HIRFL微束辐照装置偏转磁铁的安装准直；Alignment of Dipole Magnet in Micro-beam Line of HIRFL

微束辐照装置是将辐照样品的束斑缩小到μm量级,能够对辐照粒子进行准确定位和精确计数的实验平台,是开展辐照材料学、辐照生物学、辐照生物医学和微加工的有力工具。μm量级的束流对设备的准直安装也提出了极高的要求,对于HIRFL系统微束线上的二极磁铁,由于其所在位置的空间相当狭小,使得设计就位时磁铁的位置及角度与地面做基准时的不同,这给安装准直工作带来了挑战。通过引入变化的基准坐标值的办法,有效解决了这一难题,使全部磁铁安装误差都控制在了要求的公差范围之内。

Development of multi-channel gated integrator and PXI-DAQ system for nuclear detector arrays

A multi-channel gated integrator and PXI based data acquisition system have been developed for nuclear detector arrays with hundreds of detector units. The multi-channel gated integrator can be controlled by a programmable Cl controller. The PXI-DAQ system consists of NI PXI-1033 chassis with several PXI-DAQ cards. The system software has a user-friendly GUI which is written in C language using LabWindows/CVI under Windows XP operating system. The performance of the PXI-DAQ system is very reliable and capable of handling event rate up to 40 kHz. (C) 2010 Elsevier B.V. All rights reserved.

8×8单元CsI(Tl)探测阵列研制；Development of 88 CsI(Tl) array detector

描述了1个8×8单元CsI(Tl)探测阵列的结构和工作原理。探测阵列的每个单元是由1块前表面21 mm×21 mm、后表面23.1 mm×23.1 mm、高50 mm的CsI(Tl)棱台、1块光导和光电倍增管组成。在兰州放射性次级束流线(RIBLL)上对探测阵列进行测试,得到探测阵列对30 MeV质子的能量分辨可达2.7%,对170 MeV7Be可达1.5%,可很好地用于放射性束物理实验中带电粒子的鉴别。

64通道一维位置灵敏电流分布探测器及其数据获取系统；A 64-Channel Position Sensitive Current Distribution Detector with Data Acquisition System

针对高流强粒子束与绝缘毛细管相互作用的特点,设计制作了一套64通道一维位置灵敏电流分布探测器及其配套的数据获取系统,该探测器可分辨最小直径为1mm的束斑,通过数据获取系统可实现可视化自动数据采集。用2nA和200—2000eV电子对探测器进行了定标,并用10μA和2000eV的电子束穿越锥形毛细管后的出射电子,对探测器及数据获取系统进行测试,获得了出射粒子的位置分布谱及能量信息。

Structure evolution along the yrast-line in Pd-101

High-spin states in Pd-101 have been investigated experimentally via the Ge-76(Si-28, 3n gamma)Pd-101 reaction. The previously known bands based on the d(5/2) and h(11/2) neutron orbitals have been extended to higher-spin states, and two new structures have been observed. Spin and parity were assigned to the levels on the basis of the experimental results of the angular distribution of gamma rays deexciting the oriented states. For the ground-state band, the E-GOS (E-Gamma Over Spin) curve strongly suggests a structure transition from vibration to rotation while increasing spin.

Secondary electron time detector for mass measurements at CSRe

The Isochronous Mass Spectrometry is a high accurate mass spectrometer. A secondary electrons time detector has been developed and used for mass measurements. Secondary electrons from a thin carbon foil are accelerated by ail electric field and deflected 180 degrees by a magnetic field onto a micro-channel plate. The time detector has been tested with alpha particles and a time resolution of 197 ps (FWHM) was obtained in the laboratory. A mass resolution around 8 x 10(-6) For Delta m/m was achieved by using this time detector in a pilot mass measurement experiment.

Investigation of add-back effects in a segmented Clover detector

The resolution and the summing characteristics of an EXOGAM segmented Clover germanium detector has been studied for use it in gamma spectroscopic experiments. The measurements have been performed with standard radioactive sources of Eu-152, Ba-133 and beta-delayed gamma-rays from Ir-176 decay. The data analytic results, realized by software, are presented in this paper.

Investigation of the energy resolution with a RETGEM detector

A novel Micro-pattern gaseous detector (MPGD), thick GEM with electrodes made of a resistive material (RETGEM) is presented. In this paper we mainly investigate the energy resolution of a RETGEM in Ar+CO2 with different gas mixtures. The results indicate that an energy resolution 30% in single and double mode can be obtained. The existence of an optimum energy resolution is discussed.

An etched porous interface for on-line capillary electrophoresis-based two-dimensional separation system

The construction and evaluation of an on-column etched fused-silica porous junction for on-line coupling of capillary isoelectric focusing (CIEF) with capillary zone electrophoresis (CZE) are described. Where two separation columns were integrated on a single piece of fused-silica capillary through the etched similar to4 to 5-mm length porous junction along the capillary. The junction is easily prepared by etching a short section of the capillary wall with HF after removing the polyimide coating. The etched section becomes a porous glass membrane that allows only small ions related to the background electrolyte to pass through when high voltage is applied across the separation capillary. The primary advantages of this novel porous junction interface over previous designs (in which the interface is usually formed by fracturing the capillary followed by connecting the two capillaries with a section of microdialysis hollow fiber membrane) are no dead volume, simplicity, and ruggedness, which is particularly well suited for an on-line coupling capillary electrophoresis-based multiple dimensional separation system. The performance of the 2D CIEF-CZE system constructed by such an etched porous junction was evaluated by the analyses of protein mixtures.

On-line concentration of neutral and charged species in capillary electrochromatography with a methacrylate-based monolithic stationary phase

A method involving self-concentration, on-column enrichment and field-amplified sample stacking for on-line concentration in capillary electrochromatography with a polymer monolithic column is presented. Since monolithic columns eliminate the frit fabrication and the problems associated with frits, the experimental conditions could be more flexibly adjusted to obtain higher concentration factor in comparison with conventional particulate packed columns. With self-concentration effect, the detection sensitivity of benzene and hexylbenzene is improved by a factor of 4 and 8, respectively. With on-column enrichment and ultralong injection, improvement as high as 22 000 times in detection sensitivity of benzoin is achieved. Furthermore, a combination of the three above-mentioned methods yields up to a 24000-fold improvement in detection sensitivity for caffeine, a charged compound. Parameters affecting the efficiency of on-line concentration are investigated systematically. In addition, equations describing on-line concentration process are deduced.

On-line introduction of high-pressure gas-liquid sample for capillary gas chromatographic analysis

An on-line sample introduction technique in capillary gas chromatograph (CGC) for the analysis of high-pressure gas-liquid mixtures has been designed and evaluated. A sample loop of 0.05 muL and a washing solvent loop of 0.5 muL are mounted on a 10-port switching valve, which serves as the injection valve. A capillary resistor was connected to the vent of sample loop in order to maintain the pressure of the sample. Both the sample and the washing solvent are transferred into the split-injection port through a narrow bore fused silica capillary inserted into the injection liner through a septum. The volume of the liner is used both as the pressure-release damper and evaporation chamber of the sample. On-line analysis of both reactants and resultants in ethylene olimer reaction mixture at 5 MPa was carried out, which demonstrated the applicability of the technique. (C) 2004 Elsevier B.V. All rights reserved.