WTB real-time X-ray dosimeter to study X-ray flux from the Sun at ground\'s level...

[a a]

new or used,
easily operated like a hand-held scanner

can emit sound

 

[Martin Brown]

On 05/09/2022 22:10, DecadentLinuxUserNumeroUno@decadence.org wrote:

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote in
news:tf5nlq$1740$1@gioia.aioe.org:

The only way to observe X-rays is from a very high altitude
balloon or a space vehicle there is far too much atmosphere above
us.

And it is not \"ordinary optics\" X-ray devices get foucused with
Aluminum lenses. Chandra cannot use Aluminized mirrors like other
optical spectrum devices do.

Glancing incidence focussing X-ray optics are comparatively new.
Chandra was ground breaking in terms of what it could do!

Before that it was coded mask apertures and fairly pathetic resolution.
It is still used in some regions of the spectrum and for neutrons.

https://www.sciencedirect.com/science/article/pii/S1350448716301524

--
Regards,
Martin Brown

 

[Phil Hobbs]

Martin Brown wrote:

On 05/09/2022 22:10, DecadentLinuxUserNumeroUno@decadence.org wrote:
Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote in
news:tf5nlq$1740$1@gioia.aioe.org:

The only way to observe X-rays is from a very high altitude
balloon or a space vehicle there is far too much atmosphere above
us.

   And it is not \"ordinary optics\"  X-ray devices get foucused with
Aluminum lenses.  Chandra cannot use Aluminized mirrors like other
optical spectrum devices do.

Glancing incidence focussing X-ray optics are comparatively new.
Chandra was ground breaking in terms of what it could do!

Before that it was coded mask apertures and fairly pathetic resolution.
It is still used in some regions of the spectrum and for neutrons.

https://www.sciencedirect.com/science/article/pii/S1350448716301524

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings. There\'s
virtually no refractive index contrast in the x-ray region, so he used
alternating layers of high and low loss (i.e. the contrast is in the
imaginary part of the index rather than the real part as usual.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Mike Monett VE3BTI]

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings. There\'s
virtually no refractive index contrast in the x-ray region, so he used
alternating layers of high and low loss (i.e. the contrast is in the
imaginary part of the index rather than the real part as usual.)

Cheers

Phil Hobbs

This sounds very powerful. Is it being used anywhere?

Would the alternating layers be sensitive to wavelength, making it
narrowband?



--
MRM

 

[Martin Brown]

On 06/09/2022 16:58, Mike Monett VE3BTI wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings. There\'s
virtually no refractive index contrast in the x-ray region, so he used
alternating layers of high and low loss (i.e. the contrast is in the
imaginary part of the index rather than the real part as usual.)

Impressive trick but did it ever find an application?

Cheers

Phil Hobbs

This sounds very powerful. Is it being used anywhere?

It sounds rather lossy to me. It might be handy in synchrotron radiation
sources - they are bright enough that you can afford to lose some.

Would the alternating layers be sensitive to wavelength, making it
narrowband?

Like any periodic structure you could presumably fine tune it.

That was how the original optical H-alpha filters were made with
appropriate thicknesses of quartz and calcite sandwiched together in a
stack that was then ovened to adjust the centre frequency.

You can do the same trick with crossed polarisers and selotape with
different thicknesses show in different colours.

Modern think film deposition etalons are way more stable and can operate
at room temperature merely by slightly tilting them.


--
Regards,
Martin Brown

 

[Phil Hobbs]

Mike Monett VE3BTI wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings. There\'s
virtually no refractive index contrast in the x-ray region, so he used
alternating layers of high and low loss (i.e. the contrast is in the
imaginary part of the index rather than the real part as usual.)

Cheers

Phil Hobbs

This sounds very powerful. Is it being used anywhere?

Would the alternating layers be sensitive to wavelength, making it
narrowband?

The lossy layers are very thin, so you can use a surprising number and
still get like 40% reflectance at normal incidence. As in any
interference coating, there\'s a three-way tradeoff between efficiency,
bandwidth, and number of layers (i.e. cost).

It was nearly 30 years ago, but iirc his mirrors got flown on some X-ray
telescope satellite.

The layers were (iirc) some metal and carbon.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Mike Monett VE3BTI]

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

It was nearly 30 years ago, but iirc his mirrors got flown on some X-ray
telescope satellite.

The layers were (iirc) some metal and carbon.

