Fe K-K- K+K+ 1.8GeV/c p Fe Ξ-Ξ- X-ray Ge-Detector Strong Interaction makes Energy Shift We detect X-ray from Ξ-atom by using Ge-detector for the first time. Energy shift provides information of ΞN interaction. Fe Ξ-Ξ-
K-K- K+K+ 1.8GeV/c p Fe Ξ-Ξ- Ξ-Ξ- X-ray Ge-Detector Strong Interaction makes Energy Shift 1-step,We detect X-ray by using Ge-detector. How to detect X-ray from xi atom is first challenge And 2-step make sure that how much energy shift. Make us information to ΞA interaction Expected Energy Shift (Simulation)
Target SSD SSD measures Ξ track and dE/dx to select slow Ξ so that better S/N ratio will be obtained for stopping Ξ. K-K- K+K+ KURAMA magnet Hyperball-J target K-K-
Thickness ~300um Effective area 6cmx6cm Pitch 80um x 768 strips Read out chip : APV25 128ch readout /1chip Shaping time 50nsec Serial Data Transfer Radiation tolerance checked up to 3x10 14 protons /cm 2 At 10 8 Hz beam, efficiency is accomplished up to 96%
K 計 12 面 768ch SSD Target (inside of cryostat)
Reconstruct pulse height by wave form analysis. We have achieved SNR>10 MIP signal Noise level S/N= =17.0 Reconstruct Hit Timing If 10 7 Hz beam, probability accidental hit is 13.6% Good enough to identify ghost tracks. σ=3.61ns time S/N
SSD has been developed for E03 which detect X-ray from Xi atom for the first time. SSD has been tested at J-PARC K1.8 beamline. We have obtained S/N = 17 and time resolution is 3.61ns which is sufficient for E03 experiment.
a new Ge detector array Hyperball2 ( ε ~4 % for 1 MeV ) can not be used @J-PARC due to high count rate & radiation damage Need new Ge detector array → Need new Ge detector array Lower half of Hyperball-J PWO counter Ge detector Pulse-tube cooler Target Features Radiation-hard Ge detector → Mechanical cooling Fast background suppressor → PWO counter Pulse-shape readout and analysis Adjustable detector geometry Large photo-peak efficiency → ε ~6.1 % @1 MeV with 32 Ge detectors Remotely controlled and monitored