New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#51 2022-03-05 08:21:09

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

SpaceNut ... as suggested earlier in this topic, your initiative to develop a dynamic radiation protection system for ships of the Large Ship (Prime) class has the potential to serve a wide range of customers who need a level of protection greater than a simple water wall.

Your suggestion of  mounting a set of Starships in a girder system makes perfect sense to me.  The Starships selected for this arrangement would (of course) be the ones adapted for a flight to Mars on their own. 

Your offer would provide artificial gravity and radiation protection, as well as safety in numbers for a flotilla of Starships.

Please continue to develop your ideas by building real-Universe demonstration models so we can get away from vapor theory.

We need actual performance readings reported in this topic, for various arrangements of hardware.

(th)

Offline

#52 2022-03-05 08:36:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

Searching for materials to build a model with features of structure, radiation and more so that we could show off what we are designing for sure.

Offline

#53 2022-03-25 15:03:50

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

The article at the link below is about more than radiation, but enough of the substance is about radiation that I decided to put it here...

https://www.msn.com/en-us/news/technolo … hp&pc=U531

In an interview with Futurism's Jolene Creighton, Neil deGrasse Tyson said rather than colonizing Mars, we should aim for "just an outpost." Tyson went on to describe the highly unlikely possibility that humanity would be able to develop the necessary "entire infrastructure in which you live that mimics Earth."

"We'd rather stay where it is warm and comfortable," said Tyson. While Tyson is not optimistic about humans establishing a large footprint on Mars, his position stands in sharp contrast to Elon Musk, CEO of SpaceX. Despite his assertions about early explorers needing to prepare for the worst, Musk continues to dare to dream that we might reach Mars soon and is getting the SpaceX Starship ready for the journey.

According to NPR, Musk is targeting 2029 as the timeframe for landing the first humans on Mars with cargo missions sent in advance to give astronauts the resources and materials they will need to set up an initial base. No doubt, we will all be watching in awe as this unfolds and wonder who will ultimately be right about the future Mars holds for human civilization: Neil deGrasse Tyson or Elon Musk?

The headline writer sensationalized the sentiment of Dr. Tyson, to grab attention.   I do not read his remarks as "never", but instead, guardedly skeptical.  The observations about radiation seem worth reviewing.  There are some humans alive today who do not take the risk seriously.  I consider that to be largely because the question is academic for most. 

(th)

Offline

#54 2022-03-26 12:26:45

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

We know what to do once on mars surface to reduce levels its in open space that we must do something....

Offline

#55 2022-03-30 14:21:54

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

For SpaceNut ... if you can squeeze in a bit more time during the week ahead, please take another look at this topic.

From my perspective, while we've accumulated quite a bit of useful information, we have not arrived at a prescription to apply to the Large Ship case.

We need to move out of theory and into practical demonstration as soon as possible.

That doesn't mean members of this forum necessarily have to do the demonstrations, although that would be ideal.

If others (anywhere on Earth) are doing the physical demonstrations, news of their experiments and the results they obtained would be welcome.

The objective capability I have in mind is deflecting galactic radiation, up to and including totally de-ionized iron nuclei.

(th)

Offline

#56 2022-04-02 13:01:04

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

For SpaceNut ...

Since you are the only member of the NewMars team working on Radiation Protection...

Here is an update on electrons (as distinct from positively charged particles)...

https://www.yahoo.com/entertainment/res … 00194.html

Researchers solved the mystery of super-fast ‘electron rain’ that pours down on Earth
Joshua Hawkins
Fri, April 1, 2022, 9:40 PM

If you purchase an independently reviewed product or service through a link on our website, BGR may receive an affiliate commission.

Scientists at UCLA have uncovered a new source of super-fast electrons that rain down on the Earth. When interacting with the Earth’s atmosphere, these electrons create beautiful phenomena like the Northern Lights. However, scientists say they also pose a significant threat to spacecraft, satellites, and astronauts. The scientists combined data captured by UCLA’s ELFIN satellites and NASA’s THEMIS spacecraft to study the new “electron rain”.

Discovering the source of the ‘electron rain’
northern lights photo

The researchers say they observed the unexpected electron precipitation from a low-Earth orbit using UCLA’s ELFIN satellites. These satellites are part of the ELFIN mission and include two satellites the size of bread loaves. They published their findings in the journal Nature Communications this month.