Cheers

Phil Hobbs

Thanks



--
MRM

 

[Mike Monett VE3BTI]

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

It sounds rather lossy to me. It might be handy in synchrotron radiation
sources - they are bright enough that you can afford to lose some.

Would the alternating layers be sensitive to wavelength, making it
narrowband?

Like any periodic structure you could presumably fine tune it.

That was how the original optical H-alpha filters were made with
appropriate thicknesses of quartz and calcite sandwiched together in a
stack that was then ovened to adjust the centre frequency.

You can do the same trick with crossed polarisers and selotape with
different thicknesses show in different colours.

Modern think film deposition etalons are way more stable and can operate
at room temperature merely by slightly tilting them.


--
Regards,
Martin Brown

Thanks



--
MRM

 

[server]

Mike Monett VE3BTI <spamme@not.com> wrote in
news:XnsAF0A79E158B9Bidtokenpost@88.198.57.247:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings.
There\'s virtually no refractive index contrast in the x-ray
region, so he used alternating layers of high and low loss (i.e.
the contrast is in the imaginary part of the index rather than
the real part as usual.)

Cheers

Phil Hobbs

This sounds very powerful. Is it being used anywhere?

Would the alternating layers be sensitive to wavelength, making it
narrowband?

Lead containment boxes are used for the old style monochrome X-ray
machines the airports used to use. They were 180kV firing into a
12mm Palladium chunk inside a $900 german made tube. (1998 dollars)

Our redesign was going to use brass encasement as it also stops X-
rays given enough cross sectional thickness, but ends up much lighter
in weight.

I wonder if a brass mirror would reflect. I doubt it. Not many
surfaces actually reflect X-rays. That is why incidence is used.

 

[server]

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote in
news:tf7vpk$1lan$1@gioia.aioe.org:

On 06/09/2022 16:58, Mike Monett VE3BTI wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

My old colleague Eberhard Spiller figured out how to make
normal-incidence X-ray mirrors using multilayer coatings.
There\'s virtually no refractive index contrast in the x-ray
region, so he used alternating layers of high and low loss (i.e.
the contrast is in the imaginary part of the index rather than
the real part as usual.)

Impressive trick but did it ever find an application?

Cheers

Phil Hobbs

This sounds very powerful. Is it being used anywhere?

It sounds rather lossy to me. It might be handy in synchrotron
radiation sources - they are bright enough that you can afford to
lose some.

Would the alternating layers be sensitive to wavelength, making
it narrowband?

Like any periodic structure you could presumably fine tune it.

That was how the original optical H-alpha filters were made with
appropriate thicknesses of quartz and calcite sandwiched together
in a stack that was then ovened to adjust the centre frequency.

You can do the same trick with crossed polarisers and selotape
with different thicknesses show in different colours.

Modern think film deposition etalons are way more stable and can
operate at room temperature merely by slightly tilting them.

I am not sure if there is any media that could be polished and
become a true reflector for X-rays.

Maybe some of the same elements that are used to generate them,
like Palladium.

 

[John Walliker]

On Monday, 5 September 2022 at 18:00:56 UTC+1, a a wrote:

new or used,
easily operated like a hand-held scanner

can emit sound

Its a nice idea, but I don\'t think a detectable X-ray flux will ever reach the ground.
Most of the X-rays emitted by solar flares - which obviously interest you - are low-energy
in the region of a few keV.
The atmosphere is a good absorber of X-rays.
From the following: https://chandra.harvard.edu/xray_astro/absorption.html
\"An X-ray photon passing through the atmosphere will encounter as many atoms as it would
in passing through a 5 meter (16 ft) thick wall of concrete! \"
This is why satellites are used for X-ray observation of the sun.

John

 

[a a]

On Monday, 5 September 2022 at 19:47:30 UTC+2, John Walliker wrote:

On Monday, 5 September 2022 at 18:00:56 UTC+1, a a wrote:
new or used,
easily operated like a hand-held scanner

can emit sound
Its a nice idea, but I don\'t think a detectable X-ray flux will ever reach the ground.
Most of the X-rays emitted by solar flares - which obviously interest you - are low-energy
in the region of a few keV.
The atmosphere is a good absorber of X-rays.
From the following: https://chandra.harvard.edu/xray_astro/absorption.html
\"An X-ray photon passing through the atmosphere will encounter as many atoms as it would
in passing through a 5 meter (16 ft) thick wall of concrete! \"
This is why satellites are used for X-ray observation of the sun.

