Radiation protection

Terraformer · 2014-06-14 14:47:20

How much do we need? Assuming we have a magnetic field to deflect charged particles, how much mass do we need to attenuate gamma, UV etc to a safe level? Gamma seems to be unable to get past the first half a tonne of Terra's atmosphere... can we shield our colonies and ships with only half a tonne per square meter (with EM shielding), especially if we use optimal materials?

JoshNH4H · 2014-06-23 10:49:25

I think the biggest radiation issue is cosmic rays, which require either large/intense magnetic fields. Cosmic rays in interplanetary space are about 40 rem/year, while on a planet this gets cut down to 20 rem/year even ignoring any atmospheric shielding. I don't think gamma rays are the worst problem, necessarily, although unlike cosmic rays they do require physical shielding. The HVT for gamma rays is 1 cm of lead or 6 cm of concrete, according to Wikipedia.

Magnetic shielding can handle the charged particles well enough, but you'll need a pretty big magnetic field to handle it. If you're in a vacuum, you'd be able to use an M2P2, which if used at high power would probably be big enough to deflect the cosmic ray particles away from the craft at the center. If you're on a planet you'll probably need several meters of dirt as radiation shielding, of course remembering to make it thick enough that you capture the secondary radiation as well as the primary. I have a post on this somewhere, I'll see if I can dig it up.

JoshNH4H · 2014-06-23 10:52:46

Here it is!

I wrote:

By the way, I have access to the Curiosity paper through my university and I'd be glad to email it to you if you're interested. I believe you have my email?
One interesting table discussed the radiation under the surface. According to the paper, under 2 m of regolith the annual GCR dose will be 15 mSv, 1.5 Rem. While not trivial, this is well within acceptable limits. Although their models are more complex than this, I found the halving distance to be about .45 m for every meter past the peak radiation level at .1 m below the surface. Overall, for depths greater than 10 cm, a good approximation is:
R(D)=R_0*1.5*.5^(D/.45)
Where R(D) is the radiation that would be experienced by a person under D meters of shielding and R_0 is the radiation that they would experience with no shielding. Using the density estimate from the Curiosity paper (2800 kg/m^3), and assuming a habitat pressure of 500 mb, the depth of shielding would have to be 4.8 m. At this depth, the annual radiation dose for a person who remained inside would probably be about .2 mSv, or .02 Rem. Compared to .3 Rem per year on Earth, this is negligible.
However, this calculation is meaningless if the regolith used for shielding is itself radioactive.

Terraformer · 2014-06-23 11:24:14

So, it may be possible to use a magnetic field to shield Lunar colonies, combined with ~20cm of water?

What stops a magnetic field being used within an atmosphere?

It's good to know that my ship won't need to carry around really heavy shielding...

RobertDyck · 2014-06-23 11:44:34

A simple magnetic field can be used in an atmosphere. But a mini-magnetosphere is very thin plasma, charged plasma, held within the magnetic field. Anything moving that has charge will generate a magnetic field, so the plasma "inflates" the magnetic field. This extends it to a much greater size. Deflecting charged partics when they're farther away means the angle of deflection doesn't have to be as great to miss the spacecraft or habitat. However, a planetary atmosphere is thicker than the plasma used, and the atmosphere will neutralize the charge in a matter of seconds. So magnetic field works in an atmosphere, but not a magnetosphere.

JoshNH4H · 2014-06-23 12:32:42

^that. And in general it depends what the gamma ray environment is. I'd be looking more towards the structure of the ship for shielding rather than layers of water.

Terraformer · 2014-06-23 16:38:32

I remember something about building colonies in areas of natural magnetic fields. I wonder how large a field would have to be to protect a colony? Could we construct towers that project such fields to shield the colony?

I have layers of water in mind for planetary colonies, specifically low pressure garden areas. On ships, I would expect the hull to be thick enough (it does, after all, have to protect the ship in combat... ). But for a Lunar parkland? Perhaps it wouldn't be water, rather 20cm of plastic and glass. But water is cheaper, and if you don't need that much to contain the pressure, why not use water?

Then there's always the hope that Ceres has a magnetic field, which would make paraterraforming easier in that the shielding requirements would be much lower...

JoshNH4H · 2014-06-23 21:14:25

Well, pressure containment would actually require significantly more than 20 cm of water. Even on Earth, 20 cm of water would contain just 20 millibars of pressure. On the Moon, in 1/6 gravity, it would contain correspondingly less. To contain a 100 mb garden (50 mb CO2, 10 mb O2, 40 mb N2?) would require a meter of water, which I suppose isn't unreasonable, though of course it couldn't contain the pressure because it is not solid and would therefore presumably need something over it to contain its pressure (At 20 C, water boils at 24 mb).