After discovering the electron rain, they also looked at data from NASA’s THEMIS spacecraft. This allowed them to get a broader look at the effects of the raining electrons using distant observations. By doing this, the team was able to determine that Whistler Waves are behind the electron precipitation.

See, electrons typically travel between the Earth’s north and south poles within what we call the Van Allen radiation belts. These belts are a key part of the events that take place within the near-Earth space environment. However, when Whistler Waves are generated within the radiation belts, the electrons grow more energized and speed up.

When they start to move faster and gain more energy, the electrons are more likely to fall through the belts and into the atmosphere, creating electron rain.

Why scientists are worried about Whistler Waves
Earth magnetic field with solar flare could cause electron rain
Earth magnetic field with solar flare could cause electron rain
So, a few extra electrons make it into the atmosphere and possibly make more aurora borealis. That isn’t that big of a deal, right? Well, the researchers say it could prove hazardous to satellites, spacecraft, and even astronauts.

That’s because whenever solar flares cause geomagnetic storms that affect our near-Earth space, they also affect the Earth’s magnetic environment. In the past, we’ve seen reports of solar storms causing lost sea mines to explode due to the intensity of the energy that hit the Earth at the time.

When these storms happen, electron rain is even more likely as electrons fall from the radiation belts that surround our planet. Current models and theories for space weather don’t typically account for this kind of electron precipitation. This is why it’s so important for us to study it now.

Scientists say that Whistler Waves can have a massive effect on the Earth’s atmospheric chemistry. And, if that was to happen while a spacecraft or satellite was passing through a low-Earth area, then it could pose risks we haven’t previously accounted for.

The discovery of this electron rain is also a huge indicator of just how connected space and the Earth’s upper atmosphere is. It’s also a great reminder of just how important understanding those elements can be to providing safe travel for astronauts and spacecraft passing through the atmosphere in the future.

Click here to read the full article.

See the original version of this article on BGR.com

(th)

Offline

#57 2022-04-02 14:03:51

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,361

Re: Large Ship Radiation Protection

Since so much of the radiation encountered in both the Van Allen Belts and deep space is high energy ions and electrons, I think the following publication is of interest to this discussion:

Calculation of water equivalent thickness of materials of arbitrary density, elemental composition and thickness in proton beam irradiation

From the publication:

Abstract:

In proton therapy, the radiological thickness of a material is commonly expressed in terms of water equivalent thickness (WET) or water equivalent ratio (WER). However, the WET calculations required either iterative numerical methods or approximate methods of unknown accuracy. The objective of this study was to develop a simple deterministic formula to calculate WET values with an accuracy of 1 mm for materials commonly used in proton radiation therapy. Several alternative formulas were derived in which the energy loss was calculated based on the Bragg–Kleeman rule (BK), the Bethe–Bloch equation (BB) or an empirical version of the Bethe–Bloch equation (EBB). Alternative approaches were developed for targets that were ‘radiologically thin’ or ‘thick’. The accuracy of these methods was assessed by comparison to values from an iterative numerical method that utilized evaluated stopping power tables. In addition, we also tested the approximate formula given in the International Atomic Energy Agency's dosimetry code of practice (Technical Report Series No 398, 2000, IAEA, Vienna) and stopping power ratio approximation. The results of these comparisons revealed that most methods were accurate for cases involving thin or low-Z targets. However, only the thick-target formulas provided accurate WET values for targets that were radiologically thick and contained high-Z material.

Scroll down through the document to "Table 2" (most of the way down the page) to see what it takes to stop a 100MeV proton beam:

At proton energies of 100MeV, it takes 1.5cm of Lead, more than 1.5cm of Aluminum, or 10cm of PMMA plastic.

Lead: 11.35g/cm^3; Aluminum: 2.7g/cm^3; PMMA 1.2G/cm^3

In this test, Lead Shielding 17.025g/cm^2 stopped 100MeV protons; 4.05g/cm^2 failed to stop them; 12g/cm^2 stopped them

If you scroll further down the table, you will see that PMMA was the most effective at stopping higher energy protons, and stopped them proton beam cold at energies of up to 120MeV, where even 17.025g/cm^2 of Lead failed to stop the beam.

