RE: Can not follow the results of example in FLUKA web

From: Mary Chin <Mary.Chin_at_cern.ch>
Date: Thu, 5 May 2011 12:28:21 +0200

Hai Hantao,

First of all, is there any particular reason why you prefer FLUKA2008.3d?
Otherwise, you are strongly encourage to upgrade to the latest release.

Your eyes are better than mine, because I can hardly read any text from
the low-resolution image (Figure 1 on the web). So I start with the value
you provided: 3.2432E-5 GeV/cm^3 per electron, which gives
3.2432e-05* 1.6e-7/2.64 * 8.7e-10*1.7/760 *1e6 microGy per electron, and
therefore
3.2432e-05* 1.6e-7/2.64 * 8.7e-10*1.7/760 *1e6 / (1.6e-19*1e3/7.39/3600)
= 6.3602e+02 microGy per mA

The numbers 8.7e-10 torr, 1.7 multiplicative factor and 7.39 hour originate
from Esposito's paper. I calculated the current from the 'beam life'.
The number of electrons (1.66e+20) cancels out therefore I do not need the
actual number for the calculation.

I know 636 != 1510 but I'm happy to get the correct order of magnitude.
This is a quick estimation without uncertainty analysis.

Next, if I run the input file myself, I get the peak in FirstTLD
= 8.0744e-05 GeV/cm^3. Then,
8.0744e-05* 1.6e-7/2.64 * 8.7e-10*1.7/760 *1e6 / (1.6e-19*1e3/7.39/3600)
= 1.5834e+03 microGy per mA

Doesn't this look even better!

