Activation - Revision history

Illirem at 14:18, 19 September 2025

2025-09-19T14:18:12Z

← Older revision		Revision as of 10:18, 19 September 2025
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	Particle Energy: The energy of the incident radiation influences the probability of activation. Certain isotopes have higher probabilities of activation at specific energies. This energy directly affects the cross-section.<br>		Particle Energy: The energy of the incident radiation influences the probability of activation. Certain isotopes have higher probabilities of activation at specific energies. This energy directly affects the cross-section.<br>
	Activation Cross-Section ( <math>~~\color{Black}~~ \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>~~\color{Black}~~ 1\;barn </math> is equal to <math>~~\color{Black}~~ 1E-24\;cm^2</math>.		Activation Cross-Section ( <math> \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math> 1\;barn </math> is equal to <math>1E-24\;cm^2</math>.

	Particle Fluence ( <math>~~\color{Black}~~ \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.		Particle Fluence ( <math> \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.

	Target Atoms ( <math>~~\color{Black}~~ N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.		Target Atoms ( <math> N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.

	Decay Constant ( <math>~~\color{Black}~~ \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\~~color{Black}~~ \lambda = ln(2)/T_{1/2}</math>		Decay Constant ( <math> \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\ \lambda = ln(2)/T_{1/2}</math>

	Irradiation Time ( <math>~~\color{Black}~~ t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>~~\color{Black}~~ t_1 </math> equal to 5x the half life.		Irradiation Time ( <math> t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math> t_1 </math> equal to 5x the half life.

	Time since Irradiation ( <math>\color{Black} t_2\;[sec]</math> ) : The value for <math>\color{Black} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.		Time since Irradiation ( <math>\color{Black} t_2\;[sec]</math> ) : The value for <math>\color{Black} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.

Illirem at 14:16, 19 September 2025

2025-09-19T14:16:14Z

← Older revision		Revision as of 10:16, 19 September 2025
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	The process of activation can be understood through the following simplified nuclear equation:		The process of activation can be understood through the following simplified nuclear equation:

	<math>~~\color{Black}~~ A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>		<math>A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>

Illirem at 14:14, 19 September 2025

2025-09-19T14:14:07Z

Illirem: /* Neutron Activation Examples */

2024-12-30T13:56:05Z

Neutron Activation Examples

← Older revision		Revision as of 09:56, 30 December 2024
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	*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]		*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]

	=Neutron Activation ~~Examples~~=		=Neutron Activation Example=
	To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>. Assume that there is a fluence of 2.7E15 neutrons/sec and they are all thermalized.		To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>. Assume that there is a fluence of 2.7E15 neutrons/sec and they are all thermalized.

Illirem: /* Neutron Activation Examples */

2024-12-26T00:46:36Z

Neutron Activation Examples

← Older revision		Revision as of 20:46, 25 December 2024
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	=Neutron Activation Examples=		=Neutron Activation Examples=
	To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.		To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>. Assume that there is a fluence of 2.7E15 neutrons/sec and they are all thermalized.

	<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>		<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>
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	Particle Energy: The ~~energy of the incident radiation influences the probability of activation~~. ~~Certain isotopes have higher probabilities of activation at specific energies~~. ~~This energy directly affects the cross~~-~~section~~.<br>		Particle Energy: The neutrons are thermalized, which at STP means 0.025 eV, or 2.5E-8 MeV. <br>
	Activation Cross-Section ( <math>\color{White} \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{White} 1\;barn </math> is equal to <math>\color{White} 1E-24\;cm^2</math>.		Activation Cross-Section ( <math>\color{White} \sigma\;[barn]</math> ): Using the [https://www-nds.iaea.org/exfor/endf.htm IAEA ENDF database]

			An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{White} 1\;barn </math> is equal to <math>\color{White} 1E-24\;cm^2</math>.

	Particle Fluence ( <math>\color{White} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.		Particle Fluence ( <math>\color{White} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.
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	Irradiation Time ( <math>\color{White} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{White} t_1 </math> equal to 5x the half life.		Irradiation Time ( <math>\color{White} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{White} t_1 </math> equal to 5x the half life.