Having said that, I do think this is a pretty good idea. It might be worth looking into the idea of densifying the water by adding in heavy metal salts, which would also offer increase protection from gamma rays.

Terraformer · 2014-06-24 04:44:27

Well, I wasn't thinking of using the mass to contain the pressure...

JoshNH4H · 2014-06-24 08:01:11

You wrote:

I remember something about building colonies in areas of natural magnetic fields. I wonder how large a field would have to be to protect a colony? Could we construct towers that project such fields to shield the colony?
I have layers of water in mind for planetary colonies, specifically low pressure garden areas. On ships, I would expect the hull to be thick enough (it does, after all, have to protect the ship in combat... ). But for a Lunar parkland? Perhaps it wouldn't be water, rather 20cm of plastic and glass. But water is cheaper, and if you don't need that much to contain the pressure, why not use water?
Then there's always the hope that Ceres has a magnetic field, which would make paraterraforming easier in that the shielding requirements would be much lower...

Emphasis mine, obviously.

Terraformer · 2014-06-24 08:48:47

Ambiguous phrasing. I was talking about plastic, in the sense of the required thickness to contain 1-200mb of pressure.

JoshNH4H · 2014-06-24 09:33:06

Ah, my mistake. The interesting thing about water is that if you use a dome shape it gets significantly more difficult to contain the pressure at the bottom as compared to the top.

Rusakov · 2014-09-16 20:48:58

Wasn't there research done that berries can counteract the effects of radiation? Maybe that could cut down on the shielding needed.

tahanson43206 · 2020-12-22 10:15:43

The link below was originally posted by a member who went by: akwx128 - Essentials

https://newatlas.com/demron-lightweight … suit/9300/

The link still works, and the content still appears relevant.

If someone in the active membership has an interest in this garment material, I'd appreciate an update. the original goes back to 2002 or so.

(th)

SpaceNut · 2020-12-22 13:45:30

That member seems to have started posting in 2008, just one topic with regards to how one would live in a small section of any structure.
Of course there are different levels of radiation along the trip to and on mars. While mars gives minimal protection to what would be the levels of open space its not much until we get beneath a layer design to protect us from the radiation which comes in many wavelengths that are harmful with specific condition to eat for detection and block.
Its suggested that during the journey let the food stores and water do the job but on mars we need to do more in that it takes moving tons of regolith soil to create that barrier to which we need.

SpaceNut · 2020-12-22 14:44:24

tahanson43206 wrote:

Regarding the link to the article about a fabric designed to help with radiation shielding .... the article is not about using materials in a space craft to assist with shielding ... the article is about a fabric that takes the place of lead sheets formerly worn by medical technicians when performing X-Rays.
The new material (taking into account that the post goes back several years) is apparently able to stop charged radiation the way lead does, by providing a greater number of electrons to intercept positively charged particles than are available in ordinary clothing.
(th)

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

Xrays are just a small wavelength of the radiation electromagnetic spectrum in which we would do the simple clothing or apron trick but we will need more.

What spectrum is used around us

https://imagine.gsfc.nasa.gov/science/t … trum1.html

SpaceNut · 2020-12-28 21:23:17

NASA is testing a space radiation protection vest aboard the International Space Station that could shield astronauts from deadly solar flares on missions to the moon and Mars.

The new vest is designed with flexible polyethylene shapes to fit men or women and protect their most vulnerable organs.
"We are trying to see if astronauts can wear it as long as possible, without experiencing pain or discomfort,"
"Several astronauts will wear the vest, with eight hours as the longest period, while sleeping,"

Makes sense....

The vest provides targeted protection for the pelvis - where large amounts of bone marrow can absorb radiation - and other organs such as the lungs, breasts and ovaries,
"Trying to protect the entire body means adding a lot of weight," he said. "You can protect in a reasonable way, a fraction of your body, or a part of your body that happens to be the more sensitive part."
"The AstroRad shields astronauts from space-borne ionizing radiation in an efficient way, provides operational simplification, and allows for the use of recycled material on-board the vehicle,"

The moon it may not be enough but for mars conditions it may just be enough....

Void · 2022-11-21 22:09:06

I stumbled across this today "Selenomalanin".

It dates from about Aug-2020, and I don't see any follow-up. Hope it is not a falsehood.

General Search: https://www.bing.com/search?q=Selenomal … 83211d8479

This is where I saw it. As I have said, I have some concerns that it is not an actual thing, but here is the video: https://www.youtube.com/watch?v=I50EEKzrOd4

So, could there be a color "X-Ray"? If so, then maybe............???

Done.

Last edited by Void (2022-11-21 22:15:48)

Calliban · 2022-11-22 00:10:21

Void, interesting find. I will read about it after work.