:) mary

> -----Original Message-----
> From: owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-
> discuss_at_mi.infn.it] On Behalf Of Hantao Jing
> Sent: 02 May 2011 12:53
> To: fluka-discuss_at_fluka.org
> Subject: Can not follow the results of example in FLUKA web
>=20
> Dear FLUKA experts,
> I want to follow the results of "Example of dose
> calculation using FLUKA in context of an experiment performed at the
> INFN Laboratori Nazionali di Frascati (LNF) to calculate the dose
> produced by gas bremsstrahlung at the ADONE electron-positron storage
> ring (http://fluka.php?id=3Dexamples&sub=3Dexample2). Therefore,
> I download the input file of gasbrem.inp and run it with the following
> command:
> $FLUPRO/flutil/rfluka -N0 -M10 gasbresm&
> The FLUKA version is fluka2008.3d. Then, the results is obtained by
> usbsuw program:
> 1
> Cartesian binning n. 1 "First " , generalized particle n.
> 208
> X coordinate: from -1.4265E+00 to 1.4265E+00 cm, 9 bins (
> 3.1700E-01 cm wide)
> Y coordinate: from -1.4265E+00 to 1.4265E+00 cm, 9 bins (
> 3.1700E-01 cm wide)
> Z coordinate: from 2.1170E+02 to 2.1179E+02 cm, 1 bins (
> 8.8900E-02 cm wide)
> Data follow in a matrix A(ix,iy,iz), format
> (1(5x,1p,10(1x,e11.4)))
>=20
> accurate deposition along the tracks requested
> 4.2517E-06 5.2404E-06 6.3007E-06 7.1450E-06 7.4702E-06
> 7.0821E-06 6.1108E-06 5.3350E-06 4.0904E-06 5.3021E-06
> 6.9242E-06 9.0744E-06 1.0929E-05 1.1615E-05 1.0940E-05
> 9.1046E-06 7.1023E-06 5.1818E-06 6.3525E-06 9.0383E-06
> 1.3133E-05 1.7996E-05 2.1170E-05 1.8402E-05 1.3152E-05
> 9.3588E-06 6.0706E-06 7.1982E-06 1.1318E-05 1.8818E-05
> 3.2732E-05 4.3062E-05 3.2938E-05 1.8867E-05 1.1458E-05
> 7.2968E-06 7.8073E-06 1.2400E-05 2.2234E-05 4.8802E-05
> 8.0744E-05 4.8871E-05 2.1742E-05 1.2263E-05 7.6456E-06
> 7.3533E-06 1.1392E-05 1.8975E-05 3.2817E-05 4.3732E-05
> 3.2604E-05 1.9071E-05 1.1172E-05 7.1886E-06 6.3338E-06
> 9.0320E-06 1.3372E-05 1.8669E-05 2.0860E-05 1.8591E-05
> 1.3316E-05 9.1300E-06 6.4121E-06 5.2601E-06 7.0427E-06
> 9.0760E-06 1.1276E-05 1.1949E-05 1.0938E-05 9.3113E-06
> 6.9504E-06 5.2326E-06 4.1439E-06 5.3743E-06 6.1863E-06
> 7.0768E-06 7.4555E-06 7.0991E-06 6.3421E-06 5.1644E-06
> 4.1256E-06
>=20
> Percentage errors follow in a matrix A(ix,iy,iz), format
> (1(5x,1p,10(1x,e11.4)))
>=20
> 2.2964E+00 1.6554E+00 1.6183E+00 1.2396E+00 1.7084E+00
> 1.4425E+00 1.8012E+00 1.9117E+00 2.0120E+00 1.0476E+00
> 1.3214E+00 1.6861E+00 7.5966E-01 8.8235E-01 1.2887E+00
> 1.2867E+00 1.5561E+00 1.8029E+00 1.5129E+00 9.5464E-01
> 9.7567E-01 9.8942E-01 7.1862E-01 1.4051E+00 1.2920E+00
> 9.1504E-01 1.7898E+00 1.2718E+00 1.0728E+00 1.2945E+00
> 8.4007E-01 4.0738E-01 7.4852E-01 1.0894E+00 1.2322E+00
> 1.2961E+00 1.7421E+00 1.4518E+00 6.7243E-01 4.4831E-01
> 5.5289E-01 5.1126E-01 6.5050E-01 8.1552E-01 1.4150E+00
> 7.6730E-01 1.1712E+00 9.0391E-01 5.7001E-01 6.3703E-01
> 6.6893E-01 1.0929E+00 4.7263E-01 9.7158E-01 1.4058E+00
> 9.7550E-01 8.3666E-01 9.6425E-01 9.5974E-01 1.0777E+00
> 1.1423E+00 1.1156E+00 1.4287E+00 1.4051E+00 1.4547E+00
> 1.5493E+00 1.3439E+00 1.5610E+00 7.8682E-01 1.1736E+00
> 1.6611E+00 1.9968E+00 1.9193E+00 2.2169E+00 1.6782E+00
> 1.2294E+00 1.6989E+00 2.0874E+00 8.2612E-01 1.8507E+00
> 2.0287E+00
>=20
> From the results, we can find the large difference with Figure 1 at
> web. Why the difference exist for two results?
>=20
> On the other hand, I use the results from Figure 1 to calculate
> the
> dose rate of First dosemeter:
> the maximum value in Figure 1 is about 3.2432E-5 GeV/cm^3;
> the factor to coverse to Gy unit: 1.6E-7/2.64;
> the number of electrons for 1 mA is about 6.24E15 e/s;
> the pressure ratio of atmospheric pressure to the operating
> pressure of the machine (133.0 nPa =3D 10^--9 torr) is about 7.59E11;
> So the dose rate in uGy/mA is 3.2432E-5 * (1.6E-7/2.64) * 6.24E15 *
> 10E6
> / 7.59E11 =3D 0.0159436 uGy/mA;
> But the results in TABLE 3 in NIMB 88(1994) 345 is 1510 uGy/mA, what is
> wrong with my calculated results?
> Thank you very much !
>=20
>=20
>=20
> Hantao Jing
>=20
> 2011-5-2
Received on Thu May 05 2011 - 12:58:39 CEST

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