John

thank you
I would like to study high energy X-class mass ejections
and build a live network of X-flux dosimeters world-wide, operated by peers,
just toi verify the above.

Directional dosimeters installed on solar trackers, shaded, protected against UV/IR,
transferring live, geolocated data to build X-ray flux maps on-the-go

---

The Sun and Solar Activity
Meaning of X-Ray Fluxes From the Sun

The solar X-ray flux arises from two factors. Firstly, there is flux coming from sunspot regions and other features - the background flux - and this varies slowly from day to day. Secondly, solar flares produce large amounts of X-ray flux, but this is concentrated to the duration of the flare which is usually from minutes to several hours.

Solar X-ray flux is described as follows:
Level Flux (watts/sq meter) Description
A less than 10-8 Very Low Background
A between 10-8 and 10-7 Low Background
B between 10-7 and 10-6 Moderate Background
C between 10-6 and 10-5 High Background/Low Flare
M between 10-5 and 10-4 Moderate Flare
X between 10-4 and 10-3 High Flare
Y greater than 10-3 Extreme Flare

Within these levels, a number is used to specify the flux. Hence a value M3..2 indicates that the flux is 3.2 × 10 -5 watts/metre2.

The Y classification of flares is new; and these extremely large flares are often still classed as X flares with a qualifying number greater than 10. Hence a Y1.6 flare is exactly the same as an X16 one.

Material prepared by Richard Thompson

from

https://www.sws.bom.gov.au/Educational/2/1/3


===
The Earth is constantly being bombarded by very energetic particles coming from the furthest reaches of our galaxy and even beyond. These cosmic rays have very different energies and can be created in a vast number of ways.

The majority of the cosmic rays we get on Earth come from the Sun, the explosion of stars (supernovae), pulsars and others remote galactic sources. When primary cosmic rays collide with the nuclei in the atmosphere, they give rise to a shower of secondary particles charged and neutrals. Among the charged particles are muons, unstable parents of the electron, able to long runs in the atmosphere. Secondary particles may reach the ground. In this way hundreds of these particles pass through our bodies every second, although the number increases with altitude. The further away you are from the Earth surface, the less effective the Earth\'s magnetic shield.

Effect of altitude
The rate of exposure to cosmic rays, represented here in microsieverts (millionths of a sievert) per hour, increases with altitude. For purposes of comparison, the average dose of natural radioactivity absorbed in one year is 2400 microsieverts.
IN2P3
The highest doses are therefore absorbed by astronauts in space flights, who may be exposed to an excess of 1 mSv per day. Plane flights at an altitude of 8,000 metres expose their passengers to a dose rate a hundred times greater than that felt at sea level, but only during a few hours : A passenger travelling from London to New York would only receive a dose of 0.032 mSv - the equivalent of a dental X-ray. The numbers being discussed are tiny, but the doses absorbed by frequent flyers and in-flight crew should be carefully monitored.

Secondary cosmic particles are not the product of radioactive decays. Nevertheless, they are the source of exposure to radiation when they reach the surface of the Earth. The flux of these cosmic particles is approximately 240 per metre squared per second at ground level. Many pass through our bodies every second.

In addition, 65 billion neutrinos pass through every square centimeter of our skin every second as if we were transparent. Neutrinos interact so little that among 100,000 billion solar neutrinos passing through the Earth, one or less than one less than one interacts or be stopped!

Without the Earth magnetic field, however, these fluxes would be far greater, as radiation levels double at 1,500 metres above sea level and increase still further the higher one goes. Even without getting on a plane we are still exposed to radiation which vary greatly from place to place. For the first few kilometres of the atmosphere, the exposure doubles approximately every 1,500 metres. Those living in the Andes or the Himalayas, therefore, are exposed to four times as much cosmic radiations as the inhabitants of Paris, London or New York.

The annual exposure to cosmic radiations at sea level is roughly 0.27 mSv, a figure which takes into account the protection offered by buildings. The average dose absorbed by an individual is extremely hard to calculate, given the large number of factors which are involved. In France, this figure has been calculated at around 0.30 mSv per year.

The constant shelling of the atmosphere also results in the production of small quantities of radioactive atoms. Carbon 14, for instance, is created when cosmic rays interact with atoms of nitrogen.

