Radiation Protection Issues during TI8 Tests

1. Radiation Protection Issues during TI8 Tests Helmut Vincke

2. UJ88 R88 Copper dummy 2 Copper dummy 2 Copper dummy 1 TED TI8 Tests Two total intensities: Low intensity test: 6E13 protons High intensity test: 4E14 protons • Changes compared to tests in 2004: • NO ADDITIONAL SHIELDING downstream TED, all the LHC equipment is installed • What will be the consequences? • Classification as Radiation area required. • Radiological control of material required.

3. High Int. Low Int. Cooling time: 1 week Cooling time: 1 day Cooling time: 12 hours Cooling time: 4 hours Dose rate levels after test 1.5E+02 7.0E+01 • Calculation parameters used for the FLUKA simulation: • 12 hours irradiation time (conservative approach) • 5 different cooling times • In LHC no beam components are considered 3.2E+01 1.5E+01 7.0E+00 3.2E+00 1.5E+00 7.0E-01 3.2E-01 1.5E-01 7.0E-02 3.2E-02 1.5E-02 7.0E-03 3.2E-03 1.5E-03 7.0E-04 3.2E-04 1.5E-04 7.0E-05 3.2E-05 1.5E-05 Cooling time: 1 hour Max dose rate in LHC after high intensity test 1 hour cooling50 uSv/h 4 hours cooling50 uSv/h 12 hours cooling 30 uSv/h 1 day cooling20 uSv/h 1 week cooling0.1 uSv/h uSv/h

4. After first few hours of cooldown 1.5 days of cooldown Supervised Area* Personal dosimeter obligatory * New classification scheme, for transient access Radiological consequences of the tests (based on activation of LHC concrete walls) UJ88 and R88 ( from UJ88 40 m in direction Point 1) will be declared as radiation areas after first (low intensity) test: Low intensity test High intensity test First few hours after test Up to 1.5 days after test (15 uSv/h) Controlled Radiation Area Personal and active dosimeter obligatory Job and dose planning required Transport under these conditions allowed under RP supervision Before access radiation survey has to be done (time requirement: 1 hour) • All material must be controlled before removed from the (radiation) area Take care: radiation contribution of other unknown material of LHC installation could not be considered in calculation. Real activation levels have to be found out during low intensity test.

5. Precautions to be taken due to unknown material During first test we need to monitor radiation carefully to get information for high intensity test. We need to take some cool down breaks during beam operation to compare real dose rates with expected dose rates. We know that dose rate coming from the walls in R88 should not be higher than 7 uSv/h after a cool down of one hour. If we see higher values  radiation contribution of installed LHC equipment is significant. Details of procedure will be worked out in cooperation with AB. In case we get too high radiation levels  local shielding of hot components. Worst (unlikely) case: access to area needs to be temporarily blocked

6. Radiation Monitors used during and after the TI8 tests • IG5 monitors installed at access doors in order to measure prompt radiation during test. Monitors will be in the interlock of the machine • PMI monitors are installed close to TED, in UJ88 and in R88 in order to measure dose rate originating from material activation • TLDs or/and HLD dosimeters might be installed along beam line in order to measure dose to material during test