Notice that the WER for PMMA is the lowest for higher energy protons, whereas Lead is the highest, meaning the ratio of the material required to stop high energy protons, in comparison to water (1g/cm^3), is lowest for the lowest density Hydrogen-rich materials such as plastics or synthetic fabrics or water.  Water obviously cannot serve as a structural material, but it represents the lowest practical mass for stopping higher energy protons through elastic collisions that sap the incoming high energy particles of their extreme energy levels.  I read somewhere, a NASA website I think, that 400mm of Lead would be insufficient to stop a proton at 400MeV energy levels.

We don't have data on whether or not another Carrington-type event would produce greater than 400MeV energy levels in Earth's Van Allen Belts, but we do know that the highest proton energy levels range between 100MeV and 400MeV during "normal" activity.  We also know that at the most extreme energy concentration within the Van Allen Belts, that the radiation dose is 0.05 rads per second.  There are 86,400 seconds per day, so if you spent a full day in one of these regions with no protection then the received does would be 4,320rads.  LD50 is considered to be 300rads per hour.  We would obviously want to stay far far away from ever approaching that kind of radiation level.  The proton fluences can be chaotic and highly localized, but we can see from testing that 10cm of water stops 100MeV protons cold, and that's most of the radiation encountered.

It should be noted that the proton itself may not be what does the damage, but the secondary interactions with the matter that the proton strikes, which can include secondary neutrons from striking certain materials, Coulomb collisions, and gamma ray emission.  The loss of energy from elastic collision and gamma ray emission issue is why stopping these energetic protons with low-Z materials is so desirable.

We can use this document from NIST as a guide:

Penetration of Proton Beams Through Water I. Depth-dose Distribution, Spectra and LET Distribution

This document is more concerned with precise proton radiation control required by proton therapy shielding applications:

Proton Mass Electronic Stopping Power

I especially liked the following quote:

The range of protons in water can be controlled to within 1 millimeter from 4 cm to 32 cm using range shifting plates. (Note to Physicists: Patients are not water tanks.)

Offline

#58 2022-04-02 20:12:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

Kbd512 the shadow wall was all that RobertDyck has planned for as it circles earth and is not crossing the belts that would be all we would need unless we are looping to get near to escape velocity. If we are that changes the game for exposure.

Offline

#59 2022-04-03 11:22:03

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,361

Re: Large Ship Radiation Protection

SpaceNut,

This is intended for my ship design, not RobertDyck's ship design.

Offline

#60 2022-04-03 11:47:21

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

For kbd512...

Since I created this topic, I am managing the topic.

I was surprised by your post to SpaceNut, so I went back to read Post #1 of this topic.

it was NOT my intention to limit the topic to one version of Large Ship, so I will go back to update Post #1 to be sure that your design is covered as well as Large Ship (Prime).

Thanks for providing the opportunity for me to improve the wording of Post #1.

For all re any topics I am managing ... please do not hesitate to provide feedback on the wording of Post #1 of any topic.  If something I have written is not clear, or is otherwise not helpful, please let me know.

The idea I have in mind for any topic is to provide a focal point for a specific field or activity.

(th)

Offline

#61 2022-04-03 13:48:44

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,361

Re: Large Ship Radiation Protection

tahanson43206,

I haven't posted much because I'm reading about electric propulsion to figure out what's practical and what's actually been done.  It's my belief, based upon research, that it's practical to spiral out, to adequately protect the ship's crew from the Van Allent Belt radiation during the spiral, and to complete the spiral out within a reasonable timeframe.

Offline

#62 2022-04-03 18:44:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

It sure would be practical to protect the crew for a spiral out that crosses and the design was started with permanent magnets as the field core needs a path to form and that pattern is a mesh that encircles the ships hull. From there the coils are wrapped around this core with temperature shield to help keep them cooler as they are pulsed and since each coil is independent the phasing will step through each spinning to seep the radiation around the ship. The holder that keeps the coils and grid combination acts an antenna to allow for RF to be sent outward as well.

Offline

#63 2022-04-04 06:24:11

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

While protecting against radiation near Earth, and against Solar flares covers a major part of the need, I'm trying to encourage those working on radiation protection to shoot high enough to protect against cosmic radiation.

If the group achieves protection against cosmic radiation, then the other dangers will have been folded in as well.

No passive solution to ** that ** problem appears to be practical for a ship that must use every gram effectively.  A passive solution would appear to be practical for a space station that is built in orbit and stays there.

