Residual dose rate at the muon pits dose
- Slides: 6
Residual dose rate at the muon pits & dose rate downstream of the hadron stopper during operation of SBLNF Heinz Vincke, DGS/RP, 1 SBLNF meeting 5. 12. 2012
some parameters � Beam momentum 100 Ge. V/c � Beam intensity 4. 5× 1013 p/3. 6 s 200 k. W � Irradiation � Density 2 profile: 180 days of continues beam of Moraine 1. 9 gcm-3
Ambient dose equivalent rate at muon pits (1 week cooling) - preliminary results More CPU time/MC–techniques needed to improve statistics preliminary results g n i t ee tm 3 2 nd muon pit Decay tunnel After 1 week of decay: Hadron stop Pre Hadron stop te sen 1 st muon pit h t d in s e la 1 st muon pit: • A few hundred u. Sv/h inside • ~30 u. Sv/h at ‘border’ to iron 2 nd muon pit: OK
Ambient dose equivalent rate in the muon pits (final results) C-core of HS 4 … same conclusion as before: (after 1 week of decay) 2 nd muon pit Fe of HS End of decay tunnel 1 st muon pit Concrete shielding Fe of HS H*10 (after 1 week of decay) 1 st muon pit: • A few hundred u. Sv/h inside • ~30 u. Sv/h at ‘border’ to iron 2 nd muon pit: OK
Dose rate during beam Position of EHN 1? 100 Ge. V muon ranged out at 320 m (see M. Calviani’s talk from 19. 10. 2012) …. at a distance of ~280 m (from target) dose rate < 1 u. Sv/h EHN 1 has ‘permanent workplaces’ with an ambient dose rate limit of 3 u. Sv/h. 5
Dose rate during beam (100 Ge. V/c, 4. 5 E 13 ppp/3. 6 s->200 k. W) z- distance from target 3 u. Sv/h 1 u. Sv/h … proposal to use (at least) the 1 u. Sv/h limit: • to have a safety factor • to allow a possible increase to 300 k. W without RP consequences for EHN 1 (radiological re-classification, restricted access in EHN 1, etc). 6 distance from target 1 u. Sv/h limit 3 u. Sv/h limit (Hadron stopper distance from centerline starts at 100 m) [in cm] 120 m - 140 m - 160 m - 180 m- 200 m - 220 m - 240 m - 260 m 1350 1150 910 810 680 610 500 1060 860 735 670 610 510 400
