Introduction From a neutron flux (> 20 MeV), with the Leaching model (Lessard) based on SBMS (Tables 1 and 2): we can obtain soil activation in pCi/L (assuming soil interaction parameter of 60 cm), and vice versa. The models in Booster that I have used here are the ones built my 2012 SULI student Allison Matus for B6 beam dump and D6 septum. The former probably has more shielding than the E7 magnet whereas the latter has less shielding than the E7 magnet. Nevertheless, the result for the same contour are similar (probably within 50 cm or so).

2.278 x x x x x Beam Dump (B6) Beam Direction Soil Neutron fluxes in cm -2 per incident proton  Sky direction points out of page Beam Dump of Booster x cm-600 cm cm

Beam Direction Septum 0600 cm-600 cm cm Soil Concrete  Sky direction points out of page Neutron fluxes in cm -2 per incident proton Extraction Septum of Booster x x x x x x 10 -7

Comparison using the soil sample in E7 Cap Soil sample(s) placed at E7 at beam height (eg. at 90  ) for 4 weeks with intensity of 2  protons every 3.9 seconds have resulted in  24.4 pCi/L ( 22 Na) or 257 pCi/L ( 3 H) at 90    3.1  10  8 neutrons/cm 2 (using the afore-mentioned leaching model) In MCNPX simulation at beam height, with the B6 model (the one with more shielding)   8  10  7 neutrons/cm 2 near tunnel wall  below the floor   5  10  8 neutrons/cm 2 (though inappropriate comparison)  26 times more than the above soil sample has shown If we assume the radiochemistry done for the soil sample and our assumption of the location of the bottle are perfect, then the assumption of 100% loss of 2  protons, the leaching model and/or MCNPX simulation are all too “conservative” (or exaggerated).

Boundaries 5 months of running with loss intensity of 4  protons every 4 seconds  Using the limit of 1000 pCi/L ( 3 H) (and 60 cm as soil interaction length)   1.17  10  8 neutrons/cm 2 (using the leaching model) { Previously, if I used 20 pCi/L ( 22 Na) and 40 cm as soil interaction length), it was ~1.6  10  9 /cm 2. } With the contours underneath the floor and at beam height, I can set boundaries, after we agree on the parameters (such as loss intensity and duration ….)

1.17 x Beam Dump (B6) Beam Direction Soil Neutron fluxes in cm -2 per incident proton  Sky direction points out of page Beam Dump of Booster cm-600 cm cm Underneath

1.17 x Beam Dump (B6) Beam Direction Soil Neutron fluxes in cm -2 per incident proton  Sky direction points out of page Beam Dump of Booster cm-600 cm cm Beam height

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2.278 x x x x x Beam Dump (B6) Beam Direction Soil Neutron fluxes in cm -2 per incident proton  Sky direction points out of page Beam Dump of Booster x cm-600 cm cm Beam height