The solution is (it seems to me) most likely to come from the use of dynamic energy flows (eg, current flowing in wires).

Hand waving is not going to yield an effective radiation shield.

Pulling reports from the written record may help, but by itself, that information does not yield a radiation protection system.

At some point, Real Universe demonstration of radiation protection **must** occur.

(th)

Offline

#64 2022-04-04 18:53:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

Seems that the belts are moved by VLF which is the 10k to 30k band of frequencies or audio level signals.

Cosmic radiation are stopped by the materials which have high hydrogen content, BNNT and a few others just fine.

Found this topic that goes with some of the discussion and there are most likely many other posts which cover the area as well.
Space Radiation + counter measures

Offline

#65 2022-04-14 08:19:45

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,423
Website

Re: Large Ship Radiation Protection

From 4-14-22 “Daily Launch”

Sunspot Launches Ball Of Plasma Toward Earth

The Daily Mail (UK) (4/13) reports that the sunspot R2987, previously thought to be inactive, “launched a fiery ball of plasma towards the Earth, and it will act to trigger more intense northern lights as it collides with the planet tomorrow.” Space weather forecasters “say it released an energetic burst of radiation, creating a coronal mass ejection (CME) that is expected to hit the Earth, with charged particles colliding with the planet’s magnetic field,” on Thursday.

This is the short-duration,  high-intensity radiation threat composed of particles far less energetic than cosmic radiation.  The worst of these known so far are like the 1972 event,  which would expose you to 10^3 to 10^4 REM over a matter of several hours.  That's orders of magnitude above the lethal dose:  300 REM in a short time for LD50,  and 500 REM in a short time is LD100. 

This is the stuff that 15 cm of water shields rather effectively.  The same shield lowers cosmic radiation a few percent,  without secondary shower effects because all the atoms in it are low atomic weight.

In comparison,  the exposure estimates for cosmic radiation vary sinusoidally with solar cycle,  from 60 REM per YEAR(!!!) at solar min,  to 24 REM per year at solar max.  This is not the lethal stuff,  this is the ~3% greater risk of cancer late in life risk.  All the yammer about cosmic rays being a barrier to deep space spaceflight is BS.  It is the solar flare events that are the lethal risk. 

The astronaut exposure standards are max 50 REM in a year,  no more than 25 REM in any one month,  and an age and gender-dependent career limit that maxes out at 400 REM lifetime.

Those solar flare events are intense,  brief (several hours),  occur very irregularly,  intensity varies drastically (from 10 to 10^4 REM in those hours),  and they are very directional.  THAT is what you really need shielding for!  Just don't use metals for it,  because you will get the secondary shower effects from cosmic radiation hitting it,  and those effects can be lethal.

This was known at the time of Apollo,  but ignored,  since the missions were only 2 weeks long at most.  The odds were that no event would hit a mission in space.  Yet the worst event we ever saw occurred between two Apollo missions to the moon in 1972!  Shows how inadequate that approach was!

GW

Last edited by GW Johnson (2022-04-14 08:24:47)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

Offline

#66 2022-04-14 09:01:28

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: Large Ship Radiation Protection

One way of effectively shielding solar particles and reducing cosmic ray dose, would be cluster sleeping arrangements into cubby hole tubes and arrange the ship's food supply, water and waste tanks around that single compartment.  During solar storms, you just stay in your bunks.  In such a compact arrangement, even human bodies will provide a sort of collective shielding.  There should be enough shielding to screen out cosmic rays for the 8 hours out of 24 that people are sleeping.  That would reduce cosmic ray dose by one third.

Last edited by Calliban (2022-04-14 09:05:35)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

Offline

#67 2022-04-14 20:33:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: Large Ship Radiation Protection

The large ship currently has water on the sun facing surface area for this purpose and couple that with more water for balancing and human waste systems means we have quite a thick natural radiation protection system.

Offline

#68 2022-08-09 07:57:45

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

It's been since April when the last post was added to this topic ...

To refresh:

tahanson43206 wrote:

For Calliban .... this post is a continuation of free association inspired by #27

Electrostatic force is notable for having a center, or at least the possibility of a center.

This reminds me .. it is wildly off topic, and it belongs in the radiation topic, but the current discussion reminded me of a need for research to see if a capacitor can deal with ionized radiation.

