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Posted

hi,

can someone explain please whether there are steady metals. 

The property I look for is about being steady across (nuclear) radiation,too.

but as this issue does not fall inside the areas of my interests, I think i can easily make some mistakes. if this is a case, I kindly  request the correction and understanding. 

Thanks

Posted (edited)
1 hour ago, swansont said:

What do you mean by steady?

Not affected by outside influences?

I might have used wrong term here, not sure.

by steady I mean the strong effect as a force across radiation ( when that metals are exposed to alpha, betta , gamma radiation)

Edited by ahmet
Posted

All material itself get radioactive, if exposed longer time to any of radiation. So there will be no steady material, metals and others.

Posted
1 hour ago, chenbeier said:

All material itself get radioactive, if exposed longer time to any of radiation. So there will be no steady material, metals and others.

This is not true, EM radiation cannot make any atom's nucleus unstable, it takes particles like neutrons or protons to actually make another atom radioactive. 

Posted
3 hours ago, ahmet said:

by steady I mean the strong effect as a force across radiation ( when that metals are exposed to alpha, betta , gamma radiation)

This is a very broad topic. Particle type is one issue (you forgot a few decay types, proton emission, neutron emission, neutrino capture to name a few), but the most important is kinetic energy of the incoming particle. If charged particle has too few energy it won't e.g. pass through Coulomb's barrier, kinetic energy will be lost on ejecting electrons etc. Some materials are "good" at capturing certain particles with certain kinetic energies, and other are "bad". It is analyzed by looking at the number of protons, the number of neutrons, spin, cross section, disintegration energy, etc. etc. In this way, for example, a neutron absorber and neutron mirror / neutron reflector can be created. For certain neutrons with the right kinetic energy (thermal neutrons, fast neutrons)..

 

What a low, medium and high energy photon can do to matter:

 

Gold protects astronauts against cosmic radiation:

https://www.google.com/search?q=gold+shield+against+cosmic+radiation

..and water too..

https://www.google.com/search?q=water+radiation+shield+against+cosmic+radiation

 

 

 

  

38 minutes ago, Moontanman said:

This is not true, EM radiation cannot make any atom's nucleus unstable, it takes particles like neutrons or protons to actually make another atom radioactive. 

Learn something new. It is called photodisintegration.

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

"Photodisintegration (also called phototransmutation, or a photonuclear reaction) is a nuclear process in which an atomic nucleus absorbs a high-energy gamma ray, enters an excited state, and immediately decays by emitting a subatomic particle."

 

For instance, Deuterium needs 2.2+ MeV gamma photon to disintegrate into free proton and free neutron.

https://www.google.com/search?q=Deuterium+needs+"2.2+MeV"

 

Nuclear isomer has the same number of protons and neutrons as stable (ground) isotope, but it decays via gamma emission:

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

 

ps. I encourage you to read all the links I provided before responding.

Posted
16 minutes ago, Sensei said:

Learn something new. It is called photodisintegration.

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

"Photodisintegration (also called phototransmutation, or a photonuclear reaction) is a nuclear process in which an atomic nucleus absorbs a high-energy gamma ray, enters an excited state, and immediately decays by emitting a subatomic particle."

 

For instance, Deuterium needs 2.2+ MeV gamma photon to disintegrate into free proton and free neutron.

https://www.google.com/search?q=Deuterium+needs+"2.2+MeV"

Thank you sensei, I was unaware of the photodisintegration via high energy gamma rays... exactly where in the natural environment would you expect to see such high energy gamma rays? While I acknowledge that you are correct I was going by what the atomic energy commision says about nuclear fallout, em radiation doesn't cause radioactivity in stable atoms.  BTW do protons disintegrate into neutrons under this extreme gamma ray flux? 

 

2 hours ago, chenbeier said:

All material itself get radioactive, if exposed longer time to any of radiation. So there will be no steady material, metals and others.

Again, this is not true, only very high energy gamma rays can photo disintegrate a nucleus... Not "any of radiation", no matter how long exposed. Under normal Earth conditions only particle radiation can cause a nucleus to become radioactive.       

Posted
4 minutes ago, Moontanman said:

exactly where in the natural environment would you expect to see such high energy gamma rays?

..space.. which is.. almost. everywhere..

https://www.google.com/search?q=gamma+ray+dectector+on+the+earth

 

Gamma ray detectors.

https://en.wikipedia.org/wiki/Oh-My-God_particle

"The Oh-My-God particle was an ultra-high-energy cosmic ray detected on 15 October 1991 by the Fly's Eye camera in Dugway Proving Ground, Utah, United States.[1][2][3] As of 2024, it is the highest-energy cosmic ray ever observed.[4] Its energy was estimated as (3.2±0.9)×10^20 eV (320 exa-eV). The particle's energy was unexpected and called into question prevailing theories about the origin and propagation of cosmic rays."

