Stereo Collab Meeting | CEA Saclay July-2015 Conclusions

Stereo Collab Meeting | CEA Saclay July-2015 CONFIGURATION OF ILL CASEMATE Soft iron + B4C protection designed. Missing fire protection D19 lead wall. To be installed in November. Front wall under fabrication To be installed this summer. IN20 wall under design/validation

Stereo Collab Meeting | CEA Saclay July-2015 Last piece of external shielding, IN20, comes in during the winter stop  Be ready for a last background Xcheck as soon as the reactor restarts. Must be able to fill the detector during the first cycle of 2016 as soon as we are ready  Submit the ASN file in October 2015

Stereo Collab Meeting | CEA Saclay July-2015  Design of the movable detector with its shielding is completed  Total estimated mass of 93t compatible with lifting capacity of 120 t.  Displacement secured by rails and rotation point – under study.  Need to work on air pressure supply.  Interface with floor liner.

Stereo Collab Meeting | CEA Saclay July-2015 Lead, Polyethylene and mumetal shielding Launch purchase procedure this month for delivery of shielding support structure in November. Design to be fixed in the next few days  Need to validate final size of aperture for tubes and cables Must make sure that the delivery date of lead shielding doesn’t induce extra delay

Stereo Collab Meeting | CEA Saclay July-2015 Calibration system around the detector is under test. CALIBRATION Calibration constant from source on the side Requires good tuning of simulation to determine the most probable energy deposition

Stereo Collab Meeting | CEA Saclay July-2015 CALIBRATION Even more compton from sources underneath Nice idea to use Fe capture line to add one calibration point at high energy.

Stereo Collab Meeting | CEA Saclay July-2015 CALIBRATION Z dependence best determined from Na22 on the side of the detector vessel

Stereo Collab Meeting | CEA Saclay July-2015 CALIBRATION Calibration of light leakage possible

Stereo Collab Meeting | CEA Saclay July-2015 INNER DETECTOR X2 X6 « Central » frame « External » frame Finalized vessel and buffer mechanics Working on top lid flanges and calibration pipes Tender process finished, signing the order this month! Buffer and PMT mechanics to be produced at MPIK

Stereo Collab Meeting | CEA Saclay July-2015 INSTALLATION PLANING Detector vesel on site Detector filled

Stereo Collab Meeting | CEA Saclay July-2015 PMTS Stereo PMTs to be tested in September Using faraday laboratory un MPIK  Gain curve  Dark noise  Gain stability  Incident angle dependence might be a useful info… we should be able to measure it if necessary

Stereo Collab Meeting | CEA Saclay July-2015 LIQUID SCINTILLATOR LAB 75%, PXE 20%, DIN 5% Gd 0.2% + 1% THF Purified for better attenuation length Stereo samples still stable after 2 years Filling system for target liquid ready Working on filling system for GC Updated safety data sheets Need to finalize choice of liquid sensors

Stereo Collab Meeting | CEA Saclay July-2015 MUON VETO New prototype under test with new acquisition Optimized trigger mapping to reduce sensitivity to high E gammas. Demonstrate high and stable efficiency Requires mumetal protection around the veto vessel. Launch order next week for delivery in October Trigger pattern

Stereo Collab Meeting | CEA Saclay July-2015 MITIGATION OF IN20 STRAY FIELD  New PMT tests performed at LPSC  High sensitivity to transverse field well corrected by the mumetal tube  Updated specification of ~0.6 G external field for PMTs inside mumetal cylinder  Confirm with shorter mumetal tube?

Stereo Collab Meeting | CEA Saclay July-2015 MITIGATION OF IN20 STRAY FIELD Maentouch & Comsol simulations validate the soft iron + mumetal design <0.2 G expected, including effect of 2 mm gaps. Design with 10 mm soft iron mm mumetal around det, 1mm around veto.

Stereo Collab Meeting | CEA Saclay July-2015 ON SITE BACKGROUND MEASUREMENTS IN20 magnet is back on site Mapping of the Stereo area sheduled on July 19 – Aug 6.

Stereo Collab Meeting | CEA Saclay July-2015 Extensive mapping of the Stereo area using Ge and NaI detectors Data taken with different configurations of D19 and IN20. Extra protection of 10 cm of lead on the D19 side and 15 cm on the IN20 side required to keep margin w.r.t. the specification on accidental background. ON SITE BACKGROUND MEASUREMENTS

Stereo Collab Meeting | CEA Saclay July-2015  Independent fast neutron measurements seem not compatible with each other.  Data analysis must be coupled with a simulation of the detector.  Flux measurements performed in H13 to be compared with MCNPX simulations.  Decision on a new measurement campaign requires more analysis of current data. ON SITE BACKGROUND MEASUREMENTS

Stereo Collab Meeting | CEA Saclay July-2015 SIMULATION New sandwich geometry implemented 5% light leaks on average:  No big impact on energy resolution  Impact on energy scale, shape uncertainty? More realistic liquid properties defined  Have to deal with different calibration constants in TG and GC.

Stereo Collab Meeting | CEA Saclay July-2015 SIMULATION Need a decision on segmented GC or not. Will investigate 4 extra plates production either at Saclay or at the company

Stereo Collab Meeting | CEA Saclay July-2015 INNER DETECTOR PROTOTYPE Uniformity of the response is within specifications Larger deviations observed when the diffuser is against an acrylic wall, dominated by local effects. Compatible results from source scans outside the vessel Difficult tuning of the simulation because of compton evts on surrounding material

Stereo Collab Meeting | CEA Saclay July-2015 ELECTRONIC - DAQ Lot a items already operational Request for clearer specifications on recorded data type of sensors  Will create a dedicated working group to converge on this. 120 Gb/day…