Some time ago, I looked into what effect Mars surface radiation would have on human life expectancy. I assumed a 50-year career exposure, for 2000 hours per year (40h/week), with most time spent at low Martian lattitudes. The loss of life expectancy worked out to be about the same as air pollution for the average human being living on Earth. Given that Martian settlements will be free from air pollution and largely underground (to conserve heat, as well as provide radiation protection), I felt satisfied that Mars surface radiation would not present a catastrophic health impact for a Martian population, even if they spend their entire working lives out on the surface.

In space, or on the moon, it may be a different story. Whilst the Martian atmosphere is thin by Earth standards, it reduces cosmic ray absorbed dose by half compared to the lunar surface. At low lattitudes, it blocks entirely the most dangerous heavy particle radiation. Most of the cosmic ray flux at ground level in the Martian northern plains is protons, with a RBE of 1.1. Heavy ion radiation with Z up to 56, has RBE of 50 or more. Even though particle flux is only a small proportion of total cosmic ray flux, heavy ions make up a significant proportion of total dose in free space. The Martian atmosphere is thick enough to shield out most heavy ion radiation.

Last edited by Calliban (2022-11-22 00:30:09)

tahanson43206 · 2022-12-18 07:41:22

https://www.digitaltrends.com/space/nas … t-artemis/

Digital Trends
How will NASA keep Mars astronauts safe from cosmic radiation? Here’s the plan
Story by Georgina Torbet • Yesterday 12:05 PM
The Artemis I mission, which recently completed a historic test flight around the moon, didn’t have any astronauts on board — but it did have two very special passengers: Helga and Zohar, a pair of highly anatomically detailed dummy torsos, one of which wore a special radiation shielding vest for the journey. Their mission? Measure radiation exposure in deep space and determine whether a vest can help protect astronauts from the unseen dangers of space.
To learn more about the threat of space radiation and how to protect astronauts against it, we spoke to the CEO of the company that makes the vest, StemRad, as well as to retired NASA astronaut Scott Kelly, a veteran of space station missions who is well known for his role in research into astronaut health.
The unseen dangers of radiation
Here on Earth, we’re protected from dangerous radiation by the planet’s magnetosphere. The magnetic field around Earth traps radiation into two areas called the Van Allen belts, making it safe for us on the surface. But when astronauts go beyond low Earth orbit, as they must to visit the moon (and other potential locations in the solar system, like Mars), they are exposed to dangerous radiation.
An aurora as seen from the space station.
© Provided by Digital Trends
In the long term, exposure to this radiation — which consists of charged particles from the sun called solar winds, particles ejected in coronal mass ejections, and cosmic rays — can lead to a variety of health problems. Most significantly, radiation exposure raises the likelihood that someone will develop cancer or various degenerative diseases. That’s why NASA and other space agencies have a cap on how much radiation an astronaut can be exposed to over their lifetime.
Continue reading
That’s where the AstroRad vest comes in. Made from a hydrogen-rich polymer material, the vest covers the pelvis and torso, protecting the most vulnerable organs from solar radiation. It might seem surprising that radiation protection could be applied to only certain parts of the body, and StemRad CEO Oren Milstein said many of those in the space industry he pitched the idea to were surprised too. But full-body protection would be incredibly cumbersome, and the best protection would be something that astronauts could actually wear and still do their jobs.
Visit site to see more if interested ...

(th)

Mars_B4_Moon · 2023-03-10 14:56:37

So I came across one of those high energy galactic event stories, cosmology and explosions

'Galactic Explosion Reveals New Details About the Universe'
https://scitechdaily.com/galactic-explo … -universe/

and it go me thinking again, Mars might not be about shielding humans but it might be necessary to shield your entire crop or only have crops and animals that are hardy and able enough for an extreme event. If Mars and other places like the Moon develop levels of self-sufficiency, growing their own crops inside a biosphere that is great for the colony. However what happens with extreme events CMEs, Cosmic-Rays, Near By Supernova explosion. The odds of it happening are small but perhaps not insignificant, we have probably seen these events in human history, Danish astronomer Tycho Brahe's Supernova, Chinese ‘guest star’ of 392 AD, Supernova 3C58 by Japanese and Chinese astronomers as a guest star, Kepler's Supernova seen during the daytime, SN 1006 Supernova recorded in rock art, Crab Nebula recorded by many cultures.