It is known for decades (see Keppenheimer, et al) that electrostatic force can ward off charged ions, including Cosmic alpha particles travelling near the speed of light.  The disadvantage (also known for decades) is that a radiation system designed with just one charge (ie, positive) on the outside (as of a sphere) would deflect positively charged particles but accelerate negatively charged ones.

So my question for research in space is ... If a capacitor plate of (let's say) one square meter in cross section is set parallel to another plate of the same dimension, and a charge is induced between the two, would the positive side deflect positively charged particles, and would the negatively charged back plate repel negatively charged ones?

This topic is about propane as an energy carrier (I remind myself)

We are off on this tangent because the possible use of fusion to make propane entered the  topic in a perfectly legitimate addition.

I'm right in the middle of debugging the Email Outreach script, and took a quick break to check the forum.

Hopefully later I'll return to put this side track into a more appropriate topic.

(th)

edit to put back in content

SpaceNut wrote:

tahanson43206, 2 plates with separation with media between it is electrolysis the moment you pass a current between the plates.

We know that co2 passed in a chamber with the moxie membranes would allow for oxygen to be vented with co to be made use of in the seawater process. But is there a means to use heat to break the water bond and use of a membrane to do the same without power?
I think void brought forth a titanium oxide plate, but I am having a memory gap.

edit
Seems that high temperature above 2000' c while it will cause the water to break down its the ignition of hydrogen and oxygen that soon happens. That mean you need higher temperature membranes and power to force the hydrogen towards a plate while the oxygen would go towards the other.
Seems the much lower temperature of just 500'c mean you get a lower efficiency for reaction as the 100'c for boiling is just the starting point for the bond to begin to break.
https://www.scienceforums.net/topic/113 … -pressure/

Offline

#69 2022-08-09 08:10:19

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

A test of the capacitor radiation protection idea would be possible in space at modest expense.

The protection ** should ** be able to withstand the massive solar flare eruption that GW Johnson described in a post earlier in this topic.

The history of the idea goes back to the earliest years of the New Space movement, and it is documented by TA Heppenheimer (et al).

Today, I'm renewing a call for development of a test model, using solar panels on the Sun facing side to collect energy to pull electrons from the center panel, and apply them to the panel furthest from the Sun.

The resulting configuration, when powered up, will (should) be able to deflect positively charged ions at the first panel, and negatively charged ones at the second panel.

Both types of ions should collect on the  panel to some extent.

This is a relatively inexpensive dynamic radiation protection idea, and I would like to see it move forward.

The entire NASA Gateway could be given radiation protection by a shield of this type, positioned between the Gateway and the Sun.

It would most definitely be possible to make an image of what this system would look like, using Blender or Fusion 360.

I'll try to arrange time to produce such an image.

I could use assistance thinking through how to design electronics to receive power from the solar panels, to pull electrons from the near plate and deliver them to the far plate.   I ** think ** that a Direct Current power supply is needed, able to produce extremely high voltages by using alternating current as an intermediate stage.  The electronics used to power a Tesla Coil may be a good match for the requirement.

The capacitor plates will be operating in space, so the vacuum of space will provide the greater part of the non-conductive volume needed for the applicaiton.

(th)

Offline

#70 2022-08-09 08:58:57

Void
Member
Registered: 2011-12-29
Posts: 6,975

Re: Large Ship Radiation Protection

I haven't seen enough of the plan to understand it, but vacuum is typically "A greater partial vacuum".  Or a degree of vacuum.

Vacuum conducts electricity.  I am not disputing the device and if it can work, rather I am pointing out that vacuum, which is not in our experience perfect, does conduct electricity.  That is why vacuum tubes worked.

Just a minor point, it does not invalidate some method of what you seek, I just want to make the point.

https://physics.stackexchange.com/quest … e%20vacuum.
Quote:

Electricity is a flow of electrons. Electrons can flow across a vacuum. The problem with doing this over a long range is that you need a force to get the electrons to travel across the vacuum.

As it happens, I was one of the last people to be trained in vacuum tubes, along with semiconductors.

So, a caution.  Some old stuff is buried under what worked better for a while.

As I have said, your test is not wrong, and methods to achieve the goal are not necessarily out of reach, but to some degree vacuum, and thin volumes of molecules in a relative vacuum can conduct electricity.

