Northwest Institution of Nuclear Technology

Fengcheng, China

Northwest Institution of Nuclear Technology

Fengcheng, China
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Shen Y.,CAS Xi'an Institute of Optics and Precision Mechanic | Wang Y.,CAS Xi'an Institute of Optics and Precision Mechanic | Luan K.,Northwest Institution of Nuclear Technology | Chen H.,State Key Laboratory of Laser Interaction with Matter | And 2 more authors.
IEEE Photonics Journal | Year: 2017

We report on an efficient wavelength-tunable gain-switched and gain-switched mode-locked Er3+-doped double-clad fiber laser with a linear cavity. Stable gain-switching and gain-switched mode-locking were achieved with slope efficiencies of 28.6% and 34.5% with respect to launched pump power, respectively. The gain-switched laser pulses were generated with a maximum average output power of around 110 mW, pulse width of 661.2 ns and calculated peak power of ~16.5 W at a repetition rate of 10 kHz. At the same repetition, the gain-switched mode-locked laser pulses were generated with a maximum average output power of around 514 mW, sub-pulse repetition rate of ~30.7 MHz, peak power of higher than 154 W at a repetition rate of 10 kHz when the wavelength was tuned to 2.78 μm. This is, to the best of our knowledge, the first demonstration of a gain-switched self-started mode-locked fiber laser near 3 μm. OAPA


Li P.,Xi'an Jiaotong University | Liu M.-H.,CAS Xinjiang Technical Institute of Physics and Chemistry | He C.-H.,Xi'an Jiaotong University | Guo H.-X.,Northwest Institution of Nuclear Technology | And 2 more authors.
Chinese Physics B | Year: 2017

Different SiGe processes and device designs are the critical influences of ionizing radiation damage. Based on the different ionizing radiation damage in SiGe HBTs fabricated by Huajie and an IBM SiGe process, quantitatively numerical simulation of ionizing radiation damage was carried out to explicate the distribution of radiation-induced charges buildup in KT9041 and IBM SiGe HBTs. The sensitive areas of the EB-spacer and isolation oxide of KT9041 are much larger than those of the IBM SiGe HBT, and the distribution of charge buildup in KT9041 is several orders of magnitude greater than that of the IBM SiGe HBT. The result suggests that the simulations are consistent with the experiment, and indicates that the geometry of the EB-spacer, the area of the Si/SiO2 interface and the isolation structure could be contributing to the different ionizing radiation damage. © 2017 Chinese Physical Society and IOP Publishing Ltd.


Zhang H.,Northwest Institution of Nuclear Technology | Jin P.,Northwest Institution of Nuclear Technology | Liu W.,Northwest Institution of Nuclear Technology | Liu W.,Xi'an Jiaotong University | And 2 more authors.
Acta Seismologica Sinica | Year: 2013

Calculating accurate regional phase travel-times through regional 3D velocity models constructed is one of the important means to improve regional seismic event location accuracy. Using local 1D model, ground truth (GT) events and geological data, construction of 3D velocity model is carried out as follows: First, we construct an initial 3D velocity structure through Kriging method using some local 1D velocity models; then, modify it repeatedly by GT event travel-times and geological data until the minimum travel-time bias is reached; and finally, the modified 3D velocity model is obtained. Location testing is performed with different velocity models. It shows that the modified 3D velocity model can improve regional event location accuracy, and the bias of epicenters is decreased by about 20% statistically.


Li P.,CAS Xinjiang Technical Institute of Physics and Chemistry | Li P.,University of Chinese Academy of Sciences | Guo H.-X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Guo H.-X.,University of Chinese Academy of Sciences | And 6 more authors.
Chinese Physics Letters | Year: 2015

We present a study on the single event transient (SET) induced by a pulsed laser in different silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) with the structure of local oxidation of silicon (LOCOS) and deep trench isolation (DTI). The experimental results are discussed in detail and it is demonstrated that a SiGe HBT with the structure of LOCOS is more sensitive than the DTI SiGe HBT in the SET. Because of the limitation of the DTI structure, the charge collection of diffusion in the DTI SiGe HBT is less than that of the LOCOS SiGe HBT. The SET sensitive area of the LOCOS SiGe HBT is located in the collector-substrate (C/S) junction, while the sensitive area of the DTI SiGe HBT is located near to the collector electrodes. ©2015 Chinese Physical Society and IOP Publishing Ltd.


Zhang J.-X.,Xi'an Jiaotong University | He C.-H.,Xi'an Jiaotong University | Guo H.-X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Guo H.-X.,Northwest Institution of Nuclear Technology | And 4 more authors.
Microelectronics Reliability | Year: 2015

Abstract A 3-D simulation of single event effects (SEEs) for domestic Silicon-Germanium heterojunction bipolar transistor (SiGe HBT) in extreme environment is performed with TCAD simulation tools. The influences of environment temperature and linear energy transfer (LET) on SEE are investigated. The combined effects of temperature and LET are also discussed. The results show some interesting phenomena by analyzing collected charges and transient current. The collected charges increase as temperature rises, but the current peaks decline with temperature increasing at base, collector and substrate. However, the peak of emitter transient current rises up and then declines. As LET rises, the collected charges go up linearly, and the transient current peaks also increase but their growth trends are slow. Mobility, carrier ionization and recombination of various regions at different conditions are the main causes of these differences. Current transient is very severe at low temperature. But charge collection is sensitive to high temperature and high LET. Transient pulse caused by diffusion mechanism may have a serious effect on SEEs. © 2015 Elsevier Ltd.