	Time since Irradiation ( <math>\color{White} t_2\;[sec]</math> ) : The value for <math>\color{White} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.		Time since Irradiation ( <math>\color{White} t_2\;[sec]</math> ) : The value for <math>\color{White} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.




	=Proton Activation Examples=		=Proton Activation Examples=

Illirem at 23:40, 25 December 2024

2024-12-25T23:40:45Z

← Older revision		Revision as of 19:40, 25 December 2024
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	To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.		To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.

	~~The nuclear activation equation is~~<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>		<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>

			Replicating the equation above we can step through the variables
			<math>\color{White} A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>


			Particle Energy: The energy of the incident radiation influences the probability of activation. Certain isotopes have higher probabilities of activation at specific energies. This energy directly affects the cross-section.<br>
			Activation Cross-Section ( <math>\color{White} \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{White} 1\;barn </math> is equal to <math>\color{White} 1E-24\;cm^2</math>.

			Particle Fluence ( <math>\color{White} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.

			Target Atoms ( <math>\color{White} N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.

			Decay Constant ( <math>\color{White} \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\color{White} \lambda = ln(2)/T_{1/2}</math>

			Irradiation Time ( <math>\color{White} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{White} t_1 </math> equal to 5x the half life.

			Time since Irradiation ( <math>\color{White} t_2\;[sec]</math> ) : The value for <math>\color{White} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.




	=Proton Activation Examples=		=Proton Activation Examples=
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	=Future Additions=		=Future Additions=
	This section provides a basic introduction to material activation. Further exploration could include:		This section provides a basic introduction to material activation. Further exploration could include:
	:Specific examples of activation products in different industries (e.g., medical, industrial, research)		*Specific examples of activation products in different industries (e.g., medical, industrial, research)
	:Detailed discussion of activation cross-sections and their importance		*Detailed discussion of activation cross-sections and their importance
	:Methods for measuring and monitoring activation levels		*Methods for measuring and monitoring activation levels
	:Strategies for minimizing and managing activation in various settings		*Strategies for minimizing and managing activation in various settings
	~~I am only one editor/contributor at~~ the ~~moment, but I want to document my aspirations for~~ the ~~future of the site.~~		*Properly format the nuclear equations in the examples with simultaneous sup/sub scripts

Illirem: /* Neutron Activation Examples */

2024-12-25T23:30:50Z

Neutron Activation Examples

← Older revision		Revision as of 19:30, 25 December 2024
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	To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.		To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.

	The nuclear activation equation is<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}~~O\;+\gamma\;+\beta~~</math>		The nuclear activation equation is<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>

	=Proton Activation Examples=		=Proton Activation Examples=

Illirem: /* Neutron Activation Examples */

2024-12-25T23:27:54Z

Neutron Activation Examples

← Older revision		Revision as of 19:27, 25 December 2024
Line 51:		Line 51:

	=Neutron Activation Examples=		=Neutron Activation Examples=
	To exercise the knowledge from this section we can evaluate the production of <math> \color{White} .^{16}N </math> from the neutron absorption of <math> \color{White} ^{16}O </math>.		To exercise the knowledge from this section we can evaluate the production of<math> \color{White}\;^{16}N </math> from the neutron absorption of<math> \color{White} \;^{16}O </math>.

			The nuclear activation equation is<math> \color{White} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}O\;+\gamma\;+\beta</math>

	=Proton Activation Examples=		=Proton Activation Examples=

Illirem at 23:15, 25 December 2024

2024-12-25T23:15:40Z

← Older revision		Revision as of 19:15, 25 December 2024
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	*[https://en.wikipedia.org/wiki/Neutron_capture Wikipedia page on Neutron Capture]		*[https://en.wikipedia.org/wiki/Neutron_capture Wikipedia page on Neutron Capture]
	*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]		*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]

	~~<math> \color{White} v^{16}O </math>~~

	=Neutron Activation Examples=		=Neutron Activation Examples=
	To exercise the knowledge from this section we can evaluate the production of <math> \color{White} ^{16}N </math> from the neutron absorption of <math> \color{White} ^{16}O </math>.		To exercise the knowledge from this section we can evaluate the production of <math> \color{White} .^{16}N </math> from the neutron absorption of <math> \color{White} ^{16}O </math>.

