[en] Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined

[en] In the recent years research on surface production H^- ion has been strongly motivated by the need to intense neutral H beams in controlled-fusion and Strategic Defense Initiative applications. Low work function surfaces are of great importance for high-efficiency H^- productions. Cesium-oxide thin films are one of the most important low-work-function materials. The electronic properties of cesium-oxygen-composite thin films deposited on metal (molybdenum) and semiconductor (silicon) substrates are investigated. The surface is characterized using Auger electron spectroscopy (AES), ultraviolet photoelectron spectroscopy (UPS), work function probe and thermal desorption spectroscopy (TDS). Experiments are performed in an ultra-high vacuum (UHV) surface analysis system. Cs/O thin film deposition on Si(100) is accomplished by depositing a monolayer of cesium (using a 20 eV low energy cesium ion gun) and followed by exposure to O₂ gas, which results in a minimum work function of 0.9 eV. Various cesium oxide species are formed during the oxidation of cesiated Si(100), and the minimum work function is due to the formation of a special Cs-O-Si(100) surface structure that is related to the reconstructed Si(100) and Cs₂O₂. The author also studied a 0.5 μm coating on a molybdenum substrate produced by thermal decomposition of Cs₂CO₃ at 920 K. Work function of 0.9 eV is achieved with a sample temperature of 470 K, due to a significant increase of the bulk conductivity. This low work function is maintained for many hours under UHV condition and the sample is completely stable in an atomic hydrogen environment

[en] An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region was first tested in the Brookhaven AGS successfully. CNI Polarimeters were then installed in the AGS and both RHIC rings. The polarimeter consists of ultra-thin carbon targets and silicon strip detectors. The waveform digitizers are used for signal readout, which allows deadtime-less data processing on the fly. Polarimeters are crucial instrumentation for the RHIC spin physics program. This paper summarizes the polarimeter design issues and operation results

[en] TBP Levextrel and cation exchange resins were used to separate RuNO nitrato complexes of different nitric acid concentrations. 7402 quaternary ammonium salt Levextrel was used instead of an anionic exchange resin to separate anionic and neutral complex ions. The results indicated that D₃ and D₄, which can easily be extracted by TBP, were anionic and neutral complex ions

[en] A superconducting microwave ring resonator whose resonant frequency can be tuned is designed and simulated. The structure is a ring resonator directly coupled to two low inductance open loops with Josephson junctions fabricated in a thin film format. The frequency tuning is accomplished by changing the nonlinear equivalent inductance of the Josephson junctions. The designed resonator works with higher Q value than that from other tuning approaches and with a frequency tuning range of 18%

[en] In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Although some depolarization at intrinsic resonances are expected, the level of the depolarization does not agree with a simple model calculation. A spin tracking program is then used to simulate the real polarized proton beam in the AGS. The results show that, due to the linear coupling introduced by a solenoidal 5% partial snake, the polarized beam will be partially depolarized also at the so-called coupling resonance, which is related to the horizontal betatron tune. The synchrotron oscillation also affects the beam polarization to a smaller extent

[en] One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. A beam scrubbing study shows that with a reasonable period of time of running high intensity 112-bunch proton beam, the pressure rise can be reduced, allowing higher beam intensity

[en] In the recent polarized proton runs in the AGS, a 5% partial snake was used successfully to overcome the imperfection depolarizing resonances. Polarized proton beam was accelerated up to the required RHIC injection energy of 25 GeV. However, significant amount of polarization was lost at 0+ν_y, 12+ν_y and 36+ν_y, which is believed to be partially due to the coupling resonances. To overcome the coupling resonance, an energy-jump was generated by rapidly changing the beam circumference using the powerful AGS rf system. It clearly demonstrates that the novel energy-jump method can successfully overcome coupling resonances and weak intrinsic resonances

[en] Two helical partial snakes, one super-conducting (a.k.a cold snake) and one normal conducting (a.k.a warm snake), have preserved the polarization of proton beam up to 65% in the Brookhaven Alternating Gradient Synchrotron (AGS) at the extraction energy from 85% at injection. In order to overcome spin resonances, stronger partial snakes would be required. However, the stronger the partial snake, the more the stable spin direction tilted producing a stronger horizontal intrinsic resonance. The balance between increasing the spin tune gap generated by the snakes and reducing the tilted stable spin direction has to be considered to maintain the polarization. Because the magnetic field of the warm snake has to be a constant, only the cold snake with a maximum 3T magnetic field can be varied to find out the optimum snake strength. This paper presents simulation results by spin tracking with different cold snake magnetic fields. Some experimental data are also analyzed

[en] A method of removing sulfur oxides of H₂S from high temperature gas mixtures (150⁰-1000⁰ C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO₄-- or, in the case of H₂S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (greater than or equal to10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode