Vol.19,

The Shanghai Synchrotron Radiation Facility (SSRF), a third generation light source, comprises a 3.5GeV electron storage ring, a full energy booster, a 150 MeV linac, and seven beamlines in Phase I of the project. Beginning at the end of 2004 with a groundbreaking ceremony, the accelerators were installed in ten months from November 2006, and were successfully tested and commissioned in the past a couple of months. On December 21, 2007, storing electron beams in the storage ring was realized, and the first synchrotron radiations were observed three days later on the front-end of Beamline BL16B of the facility. Now, it runs 3 GeV 100 mA beams with a lifetime of 8~10 hours. Meanwhile, construction of the first seven beamlines (five ID beamlines and two bending magnet beamlines) is progressing on schedule.

508

By choosing parameters in the modulator, the dispersive section and the seed laser, the spatial bunching of the electron beam can be correlated to the n-th harmonic of the radiator radiation, instead of the fundamental radiation in conventional high-gain harmonic generation (HGHG). Thus, the radiator undulator is operated at high harmonic mode. In this paper, the possibility of harmonic operation of Shanghai deep ultraviolet (SDUV) free electron laser (FEL) is studied. Discussions on the principle of harmonic operation, the simulation code development, the simulation results, and the proposed experimental procedure for verification of harmonic operation at the SDUV FEL are also presented.

403

In order to obtain Pleurotus ferulae with high temperature tolerance, mycelium mono-cells of wild type strain ACK was treated by nitrogen ion (5~30 keV, 1.5×10¹⁵~1.5×10¹⁶ cm^-2) implantation, and mutant CGMCC1762 was selected through auxotrophy screening method, which was Lys, VB6 auxotrophy stress with high temperature. We found that during riper period the surface layer mycelium of the mutant was not aging neither grew tegument even above 30°C. The mycelium endurable temperature of the mutant was increased 7°C compared with that of the wild type strain. The fruiting bodies growth temperature of the mutant was 16~20°C in daytime and was 6~12°C at night. The highest growth temperature of fruiting bodies of the mutant was increased by 5°C than that of original strain. Through three generation investigation, we found that the mutant CGMCC1762 was stable with high temperature tolerance.

310

The aim of this work is to identify if there is sex specificity on ¹²C⁶⁺ ion-induced oxidative damage in mouse lung at different time points. Kun-Ming mice were divided into two groups, each composed of six males and six females: control group and irradiation group with a single acute dose of 4 Gy. Animals were sacrificed at 2, 4 and 12 h respectively, there lungs were removed immediately, and the oxidative stress-related biomarkers were measured by Diagnostic Reagent Kits. The results showed that the relative activities of superoxide dismutase (4 h), catalase (2 h) and Se-dependent glutathione peroxidase (12 h) have significant changes (P<0.05) between male groups and female groups, suggesting that the lungs of male mice are more sensitive to counteracting the oxidative challenge. Moreover, higher levels of malondiadehyde and lower contents of glutathione were also found in males, indicating that oxidative stress induced by ¹²C⁶⁺ ion is pronounced in the lungs of males. We thought that these sex-responded differences may be attributed to the influence of sex hormones.

329

The inverse planning for a step-and-shoot plan in intensity-modulated radiotherapy (IMRT) is usually a multiple step process. Before being converted into the MLC segments, the optimum intensity profiles of beams, which are generated by an optimization algorithm, shall be discretized into a few intensity levels. The discretization process of the optimum intensity profiles can induce deviations in the final dose distribution from the original optimum dose distribution. This paper describes a genetic algorithm for the discretization of given optimum intensity profiles. The algorithm minimizes an objective function written in terms of the intensity levels. Both the dose-based objective function, which is defined by the deviation between the dose distributions before and after the discretization, and the intensity-based objective function, which is defined by the deviation between the optimum intensity profiles and the discretization intensity profiles, have been adopted. To evaluate this algorithm, a series of simulation calculations had been carried out using the present algorithm, the even-spaced discretization and the k-means clustering algorithm respectively. By comparing the resultant discretization-induced deviations (DIDs) in intensity profiles and in dose distributions, we have found that the genetic algorithm induced less DIDs in comparison with that induced in the even-spaced discretization or the k-means clustering algorithm. Additionally, it has been found that the DIDs created in the genetic algorithm correlate with the complexity of the intensity profiles that is measured by the "fluence map complexity" .