	=Proton Activation Examples=		=Proton Activation Examples=

Illirem at 23:12, 25 December 2024

2024-12-25T23:12:24Z

← Older revision		Revision as of 19:12, 25 December 2024
Line 49:		Line 49:
	*[https://en.wikipedia.org/wiki/Neutron_capture Wikipedia page on Neutron Capture]		*[https://en.wikipedia.org/wiki/Neutron_capture Wikipedia page on Neutron Capture]
	*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]		*[https://en.wikipedia.org/wiki/Proton_capture Wikipedia page on Proton Capture]

			<math> \color{White} v^{16}O </math>

	=Neutron Activation Examples=		=Neutron Activation Examples=

← Older revision		Revision as of 10:14, 19 September 2025
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	The process of activation can be understood through the following simplified nuclear equation:		The process of activation can be understood through the following simplified nuclear equation:

	<math>\color{~~White~~} A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>		<math>\color{Black} A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>


	Particle Energy: The energy of the incident radiation influences the probability of activation. Certain isotopes have higher probabilities of activation at specific energies. This energy directly affects the cross-section.<br>		Particle Energy: The energy of the incident radiation influences the probability of activation. Certain isotopes have higher probabilities of activation at specific energies. This energy directly affects the cross-section.<br>
	Activation Cross-Section ( <math>\color{~~White~~} \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{~~White~~} 1\;barn </math> is equal to <math>\color{~~White~~} 1E-24\;cm^2</math>.		Activation Cross-Section ( <math>\color{Black} \sigma\;[barn]</math> ): An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{Black} 1\;barn </math> is equal to <math>\color{Black} 1E-24\;cm^2</math>.

	Particle Fluence ( <math>\color{~~White~~} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.		Particle Fluence ( <math>\color{Black} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.

	Target Atoms ( <math>\color{~~White~~} N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.		Target Atoms ( <math>\color{Black} N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.

	Decay Constant ( <math>\color{~~White~~} \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\color{~~White~~} \lambda = ln(2)/T_{1/2}</math>		Decay Constant ( <math>\color{Black} \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\color{Black} \lambda = ln(2)/T_{1/2}</math>

	Irradiation Time ( <math>\color{~~White~~} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{~~White~~} t_1 </math> equal to 5x the half life.		Irradiation Time ( <math>\color{Black} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{Black} t_1 </math> equal to 5x the half life.

	Time since Irradiation ( <math>\color{~~White~~} t_2\;[sec]</math> ) : The value for <math>\color{~~White~~} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.		Time since Irradiation ( <math>\color{Black} t_2\;[sec]</math> ) : The value for <math>\color{Black} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.

	'''Assumptions'''		'''Assumptions'''
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	While this topic is typicall called neutron absorption or neutron activation, there is a long list of nuclear reactions which can result in the activation of the target isotope. [https://www-nds.iaea.org/exfor/helpe/help_reaction.htm Linked here] is a list of many possible nuclear reactions for which there may be Evaluated Nuclear Data Files (ENDF)s which will provide cross section values as a function of the nuclear reaction, target, and incident radiation energy.		While this topic is typicall called neutron absorption or neutron activation, there is a long list of nuclear reactions which can result in the activation of the target isotope. [https://www-nds.iaea.org/exfor/helpe/help_reaction.htm Linked here] is a list of many possible nuclear reactions for which there may be Evaluated Nuclear Data Files (ENDF)s which will provide cross section values as a function of the nuclear reaction, target, and incident radiation energy.

	There is a limit to the maximum amount of product material which may be produced, called the saturation activity. The saturation activity for the general equation occurs when time approaches infinity or half life approaches zero. This elimitates the exponential term and reduces to <math>\color{~~White~~} A = \sigma * \varphi * N</math>. A general rule of thumb is that saturation occurs after 5 half lives.		There is a limit to the maximum amount of product material which may be produced, called the saturation activity. The saturation activity for the general equation occurs when time approaches infinity or half life approaches zero. This elimitates the exponential term and reduces to <math>\color{Black} A = \sigma * \varphi * N</math>. A general rule of thumb is that saturation occurs after 5 half lives.

