Computing Neutron Source Strength - Your Advice Welcome

Click For Summary

Discussion Overview

The discussion revolves around computing the strength of an Am-Be neutron source in terms of neutrons per second. Participants explore various methods and factors that influence the calculation, including decay rates and cross-sections.

Discussion Character

  • Technical explanation, Experimental/applied, Debate/contested

Main Points Raised

  • Some participants suggest using the α decay rate of Am-241 along with the macroscopic cross-section and reaction efficiency to determine the neutron source strength.
  • Others mention that Amersham produces an Am-Be source with an approximate yield of 2.2 x 106 neutrons per Ci, noting the need to correct for Am-241 decay and the importance of knowing the original activity or manufacture date.
  • One participant references the Po-210/Be neutron source, stating it has a yield of 70 neutrons per million alpha particles as an example of a different neutron source.
  • A suggestion is made to consult a specific handbook for a conversion factor relevant to the calculations.

Areas of Agreement / Disagreement

Participants present multiple approaches and factors to consider, indicating that there is no consensus on a single method for calculating the neutron source strength.

Contextual Notes

Participants express varying assumptions regarding decay rates, cross-sections, and the need for correction factors, which may affect the accuracy of their calculations.

Stephan_doc
Messages
34
Reaction score
2
Greetings to all,
I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!
 
Engineering news on Phys.org
Stephan_doc said:
Greetings to all,
I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!
One could take the α decay rate of Am-241, and with knowledge of the macroscopic cross-section, including reaction efficiency, determine the n source term.

Alternatively, Amersham produces an Am-Be source of ~ 2.2 x 106 n/sec per Ci. This is the approximate value at manufacture, so one has to correct for Am-241 decay. One would have to know the Ci of Am of the original source, or the date of manufacture.
 
Thank you for answer, finally i found the solution. For example Po-210/Be neutrons-source has a yield of 70 neutrons/1milion alpha particles.
 
You need a conversion factor. Look at

Bernard Shlein, L. A. (1998). Handbook of Health Physics and Radiological Health Third Edition. Baltimore: Lippincott Williams and Wilkins.

Stephan_doc said:
Greetings to all,
I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!
 

Similar threads

What Is the Difference Between Angular Neutron Flux and Neutron Current Vector?
  • · Replies 2 ·
Replies
2
Views
3K
PTRAC File - MCNP - Multi-core computing
  • · Replies 1 ·
Replies
1
Views
2K
How to Calculate the Source Activity from Dose Rate in MCBEND
  • · Replies 0 ·
Replies
0
Views
3K
FLUKA: Why Does Neutron Flux Increase When Passing Through a Moderator?
  • · Replies 5 ·
Replies
5
Views
3K
Help Needed: Discrepancy in 2D Monte Carlo Neutron Transport Simulation
  • · Replies 1 ·
Replies
1
Views
1K
MCNP5, dose calculation, subcritical system
  • · Replies 2 ·
Replies
2
Views
2K
I need help please for Simulation of Xenon Oscillations in a Nuclear Reactor
  • · Replies 4 ·
Replies
4
Views
2K
Subcritical Reactor: An Analysis of Neutron Source Dynamics
  • · Replies 16 ·
Replies
16
Views
3K
Nuclear Chain Reaction Conditions
  • · Replies 6 ·
Replies
6
Views
3K
Neutron moderation in a Hydrogen medium and scattering
  • · Replies 15 ·
Replies
15
Views
5K