Re: high energy gammas?

["Christoph Hofmeyr" <Christoph_Hofmeyr@nnr.co.za>]

Miro,
Allow me to add my nickel:  I think Dave Brown has got the right answer(s).
The neutron capture observed in nickel would be in nuclide Ni-58, and in
chromium it would be in nuclide Cr-53, and the gammas you observed are the
strongest high-energy transitions in Ni-59 and Cr-54, respectively, excited
by (mostly thermal) neutron capture.  The iron doublet is a well-known
feature in neutron-capture gamma spectra.  The intensities quoted by Dave
Brown are probably with respect to capture of 100 neutrons in the specific
element (Ni - typo?)

Chris Hofmeyr
chofmeyr@nnr.co.za


You wrote:


                                                                                                
                    "Lieskovsky, Miro"                                                          
                    <MLieskovsky@nbpow        To:     Multiple recipients of list               
                    er.com>                   <radsafe@romulus.ehs.uiuc.edu>                    
                    Sent by:                  cc:     (bcc: Christoph Hofmeyr/CNS1)             
                    radsafe@romulus.eh        Subject:     high energy gammas?                  
                    s.uiuc.edu                                                                  
                                                                                                
                                                                                                
                    2000/08/22 18:53                                                            
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Dear Radsafers:

I looked into the higher energy HP Ge spectra (< ~8MeV) collected around
'active' systems of a nuclear plant and found the following peaks that I
can
not associate with nuclides:

1) 7633 keV (+- ~2.0 keV) with its Single Escape @ 7122 keV and Double
Escape @ 6611 keV
2) 7647 keV (+- ~2.0 keV) with SE @ 7136 keV and DE @ 6625 keV

Additionally;
the following peaks @ ~7864 and 7978 keV were present; these are likely the
DE ones, however, since the system gain was only up to approximately 8000
keV. I can not confirm.  If true then the full energy gamma lines would be
@
approximately 8886 and 9000.

The above peaks do not appear to be due to the summation effect.

Any help will be greatly appreciated.  Thank you in advance.

Miroslav Lieskovský
Health Physicist
NB POWER - PLGS
P.O. BOX 600
Lepreau, N.B.
Canada, E5J 2S6
Tel. (506) 659 7421
Fax. (506) 659 6981
mailto:mlieskovsky@nbpower.com
http://www.nbpower.com









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