The huge telescopes in the Namibian desert
Cosmic gamma rays collide with the Earth day and night, but the elusive sparks of Cherenkov light they give off can only be observed on moonless nights far away from human habitation. This large telescope forms part of the HESS experiment, and is waiting for the sunset on the Namibian plains to start recording data. It is when the four telescopes simultaneously record the same spark that the cosmic gamma ray direction can be accurately determined..
HESS/LPNHE
The annual exposure to cosmic radiations at sea level is roughly 0.27 mSv, a figure which takes into account the protection offered by buildings. The average dose absorbed by an individual is extremely hard to calculate, given the large number of factors which are involved. In France, this figure has been calculated at around 0.30 mSv per year.

The constant shelling of the atmosphere also results in the production of small quantities of radioactive atoms. Carbon 14, for instance, is created when cosmic rays interact with atoms of nitrogen.
Very high energy cosmic particles
Very high energy particles coming from our galaxy and remote galaxies reach the Earth. They are studied by ground on the ground or onboard satellites experiments. When they hit the upper layers of the atmosphere, they generate cosmic showers. Although these showers do not have the size drawn by the artist, their detection requires ground devices occupying considerable area as in the case the HESS experiment. Même si ces gerbes n\'ont pas l\'ampleur de celle dessinée par l\'artiste, leur détection au sol nécessite des dispositifs occupant une surface considérable comme ceux de l\'expérience HESS.
Cosmic rays - 100 years of discovery
The study of cosmic rays and astroparticles

The origin of cosmic rays has been a major topic of research since their discovery by Victor Hess in 1912. The study of high-energy cosmic showers provides unvaluable information on the orgine of particles created in our galaxy or more distant galaxies, accelerated during the most violent phenomena in the Universe, sometimes reaching the Earth after a several billion years journey. Such is the purpose of Astroparticles, a new discipline of astronomy rapidly developing in recent years.

https://www.radioactivity.eu.com/site/pages/Dose_Cosmic.htm

=====so my interest is limited to
\\
https://www.radioactivity.eu.com/site/images/msv_altitude_En.jpg

Effect of altitude
The rate of exposure to cosmic rays, represented here in microsieverts (millionths of a sievert) per hour, increases with altitude. For purposes of comparison, the average dose of natural radioactivity absorbed in one year is 2400 microsieverts.
IN2P3

since at the ground\'s level/ sea level
exposure to cosmic rays is still at 0.03 microsieverts/hour

 

[John Walliker]

On Monday, 5 September 2022 at 19:29:09 UTC+1, a a wrote:

On Monday, 5 September 2022 at 19:47:30 UTC+2, John Walliker wrote:
On Monday, 5 September 2022 at 18:00:56 UTC+1, a a wrote:
new or used,
easily operated like a hand-held scanner

can emit sound
Its a nice idea, but I don\'t think a detectable X-ray flux will ever reach the ground.
Most of the X-rays emitted by solar flares - which obviously interest you - are low-energy
in the region of a few keV.
The atmosphere is a good absorber of X-rays.
From the following: https://chandra.harvard.edu/xray_astro/absorption.html
\"An X-ray photon passing through the atmosphere will encounter as many atoms as it would
in passing through a 5 meter (16 ft) thick wall of concrete! \"
This is why satellites are used for X-ray observation of the sun.

John
thank you
I would like to study high energy X-class mass ejections
and build a live network of X-flux dosimeters world-wide, operated by peers,
just toi verify the above.

Directional dosimeters installed on solar trackers, shaded, protected against UV/IR,
transferring live, geolocated data to build X-ray flux maps on-the-go

I think you may be underestimating the difficulty of the task. The only X-rays
that you could possibly detect are those with enough energy to pass through
about 16 feet of concrete, the equivalent of passing through the atmosphere.
They will have such a high energy that they will need a very
large detector to have a significant chance of interacting with that detector.
If you want the detector to be directional, then the problem gets harder. You
could, for example, make a collimator so that you only detect X-rays from one
particular direction. However, to block signals from other directions, you would
need a similarly thick layer of concrete or its equivalent. You could of course put
the very large detector at the bottom of a deep well and wait for the sun to pass
overhead, but that only works at the equator.
Another problem is that you would need to ensure there is no natural radioactivity
in the detector and the shielding around it that could give false positive results.

