Precision measurement of neutrino oscillation parameters at INO-ICAL detector

A magnetized Iron CALorimeter (ICAL) detector at the India-based neutrino observatory (INO) is used to study neutrino oscillation sensitivity using atmospheric muon neutrino source. The ICAL detector will be able to detect muon tracks and hadron showers produced by neutrino interactions with the iron target. We have performed precision measurement analysis for the atmospheric neutrino oscillation parameters with the muon neutrino events, generated by Monte Carlo NUANCE event generator. A marginalized χ² analysis based on reconstructed neutrino energy and muon zenith angle binning scheme has been performed to determine the sensitivity for the atmospheric neutrino mixing parameters, \(\sin ^{2}\theta _{23}\) and \(| {\Delta } m^{2}_{23}|\).     

激光单脉冲时-空采样器的研究

分析了激光单脉冲时_空实时测量对时_空采样器的要求,提出了在高峰值功率密度下探测器设计的“梳导”思想,讨论了用不同长度的单模光纤束制作时_空采样器的关键技术和工艺。这种时_空采样器具有高带宽、高损伤阈值、高捕获率的优点。     

光谱位相相干电场法的参数分析及测量

从光谱位相相干电场重构法（ＳＰＩＤＥＲ）的原理出发,实现了算法、讨论时间延迟、光谱剪切量、滤波窗口宽度、色散量等几个方面的优化选取。当展宽器色散和脉冲宽度一定时,脉冲对的时间延迟存在一个最佳取值范围。相对光谱剪切量在５％～１５％间,滤波窗口宽度为／３,重构出的位相误差最小。对干涉图取平均来减小噪声的影响。用ＳＰＩＤＥＲ算法还原了脉冲的电场和位相信息,由ＳＰＩＤＥＲ测量的脉冲宽度为１７.７ fs。同时为了比较,用自相关法测量了同一脉冲,由自相关曲线可估算出脉冲宽度为１６.８ fs,与ＳＰＩＤＥＲ 的误差比为５．１％,说明了实验的有效性。     

利用激光并采用热释电探测器的实时测温系统的最优设计

基于 Kirchhoff定律 ,利用半导体激光器及钽酸锂 (L i Ta O3)热释电探测器设计了一种实用化的反射式实时测温系统。分析了该系统的测量精度、测温灵敏度及测温范围等主要技术指标与激光源的能量、仪器的工作波长、放大器带宽、光学系统的相对孔径等技术参数间的关系。给出了实际系统主要参数选择的最佳方案。     

康普顿探测器优化设计

康普顿探测器可以获得脉冲X射线照射量随时间变化的波形,探测器特性主要由收集体、介质和金属外壳的材料、尺寸决定。针对神龙一号加速器产生的X射线的能谱结构,应用蒙特卡罗模拟方法,进行探测器结构尺寸设计,获得最佳的有机玻璃介质厚度为30 mm。探测器灵敏度系数随X光能量变化的曲线表明其能量响应较差,分析与计算结果表明在收集体前加低Z金属可有效改善能量响应特性并提高灵敏度系数。计算得到用于测量神龙一号加速器的X射线照射量的康普顿探测器的灵敏度系数为6.86×1011(C/kg)-1。     

康普顿探测器优化设计

康普顿探测器可以获得脉冲X射线照射量随时间变化的波形,探测器特性主要由收集体、介质和金属外壳的材料、尺寸决定。针对神龙一号加速器产生的X射线的能谱结构,应用蒙特卡罗模拟方法,进行探测器结构尺寸设计,获得最佳的有机玻璃介质厚度为30 mm。探测器灵敏度系数随X光能量变化的曲线表明其能量响应较差,分析与计算结果表明在收集体前加低Z金属可有效改善能量响应特性并提高灵敏度系数。计算得到用于测量神龙一号加速器的X射线照射量的康普顿探测器的灵敏度系数为6.86×1011 (C/kg)-1。     

A cems study of119Sn ion-implanted into Ni

Conversion electron Mössbauer spectroscopy (CEMS) was applied to study the behaviour of¹¹⁹Sn atoms implanted into Ni at the accelerating energy of 100–400KeV and doses of 5×10¹⁵–5×10¹⁶ ions/cm² at room temperature. All CEMS spectra were measured at room temperature and successfully analyzed by two components. The energy and dose dependence of CEMS spectra were well explained by the depth distribution of¹¹⁹Sn atoms.     

The measurement of upward going muons using the MACRO detector

The upward-going muon flux (E_μ > 1 GeV) has been measured with the underground detector MACRO at LNGS. The total number of measured events is compatible at the 8% c.l. with the expected one. Moreover, the zenith angular distribution of the measured flux does not match the expectation showing a deficit in the vertical direction where the apparatus performance is best known. Assuming an oscillation hypothesis with parameters in the range recently suggested to solve the atmospheric neutrino problem, the agreement increases, but not significantly. The results of an indirect dark matter search for a signal of WIMPs from the core of the Sun and of the Earth are given. Neutrino astronomy with MACRO is giving interesting results regarding possible high energy neutrino emission from pointlike sources and coincidences of neutrino events with γ-ray bursts.     

