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Angular Momentum Conserved Coherent State for an Electron in a Uniform Magnetic Field
FAN Hong-yi, ZOU Hui, FAN Yue,
Chin. Phys. Lett. 1999, 16 (10):
706-708
.
For an electron in the uniform magnetic field, we construct the angular momentum conserved coherent state || r2, l 〉, based on which we establish a new complete and orthonormal << l, r | representation, where l represents the angular momentum and r the electron's orbit radius. Squeezing of the state | l , r >> is examined.
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Octupole Deformation and Signature Inversion in 145Ba
ZHU Sheng-jiang, M. Sakhaee, J. H. Hamilton, A. V. Ramayya, GAN Cui-yun, ZHU Ling-yan, YANG Li-ming, LONG Gui-lu, PAN San-li, B. R. S. Babu, J. K. Hwang, W. C. Ma, J. Komicki, X. Q. Zhang, E. F. Jones, J .D. Cole, R. Aryaeinejad, M.W. Drigert, J. O. Rasmussen M. A. Stoyer, S. Y.Chu, K. E. Gregorich, M.F.Mohar, S. G. Prussin, I. Y. Lee, Yu. Ts. Oganessian, G. M. Ter-Akopian, A. V. Daniel
Chin. Phys. Lett. 1999, 16 (10):
715-717
.
High spin states in Neutron-rich odd-N 145Ba nucleus have been investigated from study of prompt γ -rays in spontaneous fission of 252Cf. The alternating party bands are identified indicating octupole deformation with simplex quantum number s = - i. The groud state band shows signature splitting and inversion at low spin. These collective band structures exhibit the competition and co-existence between symmetric and asymmetric shapes.
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Investigation of Effective Nonlinear Coefficient of Nd3+-Doped GdCOB and YCOB
LÜ, Jun-hua, LI Guang-ming, ZHANG Shu-jun, CHEN Huan-chu, GONG Bo, WANG Ji-yang, LIU Yao-gang, JIANG Min-hua, SHAO Zong-shu
Chin. Phys. Lett. 1999, 16 (10):
726-727
.
Second harmonic generation conversion efficiencies of Nd:YCOB and Nd:GdCOB were measured, the effective nonlinear coefficient (deff) for both crystals at different phase-matching angles were estimated by comparison with a KTP crystal. The self-frequency doubling laser performance of these crystals were theoretically calculated by using these deff values and slope efficiency of the fundamental wave and lasing threshold. The results coincide very well.
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Femtosecond Time-Resolved Exciton Recombination Dynamics in ZnO Microcrystallite Thin Films at Room Temperature
ZHANG Wei-li, CHAI Lu, XING Qi-rong, WANG Qing-yue, K. S . Wong, Ping Yu, H. Wang, Z. K. Tang, G. K. L, Wong
Chin. Phys. Lett. 1999, 16 (10):
728-730
.
We report the femtosecond time-resolved studies of room temperature exciton recombination and ultrafast stimulated emission dynamics in ZnO microcrystallite thin films. A free exciton photoluminescence lifetime of few tens of picoseconds and a decay time of a few picoseconds for the stimulated emission were observed. The relatively slow rise time (3ps) for the P band as the result of exciton-exciton scattering compared with the 0.8 ps rise time for the N band attributed to electron-hole plasma recombination clearly distinguished the two stimulated emission processes.
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Planar Optical Waveguides in KNbO3 Formed by MeV B and He Ion Implantation
LI Yan, XIA Zong-huang, SHEN Ding-yu, WANG Xue-mei, ZHAO Qiang, MA Xiao-yan, SHEN De-zhong, WANG Kui-ru
Chin. Phys. Lett. 1999, 16 (10):
731-733
.
Planar optical waveguides in single crystals of KNbO3 were fabricated by MeV B and He ion implantation. The depth profiles of radiation damage in these waveguides were compared and analyzed by high resolution transmission electron microscope. Non leaky waveguiding modes (TE0 and TM0), which are due to implantation induced increase of nb and nc, were observed in 6.0 MeV B ion implantated waveguides with a dose of 1 x 1015cm-2.
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Loss of Light Yield of Doped Lead Tungstate Crystals After Irradiation
HE Jing-tang, LÜ, Yu-sheng, CHEN Duan-bao, LI Zu-hao, BIAN Jian-guo, ZHU Guo-yi, TANG Xiao-wei, CHEN Gang, ZHENG Lian-rong, CHEN Xiao-hong, REN Shao-xia
Chin. Phys. Lett. 1999, 16 (10):
745-746
.
Loss of light yield of doped lead tungstate crystals after irradiation with a low dose rate has been observed. The La, Pr, and Y doping may improve radiation hardness, whereas Bi or Mo doping is harmful.
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Influence of Sb on the Scintillation Properties of Lead Tungstate Crystal
LIU Xian-cai, HU Guan-qin, FENG Xi-qi, LI Pei-jun, ZHANG Ming-rong, XU Li, YIN Zhi-wen
Chin. Phys. Lett. 1999, 16 (10):
761-763
.
Sb-doped lead tungstate (PWO) crystals were grown and investigated. The measurements of Sb content in crystals indicated that the segregation coefficient of Sb in PWO is about 0.63. Even with a little Sb3+ introduced into PWO crystal, the transmission, especially the light yield was enhanced significantly. Furthermore, after the Sb-doped PWO crystals were annealed, not only the fast component still remained a high percentage but also the radiation hardness was improved evidently. The main reason may be that Sb-doping can compensate the composition deficiency and then reduce the density of hole centers such as Pb3+and O-.
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In Situ Rutherford Backscattering Spectrometry Analysis of Films by Combination with Sputter Etching
JIANG Lei, LIU Bo, ZHOU Zhu-ying, HE Mian-hong, ZHAO Guo-qing, ZONG Xiang-fu
Chin. Phys. Lett. 1999, 16 (10):
770-772
.
We have set up an experimental system consisting of an ion gun and a Rutherford backscattering spectrometry(RBS) analysis chamber. Using this system, in situ 2MeV 4He+ RBS analysis of films is carried out by combination with sputter etching of low energy Ar+ ions. As an example of the sputtering/RBS method, the analysis of three samples, i.e., Si/(GexSi1-x/Si)/Si(100), WSix/SiO2/Si and CoSix/Si, is presented in this paper. After an appropriate fraction of the thick layer is removed by sputtering, the back edge of the Ge peak is separated from Si RBS spectrum on the interface and the O peak of the buried SiO2 layer can be identified. The change of the doped Ti and W concentrations related to Co on the top surface is observed. The advantages of this analytical method and its possible applications in film are discussed.
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Field Emission from Acid Treated Diamond Films
YUAN Guang, JI Hong, HAN Li, WANG Xiu-feng, GU Chang-zhi, ZHANG Bao-lin, JIANG Hong, WANG Yong-zhen, ZHAO Hai-feng, TIAN Yuan, JIN Chang-chun, JIN Yi-xin
Chin. Phys. Lett. 1999, 16 (10):
773-774
.
A stable electron emission was obtained at as low as about 2.5V/μm from acid treated diamond films. The emission data were fitted with Folwer-Nordheim theory. It is found that the non-electrons are emitted from some protrusions on surface of diamond films, and that after acid treatment, the effective work function is lowered, and the emission area is increased to two folds of those of as-grown films. These results were discussed.
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28 articles
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