John

 

[Martin Brown]

On 05/09/2022 18:47, John Walliker wrote:

On Monday, 5 September 2022 at 18:00:56 UTC+1, a a wrote:
new or used,
easily operated like a hand-held scanner

can emit sound

Its a nice idea, but I don\'t think a detectable X-ray flux will ever reach the ground.
Most of the X-rays emitted by solar flares - which obviously interest you - are low-energy
in the region of a few keV.

And not especially penetrating so the amount of them you would see at
ground level would be well below any reasonable measurement threshold.
Even at very high altitude it is more the charged particles of the solar
that you worry about since they can do some damage.

You would be better off looking for mesons and at the top of a mountain
if you must try to do an independent check of satellite X-ray data.

Various sites show the results of the satellite observations and aurora
watch is a pretty good proxy for an active sun (although the charged
particles arrive somewhat later than the X-rays). eg

https://www.swpc.noaa.gov/products/goes-x-ray-flux

https://aurorawatch.lancs.ac.uk

If you wanted contemporaneous observational data then buy an H-alpha
narrow band solar imaging telescope which will allow you to watch the
prominences in real time. It is quite pretty and changes quickly. They
are not cheap but they are much cheaper than they used to be now.

http://www.ianmorison.com/h-alpha-solar-telescopes-an-in-depth-discussion-and-survey/

Looking at the sun through a telescope is a good way to end up blind.
You absolutely have to understand what you are doing here.

Around sunspot maximum and on polar routes aircraft sometimes got
diverted or asked to lose altitude because of solar activity. Not a
great risk to the passenger but because of the long term risk to the air
crew who do the same trip again and again.

The atmosphere is a good absorber of X-rays.
From the following: https://chandra.harvard.edu/xray_astro/absorption.html
\"An X-ray photon passing through the atmosphere will encounter as many atoms as it would
in passing through a 5 meter (16 ft) thick wall of concrete! \"
This is why satellites are used for X-ray observation of the sun.

John

The only way to observe X-rays is from a very high altitude balloon or a
space vehicle there is far too much atmosphere above us.

--
Regards,
Martin Brown

 

[server]

Martin Brown <\'\'\'newspam\'\'\'@nonad.co.uk> wrote in
news:tf5nlq$1740$1@gioia.aioe.org:

On 05/09/2022 18:47, John Walliker wrote:
On Monday, 5 September 2022 at 18:00:56 UTC+1, a a wrote:
new or used,
easily operated like a hand-held scanner

can emit sound

Its a nice idea, but I don\'t think a detectable X-ray flux will
ever reach the ground. Most of the X-rays emitted by solar flares
- which obviously interest you - are low-energy in the region of
a few keV.

And not especially penetrating so the amount of them you would see
at ground level would be well below any reasonable measurement
threshold. Even at very high altitude it is more the charged
particles of the solar that you worry about since they can do some
damage.

You would be better off looking for mesons and at the top of a
mountain if you must try to do an independent check of satellite
X-ray data.

Various sites show the results of the satellite observations and
aurora watch is a pretty good proxy for an active sun (although
the charged particles arrive somewhat later than the X-rays). eg

https://www.swpc.noaa.gov/products/goes-x-ray-flux

https://aurorawatch.lancs.ac.uk

If you wanted contemporaneous observational data then buy an
H-alpha narrow band solar imaging telescope which will allow you
to watch the prominences in real time. It is quite pretty and
changes quickly. They are not cheap but they are much cheaper than
they used to be now.

http://www.ianmorison.com/h-alpha-solar-telescopes-an-in-depth-disc
ussion-and-survey/

Looking at the sun through a telescope is a good way to end up
blind. You absolutely have to understand what you are doing here.

Around sunspot maximum and on polar routes aircraft sometimes got
diverted or asked to lose altitude because of solar activity. Not
a great risk to the passenger but because of the long term risk to
the air crew who do the same trip again and again.

The atmosphere is a good absorber of X-rays.
From the following:
https://chandra.harvard.edu/xray_astro/absorption.html
\"An X-ray photon passing through the atmosphere will encounter as
many atoms as it would in passing through a 5 meter (16 ft) thick
wall of concrete! \" This is why satellites are used for X-ray
observation of the sun.

John

The only way to observe X-rays is from a very high altitude
balloon or a space vehicle there is far too much atmosphere above
us.

And it is not \"ordinary optics\" X-ray devices get foucused with
Aluminum lenses. Chandra cannot use Aluminized mirrors like other
optical spectrum devices do.