# Re: RES: [fluka-discuss]: Statistical error

Date: Tue, 8 Mar 2016 18:48:34 +0330 (IRST)

Dear Marlon,

You introduces FS "%dose-Eq em uSv/h, where FS is my conversion factor" in the Matlab Manuscript that you sent. I did this conversion for my case, the shield of a continuous 12uA, 10MeV Electron beam hitting the 3mm copper. For doing this conversion from pSv/Primary to uSv/h with the goal of comparing the dose rate after shield with the standard safe value of 10uSv/h for radiation workers.

A = 12e-6 (The electron beam current in my case)
B = 6.25e18 (Current(A) is Ampere (coulomb/s) and B is the number of electrons per Coulomb)
Y = 10e-6 (Y is the pSv to uSv conversion)
T = 72e5 (T is the conversion of a year to second: 1year=72e5 s)
M = 2000 (M is a year to hour converter, a year has 40 working weeks and 8hour working hour per week, 1year=2000h)
CoFa =(A*B*Y*T)/M (CoFa is conversion factor of pSv/primary to uSv/h)
CoFa =27e10

I was expecting to reach the standard safe level of 10uSv/h with 84cm concrete thickness for the forward wall in my case, considering and calculating from the Fig 10 of http://www.sciencedirect.com/science/article/pii/0020708X71901566.

While as the attachment file shows the Dose rate after the forward wall (after 150cm concrete thickness) reach to more that 1000uSv/h. I don't get what is not working well, the simulation, the conversion factor that I used, explained above, explained above, or my expectation that was came from Fig.10 of the above paper link.

Dear Marlon, Vittori and All Your suggestions are welcome.

----- Original Message -----
From: "Marlon Saveri Silva" <marlon.saveri_at_lnls.br>
Cc: "fluka-discuss" <fluka-discuss_at_fluka.org>
Sent: Tuesday, March 8, 2016 3:18:31 PM
Subject: RES: [fluka-discuss]: Statistical error

Dear Masoomeh,

I'm not sure if I've understood your question, but maybe I could help a little about plotting USRBIN Error:

When you use a USRBIN card (for example, using unit 82 BIN), and plot the result using Flair/Plot, it will generate an output file named ...82_plot.dat (and not "... 82_plot.geo.dat"). In such file, there's DOSE and Error related to that interval you plotted (defined in "Projection & Limits")
This file present 4 columns: first and second with bin coordinates; third with DOSE, DOSE-EQ (type of particle/information you are recording at USRBIN) and fourth column present the error.
You can plot the error, for example, using MATLAB:

clc; clear; close all; fclose('all');
MyData=load('My_file_plot_dat.txt'); %Import file (I use to convert to txt, but perhaps it's not necessary)
%% Input about number of bins (in my case, I'd plotted in X plane)
Ybin=301; %number of bins in Y
Zbin=201; %number of bins in Z
%%
Z=zeros(Zbin,1);
Y=zeros(Ybin,1);
for i=1:Zbin
for j=1:Ybin
Z(i)=MyData((i-1)*Ybin+j,1); %position Z
Y(j)=MyData((i-1)*Ybin+j,2); %position Y
DOSE(i,j)=MyData((i-1)*Ybin+j,3); %dose-eq in pSv/primary weight
DOSE(i,j)=FS*DOSE(i,j); %dose-Eq em uSv/h, where FS is my conversion factor
ERROR(i,j)=MyData((i-1)*Ybin+j,4);
end
end

figure('color','white');
surf(Y,Z,ERROR,'EdgeColor','none'); %plot ERROR
set(gca, 'ZScale', 'log');
h=colorbar;

-----Mensagem original-----
De: owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-discuss_at_mi.infn.it] Em nome de Masoomeh Yarmohammadi
Enviada em: segunda-feira, 7 de março de 2016 06:49
Para: Vittorio Boccone <dr.vittorio.boccone_at_ieee.org>
Cc: fluka-discuss <fluka-discuss_at_fluka.org>
Assunto: Re: [fluka-discuss]: Statistical error

Dear Vittorio,

Thanks again,

True, I mentioned the error a bit general by writing "Less that 10%". while I was interested to the error in the position of x= -100 +_ 0.5 cm, y= 137 +_ 0.5 cm, z= 549 +_ 0.5 cm, that is the area that I set for VALUE Mesh 1*1*1.

Could you please let me know, if the error and dose data, point by point or bin by bin, is available in a file that I can open and plot it?

I will be grateful if you give your suggestion about the post that I had with the title of "Biasing and Redusing the statistical error".

Best regards

----- Original Message -----
From: "Vittorio Boccone" <dr.vittorio.boccone_at_ieee.org>
Cc: "fluka-discuss" <fluka-discuss_at_fluka.org>
Sent: Sunday, March 6, 2016 5:19:59 PM
Subject: Re: [fluka-discuss]: Statistical error

Dear Masoomeh,
as you compare two different bins with two different bin sizes you will have different errors.

In the las mail you mentioned 2% vs 24%, now 10% vs 24. Your comparison is very qualitative and in order to be more precise you should tell me at which position you are doing the comparison, as the first USRBIN does not contain the second one (5 cm downstream) and the statistic is very poor (just plot a slice of your USRBIN to see the effects…). Still bin will have different sizes and are from different places.

Cartesian binning n. 1 "DEq-Be-WF " , generalized particle n. 240
X coordinate: from -1.6000E+02 to 5.0000E+01 cm, 100 bins ( 2.1000E+00 cm wide)
Y coordinate: from 0.0000E+00 to 2.5000E+02 cm, 100 bins ( 2.5000E+00 cm wide)
Z coordinate: from 5.3500E+02 to 5.4500E+02 cm, 100 bins ( 1.0000E-01 cm wide)

Cartesian binning n. 2 "Value " , generalized particle n. 240
X coordinate: from -1.0050E+02 to -9.9500E+01 cm, 1 bins ( 1.0000E+00 cm wide)
Y coordinate: from 1.3650E+02 to 1.3750E+02 cm, 1 bins ( 1.0000E+00 cm wide)
Z coordinate: from 5.4850E+02 to 5.4950E+02 cm, 1 bins ( 1.0000E+00 cm wide)
Data follow in a matrix A(ix,iy,iz), format (1(5x,1p,10(1x,e11.4)))

From my side there’s absolutely no mismatch, just different bin sizes with different statistics in different places.

Best,
V.

On 06 Mar 2016, at 13:17, Masoomeh Yarmohammadi < myarmohammadi_at_ipm.ir > wrote:

It seems this averaging for flair plotting and reading about 1 bin are not in agreement about the error, less that 10% and 24% respectively. But they are in a good agreement about Does Eq. (Photon scoring) values. Does it correct?!?

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(image/png attachment: USRBIN_Does_Eq_with_biasing_and_e7_input_particles_run-_normalised_to_27e10_to_

Received on Tue Mar 08 2016 - 16:18:34 CET

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