magnitude increases sound like over unity 
>amplification of incoming photons.

The original number is 1E-6, i.e. 1 in a million. Hence even orders of magnitude
improvement doesn't even get you to 1, let alone OU.

Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html

RE: [Vo]:DCE for SPP

[Jones Beene]

This could be the sleeper paper of the year. Photon multiplication in an 
incandescent cell - due to DCE/SPP would be a mechanism which changes the whole 
ball game, if true. As they snidely quip on SNL: Who knew?

BTW - this M.O. explains how the Lugano results, as clarified by Bob Higgins to 
COP~1.5 over 30 days, could have resulted from so low an inventory of hydrogen. 
In fact, the gain would have been the same with no fuel if SPP are supplying it 
! 

Simply stated, the gain from the incandescent glow-stick type of reactor can be 
the result of photon multiplication during SPP formation. The nickel and 
hydrogen can be superfluous. The main requirement is a nanoporous optically 
translucent ceramic and an electrically charged heater coil which can reach 
incandescence. The energy comes from the Dynamic Casimir Effect – which is the 
same as saying, from the zero point field.

In a side-by-side test, like the one which Alan Goldwater has been running, the 
null side will be as gainful as the loaded side (…if there is gain at all, but 
the results give the appearance of no gain).

From: Axil 

*   All those references to order of magnitude increases sound like over 
unity amplification of incoming photons.

Jones Beene wrote:
“Dynamical Casimir effect for surface plasmon polaritons”
The title says it all, in terms of hitting on two of the significant new 
catch-phrases which are cropping up in the glow-stick version of LENR, but the 
paper (from Estonia) is behind a paywall…
http://www.sciencedirect.com/science/article/pii/S0375960114012195
Ostensibly, it would explain how the SPP can become excessively energetic in 
circumstances which are relatively mundane. One message that is emerging is 
that SPP formation could be gainful in itself, despite whatever happens next. 
One photon going in with two coming out… provides a mechanism for gain if the 
wavelength is the same.
Abstract
The emission of photon pairs by a metal–dielectric interface placed between the 
mirrors of the resonator and excited by a plane wave is considered. The 
excitation causes oscillations in time of the optical length of surface plasmon 
polaritons in the interface. This leads to the dynamical Casimir effect – the 
generation of pairs of surface plasmon polariton quanta, which transfer to 
photons outside the interface. In the case of a properly chosen interface, the 
yield of two-photon emission may exceed that of the usual spontaneous 
parametric down-conversion.

Re: [Vo]:DCE for SPP

[Axil Axil]

http://arxiv.org/ftp/arxiv/papers/1410/1410.4413.pdf

Dynamical Casimir effect for surface plasmon polaritons V. Hizhnyakov, A.
Loot, S.Ch.

 Azizabadi Institute of Physics, University of Tartu, Ravila 14c, 50411
Tartu, Estonia E-mail: h...@fi.tartu.ee

Abstract.

Emission of photon pairs by an interface of asymmetric dielectric and thin
metal film excited by a normally falling plane wave is considered. The
excitation causes oscillations in time of the phase velocity of surface
plasmon polaritons in the interface. This leads to the dynamical Casimir
effect – the generation of pairs of surface plasmon polariton quanta, which
transfer to photons outside the interface. In case of a properly chosen
interface, the yield of two-photon emission may exceed that of usual
spontaneous parametric down conversion.


7. Concluding remarks

A theoretical consideration of the dynamical Casimir effect in a
metal-dielectric interface with asymmetric dielectric is presented. It is
shown that the enhancement of the field of surface plasmon polaritons in
the interface may allow one to generate photon pairs with remarkable yield
of the order of 6 10 or more. The efficiency of the dynamical Casimir
effect in a metal-dielectric interface could be additionally enhanced a few
orders of magnitude if to use a proper grating: in addition to the
enhancement of the field of generated surface plasmon polaritons this would
allow one to enhance the field of excitation as well. One more possibility
to enhance the efficiency of the process under consideration is to surround
the metallic film by layers of dielectric crystals with enhanced second
order susceptibility. As examples of such crystals may serve AgGaSe2 and
NiNbO3, where (2)  30 pm/V [26]. It is expected that analogous value of
(2)  should have chalcopyrite compounds [27]. Moreover hetero-structures
with asymmetric quantum wells presumably may have (2)   400 pm/V [28].
This may allow one to additionally increase the yield  of the process a
few orders of magnitude. It is not excluded that the dynamical Casimir
effect in metal-dielectric interfaces may allow one to achieve full
conversion of incident photons to photon pairs.

All those references to order of magnitude increases sound like over unity
amplification of incoming photons.

On Tue, Feb 9, 2016 at 11:16 AM, Jones Beene  wrote:

> “Dynamical Casimir effect for surface plasmon polaritons”
>
> The title says it all, in terms of hitting on two of the significant new
> catch-phrases which are cropping up in the glow-stick version of LENR,
> but the paper (from Estonia) is behind a paywall…
>
> *http://www.sciencedirect.com/science/article/pii/S0375960114012195*
> 
>
> Ostensibly, it would explain how the SPP can become excessively energetic
> in circumstances which are relatively mundane. One message that is
> emerging is that SPP formation could be gainful in itself, despite
> whatever happens next. One photon going in with two coming out… provides a
> mechanism for gain if the wavelength is the same.
>
> *Abstract*
>
> The emission of photon pairs by a metal–dielectric interface placed
> between the mirrors of the resonator and excited by a plane wave is
> considered. The excitation causes oscillations in time of the optical
> length of surface plasmon polaritons in the interface. This leads to the
> dynamical Casimir effect – the generation of pairs of surface plasmon
> polariton quanta, which transfer to photons outside the interface. In the
> case of a properly chosen interface, the yield of two-photon emission may
> exceed that of the usual spontaneous parametric down-conversion.
>
>

RE: [Vo]:DCE for SPP

[Roarty, Francis X]

Jones,
can you view this?   
http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.113.093602
it looks like an earlier version that isn't behind a pay wall.
Fran



From: Jones Beene [mailto:jone...@pacbell.net]
Sent: Tuesday, February 09, 2016 11:31 AM
To: vortex-l@eskimo.com
Subject: EXTERNAL: RE: [Vo]:DCE for SPP

Here is another paper which reinforces the previous one... (wrt DCE being 
relevant to understanding one form of LENR - the glow-stick version)

"The dynamical Casimir effect generates entanglement" Felicetti, S et al
http://meetings.aps.org/Meeting/MAR14/Session/J28.11

"The existence of vacuum fluctuations, i.e., the presence of virtual particles 
in empty space, represents one of the most distinctive results of quantum 
mechanics. It is also known, under the name of dynamical Casimir effect, that 
fast-oscillating boundary conditions can generate real excitations out of the 
vacuum fluctuations."

Long-awaited, the first experimental demonstration of this phenomenon has been 
realized only recently, in the framework of superconducting circuits [C. M. 
Wilson et al. Nature 479, 376-379 (2011)]. In this contribution, we will 
discuss novel theoretical results, showing that the dynamical Casimir effect 
can be exploited to generate bipartite and multipartite entanglement among 
qubits. We will also present a superconducting circuit design which can 
feasibly implement the model considered with current technology.


"Dynamical Casimir effect for surface plasmon polaritons"

The title says it all, in terms of hitting on two of the significant new 
catch-phrases which are cropping up in the glow-stick version of LENR, but the 
paper (from Estonia) is behind a paywall...

http://www.sciencedirect.com/science/article/pii/S0375960114012195

Ostensibly, it would explain how the SPP can become excessively energetic in 
circumstances which are relatively mundane. One message that is emerging is 
that SPP formation could be gainful in itself, despite whatever happens next. 
One photon going in with two coming out... provides a mechanism for gain if the 
wavelength is the same.

Abstract

The emission of photon pairs by a metal-dielectric interface placed between the 
mirrors of the resonator and excited by a plane wave is considered. The 
excitation causes oscillations in time of the optical length of surface plasmon 
polaritons in the interface. This leads to the dynamical Casimir effect - the 
generation of pairs of surface plasmon polariton quanta, which transfer to 
photons outside the interface. In the case of a properly chosen interface, the 
yield of two-photon emission may exceed that of the usual spontaneous 
parametric down-conversion.

RE: [Vo]:DCE for SPP

[Jones Beene]

Here is another paper which reinforces the previous one. (wrt DCE being
relevant to understanding one form of LENR - the glow-stick version)

 

"The dynamical Casimir effect generates entanglement" Felicetti, S et al

http://meetings.aps.org/Meeting/MAR14/Session/J28.11

 

"The existence of vacuum fluctuations, i.e., the presence of virtual
particles in empty space, represents one of the most distinctive results of
quantum mechanics. It is also known, under the name of dynamical Casimir
effect, that fast-oscillating boundary conditions can generate real
excitations out of the vacuum fluctuations." 

 

Long-awaited, the first experimental demonstration of this phenomenon has
been realized only recently, in the framework of superconducting circuits
[C. M. Wilson et al. Nature 479, 376-379 (2011)]. In this contribution, we
will discuss novel theoretical results, showing that the dynamical Casimir
effect can be exploited to generate bipartite and multipartite entanglement
among qubits. We will also present a superconducting circuit design which
can feasibly implement the model considered with current technology.



"Dynamical Casimir effect for surface plasmon polaritons"

The title says it all, in terms of hitting on two of the significant new
catch-phrases which are cropping up in the glow-stick version of LENR, but
the paper (from Estonia) is behind a paywall.

 
http://www.sciencedirect.com/science/article/pii/S0375960114012195

Ostensibly, it would explain how the SPP can become excessively energetic in
circumstances which are relatively mundane. One message that is emerging is
that SPP formation could be gainful in itself, despite whatever happens
next. One photon going in with two coming out. provides a mechanism for gain
if the wavelength is the same.

Abstract

The emission of photon pairs by a metal-dielectric interface placed between
the mirrors of the resonator and excited by a plane wave is considered. The
excitation causes oscillations in time of the optical length of surface
plasmon polaritons in the interface. This leads to the dynamical Casimir
effect - the generation of pairs of surface plasmon polariton quanta, which
transfer to photons outside the interface. In the case of a properly chosen
interface, the yield of two-photon emission may exceed that of the usual
spontaneous parametric down-conversion.

[Vo]:DCE for SPP

[Jones Beene]

"Dynamical Casimir effect for surface plasmon polaritons"

The title says it all, in terms of hitting on two of the significant new
catch-phrases which are cropping up in the glow-stick version of LENR, but
the paper (from Estonia) is behind a paywall.
http://www.sciencedirect.com/science/article/pii/S0375960114012195

Ostensibly, it would explain how the SPP can become excessively energetic in
circumstances which are relatively mundane. One message that is emerging is
that SPP formation could be gainful in itself, despite whatever happens
next. One photon going in with two coming out. provides a mechanism for gain
if the wavelength is the same.

Abstract
The emission of photon pairs by a metal-dielectric interface placed between
the mirrors of the resonator and excited by a plane wave is considered. The
excitation causes oscillations in time of the optical length of surface
plasmon polaritons in the interface. This leads to the dynamical Casimir
effect - the generation of pairs of surface plasmon polariton quanta, which
transfer to photons outside the interface. In the case of a properly chosen
interface, the yield of two-photon emission may exceed that of the usual
spontaneous parametric down-conversion.