Vol.14,

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The newly developed Digital Beam Position Monitor (DBPM) system is introduced. The DBPM system differs with the conventional beam position monitor system in the use of DSP chips and the digital signal processing technology. It can be programmed on-line to select operation modes through EPICS control panel, and to measure various parameters of the third generation synchrotron radiation facility. This DBPM system can be used in the pre-injector LINAC, the transfer lines, the booster synchrotron and the storage ring. The electronic parameters of the DBPM system itself have been measured also.

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²³⁰Pa was produced through the ²³²Th(p,3n)²³⁰Pa reaction in the irradiated ThO₂ powder targets with 35 MeV proton beam. Pa was radiochemically separated from ThO₂ and other reaction products, and then thin sources of 230Pa→β−230U were prepared. The polyethylene-terephthalate (lavsan) films were selected as solid track detector searching for the cluster activity of ²³⁰U. The gamma activity of ²³⁰Pa in the sources was measured using a HPGe detector. The lavsan films were etched in NaOH solution and the etched films were scanned under an optical microscope. The exotic nuclear decay of ²³⁰U by emission of ²²Ne was observed. A branching ratio relative to α decay was deduced, B =λ_Ne/λα = (1.3±0.8)×10^-14 for ²²Ne emission from ²³⁰U.

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The Monte Carlo simulation with the energetics described by the embedded atom method has been employed to mainly study physical behaviors of boron atoms during relaxation of the Ni₃Al-x at.% B grain boundary. During relaxation of impure Ni₃Al grain boundaries, we suggest that for different types of impure atoms(Mg, B, Cr and Zr atoms etc.), as the segregating species, they have the different behaviors, but as the inducing species, they have the same behaviors, i.e. they all induce Ni atoms to substitute Al atoms. Calculations show that at the equilibrium, when x(the B bulk concentration) increases from 0.1 to 0.9 , the peak concentration of B increases, correspondently, the peak concentration of Ni maximizes but the valley concentration of Al minimizes, at x = 0.5. The calculations also show the approximate saturation of Ni at the grain boundary at x = 0.5.

300

The method to synthesize a high affinity muscarinic receptor antagonist (R,S)I-QNB[(R)-(-)-1-azabicyclo [2,2,2]oct-3-yl-(S)-(+)-α-hydroxy-α-(4-[127I]iodophenyl)-α-phenyl acetate] from 4-nitrobenzophenone with improvement compared to literatures was reported in this article. IR, MS and ¹HNMR characterized the final product. (R,S)¹³¹I-QNB was prepared using Cu(I) assisted iodine exchange labeling, and showed by TLC that the radiolabeling yield(RLY) was over 80%, and radiochemical purity(RCP) was over 95%. Stability of the labeled compound was also determined. It was found that (R,S)¹³¹I-QNB dried by nitrogen blowing can stay at 4-10℃ for a week without change of RCP.

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Superconducting TF and PF coils have been measured in SULTAN test facility. Segregated copper strands are included in four NbTi CICC and this is a technical innovation. Two AC losses measurement methods, calorimetric and electromagnetic methods, have been used in the experiments, and a broad frequency range (from 0.05 Hz to 6 Hz) is covered in sample test. The purpose of this experiment was to investigate AC losses of TF and PF CICC conductor including segregated copper and to check the design of PF and TF CICC coated with different resistive barriers (Pb–30Sn-2Sb and Ni plating on NbTi strands).

240

The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations between microwave absorption efficiency and plasma chamber structure and thickness of the microwave introduction window are studied. The microwave absorption efficiency reaches to 100% when plasma chamber is 100mm long and the window thickness is 30mm. The microwave absorption efficiency as a function of pressure is also presented.

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The precision of results obtained from the ¹⁰⁹Cd K XRF in vivo measurement system of bone lead for obese subjects with high BMI (body mass index) was poor. The main factor affecting the precision was the distance between tibia and detector. Compared with the standard phantom, a large phantom was used to simulate the obese subject in the measurements at different distances to the detector. The counts of Compton scattering increased highly because of the tissue overlying and surrounding tibia of the obese subject. When the distance between leg and detector was too small, the instrument would produce the distorted x-ray spectra, so that the obtained data were inaccurate. In order to ensure good measurement precision and accuracy, the distance between leg and detector should be maintained at 25 mm during the counting period. Meanwhile, the dead time displayed instantly on the instrument should be controlled to around 30%.

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