How to convert MCNP-generated data

  • Thread starter Thread starter Hamidul
  • Start date Start date
Click For Summary
SUMMARY

The discussion focuses on converting MCNP-generated data to match the output of a Nested Neutron Spectrometer. The MCNP results are expressed in neutrons per square centimeter per source neutron, while the spectrometer measures neutron fluence in n/(cm²·s). To align these datasets, users should multiply the MCNP tally results by the source emission rate of 70,292,091 n/s from a Californium-252 source, taken at a distance of 100 cm. Additionally, it is crucial to consider whether the spectrometer data has been adjusted for its response function.

PREREQUISITES
  • Understanding of MCNP (Monte Carlo N-Particle Transport Code) and its tally systems
  • Familiarity with Nested Neutron Spectrometer operation and data output
  • Knowledge of neutron fluence measurement units (n/(cm²·s))
  • Basic principles of source emission rates and their application in data conversion
NEXT STEPS
  • Research the MCNP tally system, specifically f2 and f4 tallies
  • Learn about the response function of neutron spectrometers and its impact on data interpretation
  • Explore methods for converting neutron flux data to fluence rates
  • Investigate calibration techniques for spectrometer data to ensure accuracy
USEFUL FOR

Researchers, nuclear engineers, and physicists involved in neutron detection and data analysis, particularly those working with MCNP and neutron spectrometry.

Hamidul
Messages
27
Reaction score
5
TL;DR
Convert MCNP data to a practical spectrometer unit.
In MCNP, the flux value (f2 or f4 tally) comes with the flux per neutron. But in the practical spectrometer, the unit is different. How can I convert MCNP data that matches my spectrometer-generated data? When I go to plot both datasets, the units are different. However, my source emission rate is 70292091 n/s (252Cf). Below is the attached file of my MCNP-generated data. This data was taken at a distance of 100cm from the source. The source anisotropy according to the calibration certificate is 1.01. feel free to seek info that can be necessary.
 

Attachments

Engineering news on Phys.org
Hi @Hamidul,

What are the units of your spectrometer result and can you share that result?

MCNP results will be in neutrons per square cm per source neutron (I assume these tallies are for neutrons). So multiplying by the source activity is not a bad start.

You may need to know if the spectrometer result is adjusted for it's response function.
 
Hi
Alex A said:
Hi @Hamidul,

What are the units of your spectrometer result and can you share that result?

MCNP results will be in neutrons per square cm per source neutron (I assume these tallies are for neutrons). So multiplying by the source activity is not a bad start.

You may need to know if the spectrometer result is adjusted for it's response function.
Hi Alex, The spectrometer result is below. Here I am using a Nested Neutron Spectrometer. Here it measures neutron fluence (n/(cm^2*s). The data are taken for a bare Californium-252 neutron source at a distance of 100cm from the source.
Yes, the data are unfolded with the aid of the response function.
 

Attachments

Hamidul said:
Hi

Hi Alex, The spectrometer result is below. Here I am using a Nested Neutron Spectrometer. Here it measures neutron fluence (n/(cm^2*s). The data are taken for a bare Californium-252 neutron source at a distance of 100cm from the source.
Yes, the data are unfolded with the aid of the response function.
Hello @Alex
 
Hi @Hamidul,

Okay, so this is just testing the SDEF really at this point. When you multiply the MCNP tally results by your emission rate and put them side by side with the spectrometer result, what does it look like?
 

Similar threads

MCNP code for Neutron Spectroscopy
  • · Replies 17 ·
Replies
17
Views
3K
If MCNP tallies are normalized, shouldn't they be <1?
  • · Replies 5 ·
Replies
5
Views
3K
MCNP6.2 - How to plot normalized tallies with MCNP6.2?
  • · Replies 3 ·
Replies
3
Views
3K
MCNP Modelling Detector Energy Response Vs Empirical Results
  • · Replies 3 ·
Replies
3
Views
3K
Number of secondaries generated in a volume MCNP?
  • · Replies 2 ·
Replies
2
Views
2K
How to obtain MCNP tally data that is *not* normalized by nps
  • · Replies 1 ·
Replies
1
Views
3K
MCNP Cylindrical Phantom Calculation Help
  • · Replies 1 ·
Replies
1
Views
4K
Help With MCNP Volume definition
  • · Replies 4 ·
Replies
4
Views
3K
ABC reference frame synchronous generator modelling in Ltspice
  • · Replies 1 ·
Replies
1
Views
3K
Admissions Could I please get critique on my SOP? (Experimental Biophysics)
  • · Replies 8 ·
Replies
8
Views
945