Done

Last edited by Void (2022-08-09 09:03:03)


Done.

Offline

#71 2022-08-09 10:29:49

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

For void re Post #70

Thank you for several things ...

First, thanks for your (for me unexpected) contribution to this topic!
Second, thank you for a glimpse of your background, and particularly experience with vacuum tubes
Third, thank you for the reminder that electrons can (and do) travel in a vacuum.

All that said, I am (somewhat anxiously) hoping you will stay engaged a bit longer, and consider the dielectric properties of vacuum.

The radiation protection system I am attempting to promote does not exist anywhere on Earth (to the best of my knowledge, which is necessarily limited).  It depends ** entirely ** upon the properties of vacuum as a dielectric.

If a vacuum is "spoiled" by the presence of stray ions, then it's dielectric properties will be diminished.

Thanks to your reminder, it occurs to me that the device may need a vacuum within a vacuum, or perhaps it will be more effective in deep space (where vacuum is less contaminated).

The device is a capacitor, and your brief glimpse of your background suggests you may be familiar with the properties of such devices.

The proposition for radiation protection, is to enlist the properties of static electric fields to repel charged ions.

In the reference cited previously, a voltage is given as sufficient to repel a galactic alpha particle traveling at half the speed of light.

The voltage is so high that (again, to my knowledge) no one has seriously pursued it.

However, the success of the James Webb cooling system shows that a set of thin sheets of material can be deployed in a vacuum, despite the difficulty.

What I am proposing would look a bit like the James Webb cooling system, with the difference that for the radiation protection application, the material of the layers would need to be conductive, so that electrons can be removed (for the positive side) and pushed onto the negative side.

The challenge in space is to keep the two sheets apart, because vacuum (by definition) will NOT oppose the two sheets coming together at the first opportunity.

Glass rods might be used to keep the sheets apart.

As you know from your experience, glass is often selected for applications where refusal to conduct electricity is a virtue.

In any case, I am hoping this subject continues to inspire your interest, and your creative thinking.

(th)

Offline

#72 2022-08-09 11:14:42

Void
Member
Registered: 2011-12-29
Posts: 6,975

Re: Large Ship Radiation Protection

Your quest is an interesting one.  I will need much more time to learn, to hope to contribute anything of value.  But I did know that a greater partial vacuum is not entirely an electric insulator.

I do have this query for you to try, if you haven't tried similar yet: "electrostatic radiation shielding"

I do think you may be on the right path with the use of glass for some components.

I will consider the work that members are doing here and see if anything possibly useful will pop up in my head.

Done.

Last edited by Void (2022-08-09 11:15:45)


Done.

Offline

#73 2022-08-09 14:29:25

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,781
Website

Re: Large Ship Radiation Protection

Radiation from the Sun is equal numbers protons and electrons. Both have a charge of one electron volt: protons positive, electrons negative. But a proton has 1836 times the mass of an electron. This means protons are harder to block, and do more damage. Human skin can stop electrons, they're not dangerous. With sufficient energy and sufficient concentration they can cause skin cancer, but election radiation in space is not that intense. Proton radiation is the danger. There is alpha radiation in solar wind, but a single sheet of aluminum foil can block that. Solar wind has se ion radiation. That's nuclei of atoms, with all their electrons stripped off. But solar radiation has very very little of that. Solar radiation is almost entirely proton and electron. You might expect some neutron radiation since nuclear reactions power the Sun, but those reactions are in the core of the Sun, not near the surface. The Sun has outer layers several times the diameter of the Earth where no nuclear reactions take place. Those thick dense layers prevent any neutron radiation from getting out. So that leaves proton radiation.

Cosmic radiation comes from outside our solar system. The Sun's magnetic field acts as a particle accelerator. Comic radiation doesn't have much more energy that solar radiation when it arrives, but by the time it reaches the inner solar system where Earth and Mars are, cosmic radiation has ten times the energy of solar radiation. Cosmic radiation has significant amounts of ion radiation, heavy ion radiation is mostly iron nuclei. This is nasty stuff, and it comes from all directions at once. Luckily there isn't much of it, and very little of it is heavy ions.

