Radiation protection aspects

1
Radiation protection aspects for the COMPASS
Drell-Yan program
Eduard Feldbaumer CERN/SC-RP Heinz Vincke
CERN/SC-RP
2
Overview

• Radiation ProtectionIssues
• Simulation
• Results
• Conclusion and Outlook

• Area Classification
• Regions of Interest
• Radiation monitors

• Software
• Geometry
• Options
• Magnetic fields

• Prompt dose rate at
• Regions of Interest

3
RP-Regulation

• Area Classification
• Regions of Interest

EHN2 Area classification

• Safety Code F Protection Against Ionizing
  Radiation, CERN, March 1996
• 2) General Safety Instructions Area
  Classification, CERN, December 2006 (EDMS 810149)

4
RP-Regulation

• Area Classification
• Regions of Interest

Tunnel 15 µSv/h
Door PPX 221.1 15 µSv/h
Unshielded Area 15 µSv/h
Barracks 3 µSv/h
Radiation monitors
5
Simulation

• Software
• Geometry
• Options
• Magnetic fields

• FLUKA
• ( Alfredo Ferrari, Paola R. Sala, Alberto Fassò,
  Johannes Ranft )
• A fully integrated particle physics Monte Carlo
  simulation package. FLUKA has many applications
  in high energy experimental physics and
  engineering, shielding, detector and telescope
  design, cosmic ray studies, dosimetry, medical
  physics and radio-biology. from the FLUKA
  webpage (www.fluka.org)
• Simulation of interaction and transport of gt 60
  different particle types.
• Electrons, muons and photons 1keV ? 1000 TeV
• Neutrons thermal energies ? 20 TeV
• Charged hadrons 1keV ? 20 TeV
• SimpleGeo ? solid modeling and visualization
• ( Karl Heinz Buchegger, Chris Theis )
  http//theis.web.cern.ch/theis/simplegeo/

6
Simulation

• Software
• Geometry
• Options
• Magnetic fields

7
Simulation

• Software
• Geometry
• Options
• Magnetic fields

• Beam
• Particle type p -
• Momentum 190 GeV/c and 300 GeV/c
• Intensity 2 x 107 particles/s (108
  particles/spill )
• Energy transport thresholds
• Hadrons 10 MeV
• Neutrons thermal
• e Ekin 100 keV
• ? E 100 keV

8
Simulation

• Software
• Geometry
• Options
• Magnetic fields

• Polarized Target
• Material Ammonia (NH3)
• Length 2 x 30cm
• Density 0.85 g/cm3
• USRBIN Detector
• Fluence ? Effective Dose (deq99c)
• Cartesian Binning
• COMPASS hall Bin size 66 x 106 x 146 cm3
• Tunnel Bin size 21 x 100 x 165 cm3
• Dose rate color plots Bin size 33 x 26 x 29
  cm3

9
Simulation

• Software
• Geometry
• Options
• Magnetic fields

Magnetic fields
Total deflection 30cm at beam dump
Spectrometer Magnet SM1 H 0.9T homogeneous
Spectrometer Magnet SM2 H 1.1T homogeneous
Polarized target magnet H 0.5T solenoid
10
Results

• Prompt Dose Rate at Regions of Interest

Effective Dose Rate Mapping
190 GeV/c
314 cm above ground level (beam height )
300 GeV/c
µSv/h
11
Results

• Prompt Dose Rate at Regions of Interest

Effective Dose Rate Mapping
370 cm downstream from target center (door)
570 cm downstream from target center (tunnel)
µSv/h
12
Results

• Prompt Dose Rate at Regions of Interest

First floor 1.4 µSv/h
Beam level 1.2 µSv/h
Ground level 1.0 µSv/h
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Results

• Prompt Dose Rate at Regions of Interest

Ground level 6.2 µSv/h
14
Results

• Prompt Dose Rate at Regions of Interest

Cable duct 10.9 µSv/h
Door PPX 221.1 19.4 µSv/h
Tunnel 2.2 µSv/h
15
Results

• Prompt Dose Rate at Regions of Interest

Effective dose rates at points of interest
16
Conclusion

• Calculated dose rate levels below limits
• Barracks
• Unshielded area besides beam dump
• Tunnel below COMPASS hall
• Calculated dose rate levels above limits
• Outside at Door PPX 221.1

17
Outlook

• Short term arrangement for hadron runs in 2007
• Temporary marking off the area in front of door
  PPX 221.1
• Locking tunnel passage underneath COMPASS area
• RP measurements during hadron run with moveable
  monitors

18
Outlook

• Long term objective
• Fencing off the area upstream of door PPX 221.1
  and include it in the Interlock System

19
Photos
Door PPX 221.1
Shielding in front of door
20
THE END
21
Photos
Unshielded Area at beam dump