Re: [Vo]:Relationship between Slow neutron capture cross section and neutron spallation energy

2016-05-20 Thread Stephen Cooke
Very interesting link too, I'm just reading it. Are you based in the 
Netherlands by any chance?

Sent from my iPad

> On 20 mei 2016, at 23:40, mix...@bigpond.com wrote:
> 
> In reply to  Stephen Cooke's message of Fri, 20 May 2016 12:04:22 +0200:
> Hi,
> [snip]
>> Is there a relationship between the cross-section for slow neutron capture 
>> in particular nuclei and the nucleus excitation energy needed in the nucleus 
>> to cause neutron spallation?
>> 
>> For example B10 has a high neutron cross-section. Is there s relationship 
>> between this and the energy needed for Neutron spallation from B11?
> 
> That's what I would expect too. Nuclei with a high neutron capture 
> cross-section
> really "want" to have that extra neutron, because they become much more 
> stable.
> Conversely, removing the neutron from the new stable nucleus should be very
> difficult.
> Compare the neutron capture energy release with that of other nuclei. I would
> expect it to be larger.
> 
> In this case, 10B+n => 11B + 11.454 MeV
> 
> (That's a lot for a single particle capture reaction).
> 
> Another high capture cross-section reaction is:-
> 
> 3He+n => 4He + 20.578 MeV
> 
> which is why He3 is used in some neutron detectors.
> 
> Regards,
> 
> Robin van Spaandonk
> 
> http://rvanspaa.freehostia.com/project.html
> 



Re: [Vo]:Relationship between Slow neutron capture cross section and neutron spallation energy

2016-05-20 Thread Stephen Cooke
Thanks Robin, 

> On 20 mei 2016, at 23:40, mix...@bigpond.com wrote:
> 
> In reply to  Stephen Cooke's message of Fri, 20 May 2016 12:04:22 +0200:
> Hi,
> [snip]
>> Is there a relationship between the cross-section for slow neutron capture 
>> in particular nuclei and the nucleus excitation energy needed in the nucleus 
>> to cause neutron spallation?
>> 
>> For example B10 has a high neutron cross-section. Is there s relationship 
>> between this and the energy needed for Neutron spallation from B11?
> 
> That's what I would expect too. Nuclei with a high neutron capture 
> cross-section
> really "want" to have that extra neutron, because they become much more 
> stable.
> Conversely, removing the neutron from the new stable nucleus should be very
> difficult.
> Compare the neutron capture energy release with that of other nuclei. I would
> expect it to be larger.
> 
> In this case, 10B+n => 11B + 11.454 MeV
> 
> (That's a lot for a single particle capture reaction).
> 
> Another high capture cross-section reaction is:-
> 
> 3He+n => 4He + 20.578 MeV
> 
> which is why He3 is used in some neutron detectors.
> 
> Regards,
> 
> Robin van Spaandonk
> 
> http://rvanspaa.freehostia.com/project.html
> 



Re: [Vo]:Relationship between Slow neutron capture cross section and neutron spallation energy

2016-05-20 Thread mixent
In reply to  Stephen Cooke's message of Fri, 20 May 2016 12:04:22 +0200:
Hi,
[snip]
>Is there a relationship between the cross-section for slow neutron capture in 
>particular nuclei and the nucleus excitation energy needed in the nucleus to 
>cause neutron spallation?
>
>For example B10 has a high neutron cross-section. Is there s relationship 
>between this and the energy needed for Neutron spallation from B11?

That's what I would expect too. Nuclei with a high neutron capture cross-section
really "want" to have that extra neutron, because they become much more stable.
Conversely, removing the neutron from the new stable nucleus should be very
difficult.
Compare the neutron capture energy release with that of other nuclei. I would
expect it to be larger.

In this case, 10B+n => 11B + 11.454 MeV

(That's a lot for a single particle capture reaction).

Another high capture cross-section reaction is:-

3He+n => 4He + 20.578 MeV

which is why He3 is used in some neutron detectors.

Regards,

Robin van Spaandonk

http://rvanspaa.freehostia.com/project.html



[Vo]:Relationship between Slow neutron capture cross section and neutron spallation energy

2016-05-20 Thread Stephen Cooke
Is there a relationship between the cross-section for slow neutron capture in 
particular nuclei and the nucleus excitation energy needed in the nucleus to 
cause neutron spallation?

For example B10 has a high neutron cross-section. Is there s relationship 
between this and the energy needed for Neutron spallation from B11?