 

https://en.wikipedia.org/wiki/Ultra-high-energy_gamma_ray

"Ultra-high-energy gamma rays are gamma rays with photon energies higher than 100 TeV (0.1 PeV)."

 

Posted
38 minutes ago, chenbeier said:

Did I said something different.

Yes, you said, "All material itself get radioactive, if exposed longer time to any of radiation."

Moontanman said, "it takes particles like neutrons or protons to actually make another atom radioactive."

Posted
6 minutes ago, Sensei said:

..space.. which is.. almost. everywhere..

https://www.google.com/search?q=gamma+ray+dectector+on+the+earth

So we can observe these particles actively disintegrating atomic nucleus or are you saying we can detect the tiny amounts of this high energy radiation when it reaches the earth? 

6 minutes ago, Sensei said:

 

Gamma ray detectors.

https://en.wikipedia.org/wiki/Oh-My-God_particle

"The Oh-My-God particle was an ultra-high-energy cosmic ray detected on 15 October 1991 by the Fly's Eye camera in Dugway Proving Ground, Utah, United States.[1][2][3] As of 2024, it is the highest-energy cosmic ray ever observed.[4] Its energy was estimated as (3.2±0.9)×10^20 eV (320 exa-eV). The particle's energy was unexpected and called into question prevailing theories about the origin and propagation of cosmic rays."

The "oh my god particle" was not a gamma ray, cosmic rays are atomic nuclei accelerated to within a tiny fraction of the speed of light.   

6 minutes ago, Sensei said:

 

https://en.wikipedia.org/wiki/Ultra-high-energy_gamma_ray

"Ultra-high-energy gamma rays are gamma rays with photon energies higher than 100 TeV (0.1 PeV)."

 

 

Get back to me when you figure out the difference between cosmic rays and gamma rays. 

Posted
17 minutes ago, Sensei said:

There is (currently) a rare decay mode of positron emission:

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

 

 

Thank you, I was unaware of that decay path, particle physics and other related things are not in my area of expertise in any way but it still fascinates me. I read about it every chance I get. There is always something new to be learned and it's reasonably clear how it works... just facinting! 

Posted
5 hours ago, Bufofrog said:

Yes, you said, "All material itself get radioactive, if exposed longer time to any of radiation."

Moontanman said, "it takes particles like neutrons or protons to actually make another atom radioactive."

I referred to the initial question, if material is exposed to alpha, beta or gamma rays . Nothing more, if it was unclear then I say sorry.

Posted
7 hours ago, chenbeier said:

I referred to the initial question, if material is exposed to alpha, beta or gamma rays . Nothing more, if it was unclear then I say sorry.

In general alpha, beta or gamma rays will not cause a material to become radioactive.

Posted (edited)

If so then would be radiation no problem. Why the people afraid of nuclear power then.

My expierence is:  a cupboard in the lab got radiation where a container of K40 chloride  was stored. It emittes gamma, beta - and  beta+. What is your explanation for it.

Why the people in Japan afraid to get the Tritium water from Fukoshima into the sea?

Edited by chenbeier
Posted
3 minutes ago, chenbeier said:

If so then would be radiation no problem. Why the people afraid of nuclear power then.

Radiation can kill you or give you cancer even though that radiation (depending on the type)will not make your body radioactive.  So high doses of radiation are dangerous.

Nuclear power produces radioactive sources.  Those radioactive sources are dangerous.  The neutron radiation from fission causes the metals in the reactor and the supporting components to become radioactive.  The spent nuclear fuel is full of fission products that are also highly radioactive. 

Posted

Back to the original issue-

The most likely mode of making a material radioactive is neutron absorption (called neutron activation) and most materials are susceptible to this. The exceptions tend not to be metals.

The ones with the smallest absorption cross-section would likely be those with a “magic number” of neutrons, i.e. they have a filled shell of neutrons already.

Hafnium has several stable isotopes, so neutron absorption will usually result in a stable isotope. (it’s used in some nuclear reactor control rods partly for this reason)

Posted
1 hour ago, chenbeier said:

Why the people in Japan afraid to get the Tritium water from Fukoshima into the sea?

It is pretty simple. If you drink such water, Tritium (with half-live 12.3y) becomes part of your body instead of Hydrogen, and decays inside of your body, destroying your cells and/or the DNA of which it is a part.. If fishes or sea plants are contaminated by it, and you, or animal will drink it, or eat fish, you will be contaminated indirectly..

https://www.google.com/search?q=tritium+contamination

 

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