Vol.19,

Phase I commissioning of the SSRF storage ring at 3.0 GeV was ended with encouraging results. Distortions and calibrations of the linear optics during the storage ring commissioning are discussed in this paper. The calibration procedure has reduced sextupole-additional focusing effects by minimizing closed orbit deviation and corrected quadrupole magnetic coefficients with the linear optics from closed orbit (LOCO) technique. After fitting the closed orbit response matrix, linear optics of the storage ring is substantially corrected, and the measured parameters agree well with the design. Four optics modes were commissioned, and relevant machine physics studies were carried out. Their results are summarized.

448

As a natural character of high gain free electron laser (FEL), harmonic radiation is regarded as the natural extensions to short wavelengths. In high gain harmonic generation (HGHG) scheme, harmonic evolution may be attributed to the initial harmonic bunching, self amplification of the harmonic radiation, electron beam strongly bunched by the fundamental radiation, the faster longitudinal dynamics and the fundamental synchrotron oscillation. It is more complex than harmonic evolution in other FEL schemes. In this paper, via theoretical analyses and three dimensional simulations, a general description of different aspects of harmonic evolution in the HGHG process is presented.

683

Multi-bunch instabilities degrade beam quality through increased beam emittance, energy spread and even cause beam loss. A feedback system is used to suppress multi-bunch instabilities associated with resistive wall of the beam ducts, cavity-like structures, and trapped ions. A digital TFS (Transverse Feedback System) is in construction at the SSRF (Shanghai Synchrotron Radiation Facility), which is based on the latest generation of FPGA (Field Programmable Gate Array) processor. Before we get such FPGA digital board, investigation and simulation of the front-end were done in the first place. The signal flow was analyzed by SystemView. Construction and optimization of the entire system is our next goal.

463

In this paper we discuss neural network-based matrix effect correction in energy dispersive X-ray fluorescence (EDXRF) analysis, with detailed algorithm to classify the samples. The method can correct the matrix effect effectively through classifying the samples automatically, and influence of X-ray absorption and enhancement by major elements of the samples is reduced. Experiments for the complex matrix effect correction in EDXRF analysis of samples in Pangang showed improved accuracy of the elemental analysis result.

651

The China Advanced Research Reactor (CARR) is scheduled to be operated in the autumn of 2008. In this paper, we report preparations for installing the neutron radiography instrument (NRI) and for utilizing it efficiently. The 2-D relative neutron intensity profiles for the water-vapor two-phase flow inside the tube were obtained using the MCNP code without influence of γ-ray and electronic-noise. The MCNP simulation of the 2-D neutron intensity profile for the water-vapor two-phase flow was demonstrated. The simulated 2-D neutron intensity profiles could be used as the benchmark data base by calibrating part of the data measured by the CARR-NRI. The 3-D objective images allow us to understand the flow pattern more clearly and it is reconstructed using the MATLAB through the threshold transformation techniques. And thus it is concluded that the MCNP code and the MATLAB are very useful for constructing the benchmark data base for the investigation of the water-vapor two-phase flow using the CARR-NRI.

587

The study was to investigate the role of pinhole single photon emission computed tomography (SPECT), the human pulmonary adenocarcinoma bone-seeking metastasis cell line SPC-A-1BM was used. These cells form typical osteolytic bone metastases when inoculated into the arterial circulation of NIH-Beige-Nude-XD (BNX) mice via the left ventricle. In order to evaluate the irradiation impact of ^99mTc-MDP versus X-ray on cells growth, we used six groups of SPC-A-1BM cells in our imaging scheme and irradiated by various doses of ^99mTc-MDP (37, 74, 111, 370, 740 MBq) and X-ray(40 kV, 2 mA, 6 s) respectively. The cell's number of each group was well recorded in different exposure time (4, 8, 12, 24, 48, 72, 96 hours) . After that, SPC-A-1BM cells (1×106) were inoculated into the mice via left ventricle. We compared the results obtained with those different doses of ^99mTc-MDP using pinhole SPECT and conventional X-ray skeletal surveys. The data show that the cell-survival number of 111 MBq group has insignificant difference with that of X-ray and the dose is adequate to have an ideal image. Besides, it is important that the chromosome of the cells in the group of 111 MBq showed no irradiation-related damages in our test. These results implied that ^99mTc-MDP pinhole SPECT may provide another way other than conventional X-ray skeletal surveys in detecting bone metastasis of pulmonary adenocarcinoma in BNX mice.

382

A new compact gamma camera for small object imaging has been developed. It consists of a pixelized Nal(Tl) scintillator array coupled to a position sensitive photomultiplier tube (Hamamatsu R2486) with a parallel-hole lead collimator. The compact camera has better spatial resolution than Anger camera. The average value of intrinsic spatial resolutions is 2.3 mm (FWHM). The overall spatial resolution (FWHM) is 3, 5 and 6 mm at 0, 2.5 and 3 mm SCD (source-to-collimator distance), respectively. The phantom studies with the compact camera have demonstrated that parallel-hole collimator gamma camera is a practical technique for nuclear medicine application.

402

This paper presents the results of natural radioactivity measured for the soil of Qena using gamma-ray spectrometry at ZSR, Hanover University, Germany. Soil samples of radioactive concentrations of ²³⁸U-series (²³⁴Th, ²¹⁴Pb, and ²¹⁴Bi), ²³²Th-series (²²⁸Ac, ²¹²Pb, and ²⁰⁸Tl) and ⁴⁰K were analyzed. Three objectives were set: (1) activity levels by surface soil sampling at 0~30 cm depth, (2) dose rates of gamma radiation, radium equivalent, index hazard, and effective dose, and (3) ambient dose rates.

497

Using the grey correlation analysis, it can be concluded that the reactor pressure vessel wall temperature has the strongest effect on the passive residual heat removal system in HTR (High Temperature gas-cooled Reactor), the chimney height takes the second place, and the influence of inlet air temperature of the chimney is the least. This conclusion is the same as that analyzed by the traditional method. According to the grey model theory, the GM(1,1) and GM(1, 3) model are built based on the inlet air temperature of chimney, pressure vessel temperature and the chimney height. Then the effect of three factors on the heat removal power is studied in this paper. The model plays an important role on data prediction, and is a new method for studying the heat removal power. The method can provide a new theoretical analysis to the passive residual heat removal system of HTR.

614

The second Egyptian research reactor ET-RR-2 went critical on the 27th of November 1997. The National Center of Nuclear Safety and Radiation Control (NCNSRC) has the responsibility of the evaluation and assessment of the safety of this reactor. The purpose of this paper is to present an approach to optimization of the fuel element plate. For an efficient search through the solution space we use a multi objective genetic algorithm which allows us to identify a set of Pareto optimal solutions providing the decision maker with the complete spectrum of optimal solutions with respect to the various targets. The aim of this paper is to propose a new approach for optimizing the fuel element plate in the reactor. The fuel element plate is designed with a view to improve reliability and lifetime and it is one of the most important elements during the shut down. In this present paper, we present a conceptual design approach for fuel element plate, in conjunction with a genetic algorithm to obtain a fuel plate that maximizes a fitness value to optimize the safety design of the fuel plate.

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