|Message: Re: problem absorption thermal neutrons by boron layer||Not Logged In (login)|
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On Thu, 26 Jan 2017 11:31:37 GMT, Giuseppe Vitucci wrote:
> I got a problem regarding the absorption percentage of thermal neutrons > (0.025 eV) launched towards a layer (0.01 cm) of natural boron. > > According to the Beer-Lambert law, after having properly designed the > neutron beam energy and the boron layer, I should get a percentage of > absorbed neutrons equal to 36% more or less, and I confirmed my > calculation looking elsewhere also (like here > https://www.ncnr.nist.gov/resources/activation/ ). > > The problem is that I always get the value of 13%, i tried simulating > 10000 neutrons and even more, but the result is stucked at that value. I > really don't know why. > > I am currently using QGSP_BERT_HP as physics list, but i tried several > others without success. > > Is there something that I am thinking in a wrong way? Do you have some > hint about something I should try to debug such problem? > > I had a look on the internet and it seems that Geant4 has some problem > simulating the physical behaviour of thermal neutrons, but for what I > understood the difference is supposed to be on few percentage points, > not tens. >
You can double check the cross sections with example Hadr03 and attached macro boron3.mac.txt Then you can run Hadr06 with boron6.mac.txt You can do the same thing with Hadr07 and boron7.mac.txt (if you have G4 10.3)
Attachment: http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2017/01/27/10.57-46554-boron3.mac.txt http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2017/01/27/10.57-96267-boron6.mac.txt http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2017/01/27/10.57-73733-boron7.mac.txt