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.

We have observed a linear pressure dependence of longitudinal relaxation time T 1 at 4.2 and 295 K in gaseous 3 He cells made of either bare Pyrex glass or Cs-or Rb-coated Pyrex due to paramagnetic sites in the cell wall. The paramagnetic wall relaxation is previously thought to be independent of 3 He pressure. We develop a model to interpret the observed wall relaxation by taking into account the diffusion process, and our model gives a good description of the data.

Abstract. We present a summary of a recent workshop held at Duke University on Partonic Transverse Momentum in Hadrons: Quark Spin-Orbit Correlations and Quark-Gluon Interactions. The transversemomentum-dependent parton distribution functions (TMDs), parton-to-hadron fragmentation functions, and multi-parton correlation functions, were discussed extensively at the Duke workshop. In this paper, we summarize first the theoretical issues concerning the study of partonic structure of hadrons at a future electron-ion collider (EIC) with emphasis on the TMDs. We then present simulation results on experimental studies of TMDs through measurements of single-spin asymmetries (SSA) from semi-inclusive deep inelastic scattering (SIDIS) processes with an EIC, and discuss the requirement of the detector for SIDIS measurements. The dynamics of parton correlations in the nucleon is further explored via a study of SSA in D (D) production at large transverse momenta with the aim of accessing the unexplored tri-gluon correlation functions. The workshop participants identified the SSA measurements in SIDIS as a golden program to study TMDs in both the sea and valence quark regions and to study the role of gluons, with the Sivers asymmetry measurements as examples. Such measurements will lead to major advancement in our understanding of TMDs in the valence quark region, and more importantly also allow for the investigation of TMDs in the unexplored sea quark region along with a study of their evolution.