Polarized triplet positronium, formed in the ground state with a polarized slow-e+ beam, is used for an experimental test of CPT (charge-conjugation-parity-time-reversal} invariance. The angular A A A correlation 8 ki Xk2 was measured (where 8 is the positronium spin angular momentum and I k, I & I k2 I & I k3 I are the moments of the three decay y rays}. It is expected to have zero amplitude if CPTis conserved. No effect was found in the experiment at the 2.3% level of uncertainty in the coeScient of the angular correlation. Information gained from a study of the systematic e8'ects, along with straightforward improvements in the apparatus, would allow a 0.1% measurement. Other possible angular correlations using polarized and aligned positronium, including tests of CP invariance, are discussed.

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Following the first experiment on three-body photodisintegration of polarized 3 He utilizing circularly polarized photons from High Intensity Gamma Source (HIγS) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized 3 He target cell made of pyrex glass coated with a thin layer of sol-gel doped with aluminum nitrate nonahydrate has been built in order to reduce the photon beam induced background. The target is based on the technique of spin-exchange optical pumping of hybrid rubidium and potassium and the highest polarization achieved is ∼62% determined from both NMR-AFP and EPR polarimetry. The X parameter is estimated to be ∼ 0.06 and the performance of the target is in good agreement with theoretical predictions. We also present beam test results from this new target cell and the comparison with the GE180 3 He target cell used previously at HIγS. This is the first time that sol-gel coating technique has been used in a polarized 3 He target for nuclear physics experiments.