Vol.20,

The estimation of the external quality factor is important for designing coupling devices for the cavities. A new representation of the external quality factor calculations for single-cell cavity coupled to a coaxial transmission line is derived based on analytic analysis and numeric analysis with the help of 3D electromagnetic code, and verified with experimental measurements at room temperature. In logarithmic scale the results for the external quality factor were quasi-linear over the limited range, and the simulated and measured data could be used and extrapolated to the superconducting case. For the unpolished 1.5 GHz 3^rd harmonic superconducting cavity, the discrepancy between the evaluation value and measurement result is less than 25% within an acceptable deviation.

335

In this paper, we report the development of a bunch-by-bunch beam current acquisition system. Through a waveform- reconstruction algorithm, the system realizes high equivalent sampling rate with a relatively low inherent rate. Based on the EPICS environment, information communication with other systems can be achieved. Preliminary test results in commissioning the SSRF storage ring show that the system can reconstruct the beam waveform of single bunch, providing a convenient and reliable method for the top-up operation in the future.

326

In this paper, we report a MATLAB-based GUI tool, bodgui, which integrates functions of lattice editor, linear match, and nonlinear optimization, and visualized tracking functions for beam optics design. A user can switch his/her design procedures one to another. Flexibilities are provided for adjusting or optimizing the lattice settings in commissioning or operation of the accelerators. The algorithm of the linear match and nonlinear optimization, and the GUI windows including the main functions and running status, are presented. The SSRF storage ring was employed as a test lattice. Several optics modes designed and optimized by the GUI tools were used for commissioning the storage ring. Functions of bodgui tool are machine-independent, and it can be well applied to modern light sources being built in other parts of the world.

387

An X-ray microprobe for radiobiological studies was developed which deliver precise doses of radiation to the selected individual cells. The facility used synchrotron radiation as soft X-ray source. A zone plate combining with a pinhole produced a fine probe from bending magnet for single cell irradiating with defined doses. The diameter of microprobe at the target position was about 2 µm by scanning a knife-edge with an AXUV photo diode. The fluxes of soft X-rays at 516.7 eV (2.4 nm) were about 5.4×10⁴ photons/s.100mA measured with the photo diode. The absorbed dose rate for typical yeast cells was about 11.34 Gy/s with the storage current of 100 mA. A preliminary experiment for yeast cells irradiation has shown that the microprobe had a definite biological effect for radiobiological investigations. The soft X-ray microprobe at "water window" region has provided a useful tool for single cell irradiating damage and a capability of individually irradiating a certain numbers of cells each time.

505

In this paper, we study the ability of DNA-PK-deficient (M059J) and -proficient (M059K) cells to undergo the rate of cellular proliferation, cell cycle distribution and apoptosis after 10 Gy X-ray irradiation, and the role of DNA-PK in radiosensitivity. The results showed that M059J cells exhibited hyper-radiosensitivity compared with M059K cells. A strong G2 phase arrest was observed in M059J cells post irradiation. Significant accumulation in the G2 phase in M059J cells was accompanied by apoptosis at 12 h. Altogether, the data suggested that DNA-PK may have two roles in mammalian cells after DNA damage, a role in DNA DSB repair and a second role in DNA-damaged cells to traverse a G2 checkpoint, by which DNA-PK may affect cellular sensitivity to ionizing radiation.

285

Elemental contents of beach rock samples were analyzed using EDXRF. The samples were collected from three locations of Andaman Island. The Al, Ca, K, Fe, Ti, Si, V, Co, Cu, Ba, Zn, Pb, Cd and Mn contents were determined. The geochemical behavior of elements in the region is discussed. The elemental contents of beach rock samples from Andaman Island are much below the values of both earth crust and that of Tamilnadu region. However, content of the biogenic element Ca was the highest of all elements. This is due to the typical beach rock formation.

327

373

¹⁸⁸Re-tin sulfur colloid (TSC) was prepared to compare its biodistribution characteristics with ¹⁸⁸Re-macroaggregates album (MAA) after transhepatic arterial embolization (TAE) in rabbits bearing VX₂ liver tumor. Labeling efficiencies of the ¹⁸⁸Re-TSC and ¹⁸⁸Re-MAA were 99.94%±0.04% and 99.95%±0.03%, respectively, and they were stable for 72 h in human serum. Sintigraphy and biodistribution in 31 rabbits bearing VX₂ liver tumor after transcatherter hepatic arterial injection of the radiopharmaceuticals were performed, and relevant activity accumulated mostly in the tumor. The percentage of the injected dose per gram of wet tissue (%ID/g) of ¹⁸⁸Re-TSC and ¹⁸⁸Re-MAA were calculated. Tumor uptake of ¹⁸⁸Re-TSC at 1 h and 24 h were 24.32%±11.93% and 21.88%±18.29%, and the radioactive ratios of tumor/liver were 70.89±19.58 and 17.42±13.96, respectively. Tumor uptake of ¹⁸⁸Re-MAA at 1 h and 24 h were 38.78%±30.23% and 15.98%±26.64%, and the radioactive ratio of tumor/liver of ¹⁸⁸Re-MAA were 39.71±25.06 and 8.13±4.61, respectively. ¹⁸⁸Re-TSC is a potential radiopharmaceutical for the therapy of tumors.

304

The two-phase flow instabilities observed in through parallel multichannel can be classified into three types, of which only one is intrinsic to parallel multichannel systems. The intrinsic instabilities observed in parallel multichannel system have been studied experimentally. The stable boundary of the flow in such a parallel-channel system are sought, and the nature of inlet flow oscillation in the unstable region has been examined experimentally under various conditions of inlet velocity, heat flux, liquid temperature, cross section of channel and entrance throttling. The results show that parallel multichannel system possess a characteristic oscillation that is quite independent of the magnitude and duration of the initial disturbance, and the stable boundary is influenced by the characteristic frequency of the system as well as by the exit quality when this is low, and upon raising the exit quality and reducing the characteristic frequency, the system increases its instability, and entrance throttling effectively contributes to stabilization of the system.

414

The method of characteristic (MOC) was adopted to analyze the check valve-induced water hammer behaviors for a Parallel Pumps Feedwater System (PPFS) during the alternate startup process. The motion of check valve disc was simulated using inertial valve model. Transient parameters including the pressure oscillation, local flow velocity and slamming of the check valve disc etc. have been obtained. The results showed that severe slamming between the valve disc and valve seat occurred during the alternate startup of parallel pumps. The induced maximum pressure vibration amplitude is up to 5.0 MPa. The scheme of appending a damping torque to slow down the check valve closing speed was also performed to mitigate of water hammer. It has been numerically approved to be an effective approach.

411

A process named gel-casting has been developed for the production of dense UO₂ kernels for the high-temperature gas-cooled reactor. Compared with the sol-gel process, the green microspheres can be got by dispersing the U₃O₈ slurry in gelcasting process, which means that gelcasting is a more facilitative process with less waste in fabricating UO₂ kernels. The UO₂ kernels with the size of 500 µm, O/U≤2.01, density of 10.70 g·cm^-3 were obtained by gel-casting process followed by heat treatment.

274