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LANL-led silicon detector project (FVTX) installed into RHIC this FY, 4.5 cm from beam pipe Increased leakage current in detectors implies somewhat larger radiation doses than were anticipated, profile is different from expected (radiation sources are not entirely from primary collisions) We need to determine the expected lifetime of the detector given the doses that were measured this year We may also want to propose some shielding before next RHIC run (Jan. 2013) These particular sensors have never been fully characterized against dose We would like to irradiate a series of sensors to varying levels and measure how the performance changes versus dose. (I-V in-situ, more detailed measurements offline) Total dose required is ~10 13 Expect that ~1 day of beam time will be sufficient – most of the time needed for setup, putting in/pulling out sensors as they get irradiated.

3 FVTX Project Adds precision tracking to the interaction point Measuring quark + gluon properties in the only laboratory that provides them in unbound state (Quark Gluon Plasma) Constructed FY08-FY11, collected 1 st data FY12 RHIC Provides many beam species: 200 GeV: p+p d+Au, Cu+Cu, Cu+Au, Au+Au, U+U 500 GeV p+p Lower energy everything p+p is highest luminosity FVTX Detector

4 Low multiplicity, but high interaction rate  largest particle dose to detector

5 High multiplicity, but low interaction rate  lowest particle dose to detector

6 500 GeV p+p U+U 200 GeV p+p

7 Shielded Unshielded If tests show it is necessary, permanent shielding might be added to the apparatus at PHENIX during this year’s RHIC shutdown.

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10 Two Arms, Four tracking stations with full azimuthal coverage 75  m pitch strips in radial direction, 3.75° staggered phi strips Radiation length < 2.4%/wedge to minimize multiple scattering Located ~20cm from nominal interaction point Occupany in central Au+Au <3% Initial funding through LANL LDRD, construction funding from DOE 22 mm

11 Installed December 2011