Temperature in MCNP - Using Library ENDF7 for Research Reactor

[chivasorn]

Hi there,
I want to know that how can involve the temperature in mcnp code.
for example; the library endf7 for mcnp has five certain temperature:300 kelvin, 600 kelvin, 900 kelvin, 1200 kelvin & 1500 kelvin. if I want to calculate flux distribution in 330 kelvin for a research reactor, how can I?

best regards

 

[Astronuc]

Is there no temperature dependence functions.

One could interpolate, or given than 330 K is ~ 300 K, simply use 300 K. The Doppler broadening shouldn't be too significant going from 300 K to 330 K. The density changes are not very significant either.

 

[chivasorn]

Hi Astronuc.
I have another question; TMP card in MCNP that can be entered at cell card have not any effect in result of calculations?
Please, more explain about that, I need.

have best time.

 

[saqii99]

TMP card is used for the energy of thermal neutrons so you have have to accommodate the material temperatures

 

[AyeeGG]

Hi..

for temperature, there is a nuclear code to produce the library for it...
an NJOY, but it some kind of rare code...

by MODUL ACER, you can create the applicable data for any temperature...and it is also applicable for WIMS...

but, I do agree with Mr. Astronuc...

 

[MCNPX]

If the value of TMP parameter (or its default value if not given explicitly) in a cell card differs from temperature of nuclide in cross-section file, then MCNP modifies the nuclide cross-section using free-gas treatment (you can see a warning message during execution and in output file). It resets temperature to the room temp. and then (if a TMP value given) to the requested temperature. I haven't dug into this problem, but from what I heard, the free-gas treatment is not very precise procedure. The treatment happens even if you have difference in the last digit, i.e. negligible. This can potentially produce unnecessary discrepancy in your results. Please, correct me if it is wrong.

Hi Astronuc.
I have another question; TMP card in MCNP that can be entered at cell card have not any effect in result of calculations?
Please, more explain about that, I need.

have best time.