378

PET myocardial viability imaging is the "gold standard" for the non-invasive assessment of myocardial viability. The research aims to find out the best methods of imaging interpretation in predicting the postoperative functional recovery. Twenty-one CAD patients with multi-vessel involvement were recruited. All patients underwent gated myocardial perfusion imaging(G-MPI) and FDG PET myocardial imaging within 2 weeks before coronary artery bypass grafting. The postoperative G-MPI was performed in all patients 3 months after the surgery. Out of the total 420 segments, 164 segments of ischemic myocardium were detected by preoperative G-MPI. Among them, 93 ischemic segments were identified as non-viable(difference score≥0) and the rest 71 segments were identified as viable(difference score<0). The proportion of viable segments (the ratio of viable segments versus ischemic segments) and summed difference score of metabolism to perfusion were calculated. The patients were further divided into 2 groups according to the proportion of viable myocardium: groupⅠ(the proportion≥50%, 12 cases) and groupⅡ(the proportion<50%, 9 cases) while another division was made according to SDS: group A (SDS≥0), group B (-5≤SDS<0) and group C (SDS<-5). The diagnostic accuracy of proportion of viable segments and SDS in predicting the post-revascularization improvement in the left ventricular ejection fraction by at least 5 or more ejection fraction units was 88.89% (8/9) and 55.56% (5/9) respectively. It is concluded that both approaches allow accurate evaluation of myocardial viability. Furthermore, the proportion of viable myocardium is more reliable in predicting the postoperative functional recovery.

503

In this paper, the design and analysis of a new low noise charge sensitive preamplifier for silicon strip, Si(Li), CdZnTe and CsI detectors etc. with switch control feedback resistance were described, the entire system to be built using the CMOS transistors. The circuit configuration of the CSP proposed in this paper can be adopted to develop CMOS-based Application Specific Integrated Circuit further for Front End Electronics of read-out system of nuclear physics, particle physics and astrophysics research, etc. This work is an implemented design that we succeed after a simulation to obtain a rise time less than 3ns, the output resistance less than 94Ω and the linearity almost good.

420

The performance of a compact position sensitive gamma-ray detector based on wavelength-shifting fibers coupled to YAlO₃:Ce scintillation crystal was evaluated using a Monte-Carlo simulation method. The simulation model has been setup using the GEANT4 codes. Compared with the gamma-ray detector based on the YAlO₃:Ce scintillation crystal coupled to Hamamastu R2486 position sensitive photomultiplier tube, the results indicate that the gamma-ray detector based on wavelength-shifting fibers readout has good position linearity, good spatial resolution and larger effective field of view. The image and point spread function of measured point were presented. The spatial resolution response as a function of position was obtained. The factors influencing spatial resolution and position linearity were discussed.

413

Due to its low cost, flexibility and convenience for long distance data transfer, plastic scintillation fiber (PSF) have been increasingly used in building detectors or sensors for detecting various radiations and imaging. In this work, the performance of using PSF coupled with charge-coupled devices (CCD) to build area detectors for 2D X-ray imaging is studied. We describe the experimental setup and show the obtained images from CCD. Modulation Transfer Function (MTF) of the PSF array is also presented and compared to earlier reports.

489

Based on the high energy γ-ray yield from the H-bomb D-T fusion reaction, it brings forward the idea applying the 16.76 MeV γ-ray to judge whether the H-bomb happens or not, and to deduce the explosion TNT equivalent accurately. The Monte Carlo N-Particle was applied to simulate the high energy γ-ray radiation characteristics reaching the geosynchronous orbit satellite, and the CVD diamond detector suit for the requirements was researched. A series of experiments were carried out to testify the capabilities of the diamond detector. It provides a brand-new approach to satellite-based nuclear explosion detection.

303

Thermal-hydraulic characteristic investigation on passive residual heat removal system (PRHRS) of Chinese advanced PWR was conducted to provide input data for PRHRS design and to demonstrate the feasibility of unique design features. A total of 237 sets of test data at steady state have been obtained and the main influence factors on the two-phase natural circulation flow rate and residual heat removal capability were identified. On the basis of theory analysis, a correlation of two-phase natural circulation was obtained, and relative errors of 95% test data were less than ±16%. There is a considerable effect of the system status parameters on the threshold of height between heat source and heat sink, and its correlation of two-phase natural circulation system has been obtained. The steady characteristic research shows that PRHRS has the capability of removing the core decay power through natural circulation.

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