Li P.,CAS Xinjiang Technical Institute of Physics and Chemistry | Li P.,University of Chinese Academy of Sciences | Guo H.-X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Guo H.-X.,University of Chinese Academy of Sciences | And 10 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2015

With the rapid development of satellite, manned space flight and deep space exploration technology, semiconductor devices are used in extreme environments, especially in radiation and low temperature environment. SiGe HBT is a potential candidate for space applications because of its inherent robustness to total ionizing dose (TID) radiation. However, due primarily to charge collection through the collector-substrate (CS) junction and the relatively low substrate doping, SiGe HBTs are vulnerable to single event effects (SEEs) because of new features of process and structure. Thus, the SEE becomes a key factor in restricting space applications of SiGe HBTs. This paper presents an SEE hardening approach that uses a dummy collector to reduce charge collection in the SiGe HBT. The dummy collector is obtained by using the silicon space between adjacent HBTs. It is obtained without any process modification or area penalty. At first, we build simulation models for both normal and hardened SiGe HBTs, and then carry out SEE simulations respectively. The charge collection mechanism is obtained by analyzing the transient current and charge collection changes at different ion incident positions. Unlike the normal HBT, we can see that charge is continuously collected by the dummy CS junction. This causes more charges diffuse outward and the charges available for collector terminal to be reduced. For all ion incident positions, in the case of hardening, the drift components of charge collection are approximately the same, while the diffusion charge collection components are nearly completely compressed. During SEE, the CS junction either directly collects the deposited charges through drift within the potential funnel or indirectly collects charges after they have arrived at the junction after diffusion. The diffusion length of the carriers is on the order of tens of microns or more. Hence a dummy CS junction should be able to reduce the quantity of diffusive charges collected by the HBT collector. The actual charges collected by the collector are effectively reduced. The emitter and base charge collection also decrease by the dummy collector to different extents. Dummy-collector effectively mitigates the SEE of SiGe HBT. The SEE sensitive area of SiGe HBT is also effectively reduced by half. This work is carried out for the SiGe HBT circuit level radiation hardening design of single event effects ©, 2015, Chinese Physical Society. All right reserved.


Pan L.,Xi'an Jiaotong University | Pan L.,Northwest Institution of Nuclear Technology | Wang H.-R.,Xi'an Jiaotong University | Yao E.-R.,Xi'an Jiaotong University | Wang X.-B.,Xi'an Jiaotong University
Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics | Year: 2015

Since the high-speed objects will suffer the strong impact which could lead to the structural damage on the objects during the whole process of water-entry, the cushion mechanism has been the key issue of the water-entry process. According to the bubble dynamics and fluid mechanics, this paper proposed a method to reduce the water-entry impact by giving the cylinder an air nozzle, in order to study the law of its influence on the water-entry impact. The mathematical model of the head-jetting at cylinder was set up and the mechanism of reduce the water-entry impact was suggested. The impact pressure of the head-jetting at cylinder and the direct-entry at cylinder is compared and verified by using numerical simulation method. © 2015, Science Press. All right reserved.


Zhang J.-X.,Xi'an Jiaotong University | He C.-H.,Xi'an Jiaotong University | Guo H.-X.,CAS Xinjiang Technical Institute of Physics and Chemistry | Guo H.-X.,Northwest Institution of Nuclear Technology | And 4 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2014

In this paper we establish a three-dimensional (3D) numerical simulation model of domestic SiGe heterojunction bipolar transistor (SiGe HBT) by using technology computer aided design tools, to study the bias effect on single event effect (SEE) of SiGe HBT. The response relationship between SEE and the bias of SiGe HBT is identified based on the analyses of transient current peak and charge collection of each terminal. The results show that the worst biases for SEE are different for different terminals. Even for the same terminal, the worst biases for charge collection and transient current peak are different. This phenomenon is caused mainly by the influence of applied electric field and the change of carrier transport mode. ©, 2014, Chinese Physical Society.


Lu Y.,Northwest Institution of Nuclear Technology | Song Z.-H.,Northwest Institution of Nuclear Technology | Li G.,Northwest Institution of Nuclear Technology | Tan X.-J.,Northwest Institution of Nuclear Technology | And 2 more authors.
Chinese Physics C | Year: 2015

The resistance to neutron irradiation of LaBr3 scintillator was studied in this work. The change of background counting rate, light output and energy resolution of the LaBr3 scintillator were analyzed to determine whether the scintillator was damaged under different neutron flux rates induced by 241Am-Be, D-T neutron generator, and reactor neutron source. The results show that the neutron radiation damage in LaBr3 scintillator is mainly affected by neutron flux rate. Under low flux rate, the properties of the scintillator were hardly changing, while under high flux rate, there is obvious deterioration in the background spectra and in the energy resolution because of the neutron activation. After a period, the neutron radiation damage will spontaneously recover. © 2015 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.


Yang J.,Northwest Institution of Nuclear Technology | Sun B.,Northwest Institution of Nuclear Technology | Zhu Z.,Northwest Institution of Nuclear Technology | Shi Y.,Northwest Institution of Nuclear Technology
Proceedings - 7th Asia-Pacific Conference on Environmental Electromagnetics, CEEM 2015 | Year: 2015

The polarization and incident angle of the incident plane wave influence the electromagnetic shielding effectiveness (EMSE). By calculating the attenuated field of an infinite metal plate immediately from Maxwell's Equations or using the model of transmission line, EMSE versus the incident angle for different polarizations can be plotted. EMSE increases as the incident angle getting larger for perpendicular polarized incident wave and it decreases with the incident angle for parallel polarized incident wave. For frequently used shielding materials, the deviation between normal incidence and different polarized incident wave is approximately a constant for a given incident angle in the range of a widen frequency spectrum (1 Hz∼1 GHz). © 2015 IEEE.

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