	The following presentation from the NRC provides a good overview of neutron activation and activation analysis.		The following presentation from the NRC provides a good overview of neutron activation and activation analysis.
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	=Neutron Activation Example=		=Neutron Activation Example=
	To exercise the knowledge from this section we can evaluate the production of<math> \color{~~White~~}\;^{16}N </math> from the neutron absorption of<math> \color{~~White~~} \;^{16}O </math>. Assume that there is a fluence of 2.7E15 neutrons/sec and they are all thermalized.		To exercise the knowledge from this section we can evaluate the production of<math> \color{Black}\;^{16}N </math> from the neutron absorption of<math> \color{Black} \;^{16}O </math>. Assume that there is a fluence of 2.7E15 neutrons/sec and they are all thermalized.

	<math> \color{~~White~~} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>		<math> \color{Black} \;^{16}O\;+\;^{1}n\;\longrightarrow\;^{16}N</math>

	Replicating the equation above we can step through the variables		Replicating the equation above we can step through the variables
	<math>\color{~~White~~} A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>		<math>\color{Black} A = \sigma * \varphi * N(1-e^{(-\lambdat_1)})e^{(-\lambdat_2)} </math>


	Particle Energy: The neutrons are thermalized, which at STP means 0.025 eV, or 2.5E-8 MeV. <br>		Particle Energy: The neutrons are thermalized, which at STP means 0.025 eV, or 2.5E-8 MeV. <br>
	Activation Cross-Section ( <math>\color{~~White~~} \sigma\;[barn]</math> ): Using the [https://www-nds.iaea.org/exfor/endf.htm IAEA ENDF database]		Activation Cross-Section ( <math>\color{Black} \sigma\;[barn]</math> ): Using the [https://www-nds.iaea.org/exfor/endf.htm IAEA ENDF database]

	An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{~~White~~} 1\;barn </math> is equal to <math>\color{~~White~~} 1E-24\;cm^2</math>.		An inherent property of the target material that describes the probability of a nucleus interacting with a neutron. The unit of <math>\color{Black} 1\;barn </math> is equal to <math>\color{Black} 1E-24\;cm^2</math>.

	Particle Fluence ( <math>\color{~~White~~} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.		Particle Fluence ( <math>\color{Black} \varphi\;[particles \bullet sec^{-1} </math> ): The intensity of the incident radiation field. Higher flux leads to faster activation.

	Target Atoms ( <math>\color{~~White~~} N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.		Target Atoms ( <math>\color{Black} N \;[atoms]</math> ): The number of atoms onto which the particle flux is incident.

	Decay Constant ( <math>\color{~~White~~} \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\color{~~White~~} \lambda = ln(2)/T_{1/2}</math>		Decay Constant ( <math>\color{Black} \lambda \;[sec^{-1}]</math> ) : This is the decay constant of the activation product which will determin how long it will take to approach saturation activity and how long the activation product will remain radioactive. <math>\color{Black} \lambda = ln(2)/T_{1/2}</math>

	Irradiation Time ( <math>\color{~~White~~} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{~~White~~} t_1 </math> equal to 5x the half life.		Irradiation Time ( <math>\color{Black} t_1\;[sec]</math> ) : The time during which the material is irradiated by the particle fluence above. The longer the material is exposed to fluence, the more activation will occur. The activation will approach a saturated activity after a <math>\color{Black} t_1 </math> equal to 5x the half life.

	Time since Irradiation ( <math>\color{~~White~~} t_2\;[sec]</math> ) : The value for <math>\color{~~White~~} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.		Time since Irradiation ( <math>\color{Black} t_2\;[sec]</math> ) : The value for <math>\color{Black} t_2 </math> is the time since the end of irradiation. This term is simply a radioactive decay term which accounts for the natural decay of the activation product.

	=Proton Activation Examples=		=Proton Activation Examples=