Polarized HD target project  started in April 2005. The first purpose of the project is to investigate the ss̄-quark content of proton and neutron by measuring double polarization asymmetries for the φ meson photoproduction . In addition, the measurement of the double polarization asymmetries provides a good opportunity to present important information to determine the spin-parity of the Θ+ particle. We are developing the polarized HD target for near future LEPS experiments at SPring-8 [3, 4, 5]. We installed a 4He-cryostat, called “Transfer Cryostat (TC)”, above a dilution refrigerator (DR) for picking up and moving the polarized HD target to a storage cryostat (SC) with maintaining high polarization as shown in Fig. 1. The total length of the TC is 5.0 m. The outer-most stainless steel can consists mainly of three separated section of exterior bellows that permit contraction of 3.0 m in total. The TC consists of three concentric stainless steel tubes separated by vacuum. The outer, middle, and inner layers contain LN2, LHe, and LHe, respectively as shown in Fig. 2. The inner layer catches the HD target using a left-hand and right-hand screw system. We can keep the temperature of the polarized HD target below 4.2 K, during the transfer process. There is a superconducting magnet, which produces a magnetic field of about 0.2 Tesla in the HD target region, on the bottom of the middle layer. We constructed a helium recovery line. The HD target building of RCNP and the low temperature cente
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.