Many ideas have been discussed for Mars including making a magnetic shield or having a Dome that is monitored by robots and satellite and can raise shielding, a plasma bubble, atmospheric shielding at Mars provides far more protection. If there is a sudden drop in wheat production or large scale 'crop failure' inside the Lunar biosphere the Moon is closer to Earth for rescue and delivery of aid, and on the Moon we discussed ideas for the lunar electrostatic shield. On the ISS plants seem to be hardy enough to grow normally, the Gateway might show different results and Radiation on the surface of Mars is half that of ISS, I'm not sure what height the Chinese station is but I believe it orbits higher than ISS and plants also grow healthy, fine and hardy there.

Types and sources of radiation
https://nuclearsafety.gc.ca/eng/resourc … -radiation

Exposure from cosmic radiation
The earth's outer atmosphere is continually bombarded by cosmic radiation. Usually, cosmic radiation consists of fast moving particles that exist in space and originate from a variety of sources, including the sun and other celestial events in the universe. Cosmic rays are mostly protons, but can be other particles or wave energy. Some ionizing radiation penetrates the earth's atmosphere and becomes absorbed by humans, which results in natural radiation exposure.
The doses due to natural sources of radiation vary depending on location and habits. Regions at higher altitudes receive more cosmic radiation.

The cosmological parsec symbol pc, is about 3.26 light-years. An estimated 20 supernova explosions have happened within 300 pc of the Earth-Sol system over the last 11 million years, they can have have noticeable effects on Earth's biosphere with records lasting in our Paleontology history. Type II supernova explosions are expected to occur in active star-forming regions. there are six near-Earth supernova candidates within 300 pc. Was life damaged by Vela Supernova Remnant 800 ly, 12,000 years ago and Geminga 550 ly 300,000 years ago? Betelgeuse, Alpha Orion or α Ori, is about 430 light-years away or 131 point 9 light years. Some people even blame one of our Ancient pre-Dinosaur extinctions Late Ordovician mass extinction on a possibly near by Gamma Burst or Supernova, killing 85% of all species, nearly 80 + % of all marine species killed off.

Time outside in the spacesuit working or mining or 'exploring' would be limited to some limited number of hours per week. Gamma X-rays and Neutrons are tougher challenge to protect against but the Planet Mars offers far greater protection than our Moon. Where necessary in a far future some Hardy A.I Robot or Cyborg Creature might be able to fill the role of the mundane but risky task a human was expected to do, the Sun will perhaps be highly monitored by fleets of satellites as most radiation events will be coming from our Sun, even on our Earth Australia when talk about the Ozone Layer was popular Australia tv used to give weather reports about UV radiation and sun protection times.

tahanson43206 · 2023-07-06 06:58:20

Recent discussions in battery related topics turned up a material that may be useful for capturing some radiation in free space..

BNNT — the game-changing nano material
What is BNNT?
Boron Nitride Nanotubes (BNNTs) are an advanced nanomaterial with unique physical properties. NASA has identified it as a key nanomaterial that may even help humans reach Mars, due to its strength and radiation absorption properties. We take advantage of its physical strength, thermal conductivity and electrical resistance as well as some unique electrochemical properties to enhance our lithium sulfur and lithium metal batteries

Above is from the web site: https://www.lis.energy/technology/

(th)

Mars_B4_Moon · 2023-12-29 06:41:09

If it happens....Bright enough to see during the daytime

Will Betelgeuse be going supernova soon after all?
https://timesofmalta.com/articles/view/ … ll.1070622
It found that Betelgeuse might actually be at a late stage of its carbon fusion phase

'Estimated Radiation Dosage on Mars '
https://www.jpl.nasa.gov/images/pia0348 … ge-on-mars

Last edited by Mars_B4_Moon (2023-12-29 06:43:08)

Mars_B4_Moon · 2024-05-15 12:33:21

Red Aurora over Poland
https://apod.nasa.gov/apod/ap240512.html
Northern lights don't usually reach this far south. Magnetic chaos in the Sun's huge Active Region 3664, however, produced a surface explosion that sent a burst of electrons, protons, and more massive, charged nuclei into the Solar System. A few days later, that coronal mass ejection (CME) impacted the Earth and triggered auroras that are being reported unusually far from our planet's north and south poles.

Mars_B4_Moon · 2024-05-25 07:26:15

NASA selects instrument for solar study on ESA mission

https://www.spacedaily.com/reports/NASA … n_999.html

New Mars Forums

Announcement

#1 2014-06-14 14:47:20

Radiation protection

#2 2014-06-23 10:49:25

Re: Radiation protection

#3 2014-06-23 10:52:46

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#4 2014-06-23 11:24:14

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#5 2014-06-23 11:44:34

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#6 2014-06-23 12:32:42

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#8 2014-06-23 21:14:25

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#14 2020-12-22 10:15:43

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#15 2020-12-22 13:45:30

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#17 2020-12-28 21:23:17

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#21 2023-03-10 14:56:37

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