A mini-magnetosphere is a magnetic field from the spacecraft, enhanced by plasma. The plasma is trapped in the magnetic field and orbits the ship. Anything with charge that moves in a circle will generate a magnetic field. This extends the magnetic field thousands of kilometers from the ship. Plasma of the mini-magnetosphere blocks plasma from the Sun. Cosmic radiation will get through, but only needs to be deflected a degree or so to miss the ship since the field extends so far. I don't expect all cosmic radiation to miss the ship, but if 2/3 are deflected then radiation intensity will equal that on ISS.

Offline

#74 2022-08-09 21:09:39

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

For RobertDyck re #73

SearchTerm:Radiation from Sun

For Void ... thank you for the hint about a Google search ...

https://www.sciencedirect.com/science/a … 7707009659

Electrostatic space radiation shielding
Author links open overlay panel Ram K.Tripathi a John W.Wilson a Robert C.Youngquist b
https://doi.org/10.1016/j.asr.2007.09.015Get rights and content
Abstract
For the success of NASA’s new vision for space exploration to Moon, Mars and beyond, exposures from the hazards of severe space radiation in deep space long duration missions is ‘a must solve’ problem. The payload penalty demands a very stringent requirement on the design of the spacecrafts for human deep space missions. The exploration beyond low Earth orbit (LEO) to enable routine access of space will require protection from the hazards of the accumulated exposures of space radiation, Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE), and minimizing the production of secondary radiation is a great advantage. There is a need to look to new horizons for newer technologies. The present investigation revisits electrostatic active radiation shielding and explores the feasibility of using the electrostatic shielding in concert with the state-of-the-art materials shielding and protection technologies. The full space radiation environment has been used, for the first time, to explore the feasibility of electrostatic shielding. The goal is to repel enough positive charge ions so that they miss the spacecraft without attracting thermal electrons. Conclusions are drawn for the future directions of space radiation protection.

This paper appears to be well worth reading, in connection with the proposal to reject charged particles using a capacitor.

For RobertDyck .... the use of a magnetic field is certainly well worth considering, but at this point, to the best of my knowledge (limited as that is) no entity of any kind is using such a system, or even planning experiments to show it would actually work in space.

We are in the Large Ship Radiation Protection topic, so any discoveries a member might make of ongoing research or even speculation are welcome.

(th)

Offline

#75 2022-08-09 21:15:10

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 16,746

Re: Large Ship Radiation Protection

Here are more abstracts and citations that followed the paper on electrostatic radiation protection...

I note that both magnetic and electrostatic protection systems are considered, and even a hybrid system in the last citation...

Stabilization of a programmed rotation mode for a satellite with electrodynamic attitude control system
2018, Advances in Space Research
Citation Excerpt :
As conventional radiation shielding strategies based on bulk material have obvious drawbacks, the concept of active shielding based on the use of an electromagnetic field to deflect the charged particles from the protected volume of the satellite is an attractive alternative to passive material shielding (Sussingham et al., 1999). In particular, electrostatic space radiation shielding proposed in the 1960s (Trukhanov et al., 1970) has been actively studied and revised in the last few years due to recent technological improvements (Spillantini, 2007; Tripathi et al., 2008; Joshi et al., 2013a,b). The system of active electrostatic shielding is based on the use of electrostatically charged shield covering the protected volume and deflecting charged particles from the surface.

Show abstract
Evaluation of a combined electrostatic and magnetostatic configuration for active space-radiation shielding
2013, Advances in Space Research
Citation Excerpt :
The lower field intensities would have the added advantage of reduced power requirements. Here therefore, we probe one such hybrid configuration that uses twelve electrostatic spheres (similar to a configuration proposed by Tripathi et al., 2008), in concert with a current-carrying superconducting ring for a superimposed magnetic field. The geometry is shown in Fig. 1, and consists of six outer spheres held at a negative potential (−Vneg), six inner spheres held at a positive potential (Vpos), and superconducting ring (carrying a loop current I) for providing the magnetic field.

Show abstract
Configuration studies for active electrostatic space radiation shielding
2013, Acta Astronautica
Citation Excerpt :
Specifically, as shown in Fig. 1a, the configuration consists of three different inner rings kept at a positive voltage and six outer spheres. For comparison, the twelve-sphere geometry as previously reported [15] is also included in this contribution. The six outer negatively charged spheres are designed to play a role in repelling the free electrons from the solar wind [19].

Show abstract
View all citing articles on Scopus
View full text
Published by Elsevier Ltd.

(th)

Offline

Board footer

Powered by FluxBB