Status ofV ub measurement with BELLE detector

Semileptonic decays ofB →X _u lv have great importance both from theoretical and experimental point of view, as they are useful for extracting the magnitude ofV _ub, one of the tiniest elements of CKM matrix. Similarly measurement ofB √ D_s×_u can be used to calculateV _ub The Belle Collaboration has measured these branching ratios and extractedV _ub for various theoretical models.     

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass M(W) using data corresponding to 2.2 fb(-1) of integrated luminosity collected in pp collisions at sqrt[s] = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470,126 W → eν candidates and 624,708 W → μν candidates yield the measurement M(W) = 80,387 ± 12(stat.) ± 15(syst.) = 80,387 ± 19 MeV/c2. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined.     

Optimization of a non-cryogenic quantum infrared detector

A study of the optimization of the detectivity of a mid-infrared double heterostructure photovoltaic detector is proposed. Simple approximate analytic expressions for the dark current are compared with full numerical calculations, and provide a physical insight into the mechanisms dominating the dark current. The analysis is performed step by step, from a simple p–n junction to the full double heterostructure. The influence of temperature, barrier band gap energy in a double heterostructure, doping density in the active region, on diffusion and generation–recombination mechanisms is analyzed. It is finally shown how the performances of a double heterostructure photovoltaic detector can be improved by controlled doping of the active region.     

热释电探测器积分响应测试系统研究

为了实现对红外探测器积分响应的自动测量,配合虚拟仪器技术搭建了一套热释电红外探测器积分响应自动测试系统。利用双绞线将测试仪器与计算机连接,以LabVIEW为开发平台编写软件测试系统,遥控测量仪器,实现计算机自动采集和处理数据实时绘制曲线,对LT-020-H型热释电红外探测器在不同调制频率下的积分响应度进行了测试并分析。在500K的黑体辐射下,探测器积分响应度达到3.5×106V/W。通过对实验结果进行分析,得到了探测器响应、黑体辐射温度以及信号调制频率之间的关系。     

Some optimum parameters of golay detector of infra-red radiation

The relation for the sensitivity of the pneumatic detector based on the analysis of the thermal, pneumatic and optical parts of the instrument is derived. From this relation the optimum diameter of the flexible mirror and the optimum gas pressure in the detector cell are calculated.List of symbols used B brightness [sb] - C thermal capacity of absorbing membrane [cal cm^–2 grad^–1] - c specific heat of gas in cell [cal g^–1 grad^–1] - D diameter of grid [cm] - d diameter of flexible mirror [cm] - E illumination [ph] - F ₂ area of light spot [cm²] - F ₃ area of flexible mirror [cm²] - f,f ₁ focal distance [cm] - f ₀ chopping frequency of infra-red radiation [sec^–1] - h depth of cell [cm] - k radiation cooling constant [cal cm^–2 sec^–1 grad^–1] - k ₀ reflectivity of flexible mirror - k ₁,k ₂,k ₃,k ₄ constants - L total length of edge of half of grid [cm] - l distance between lens and flexible mirror [cm] - M, N constants - m refractive power of flexible mirror [cm^–1] - n number of grammolecules of gas in cell - P radiative power [cal sec^–1] - p,p ₀,p pressure, atmospheric pressure, change in pressure [dyne cm^–2] - R gas constant [erg grad^–1] - r coordinate - r ₀ radius of flexible mirror [cm] - r ₁,r ₂ radii of beam of rays [cm] - t tension of flexible mirror [dyne cm^–1] - , T, T _f absolute temperature and its change [grad] - V, V volume and increase in volume [cm³] - v coordinate - v ₀ maximum height of deflection of flexible mirror [cm] - x, x distance of object and image from focal planes [cm] - , angles - specific weight of gas at pressure of 1 atm. [g cm^–3] - absorption coefficient of infra-red radiation - thermal conductivity of gas [cal cm^–1 sec^–1 grad^–1] - v number of lines of grid per 1 cm [cm^–1] - radius of light spot on grid [cm] - T time constant [sec] - ₀, ₁, ₂, ₃ light flux and its change [lm]     

热释电双波长光纤测温仪的精度分析

在介绍一种利用钽酸锂热释电探测器实现的实用化双波长光纤测温仪的基础上,着重讨论了反射辐射、探测器周围环境的热辐射、仪器工作波长的带宽,以及光路中选择性吸收气体的光谱吸收等多种因素对仪器测温精度的影响,并提出了相应的抑制措施。实验表明,采取相应的抗干扰措施后,在系统要求的测温范围400—1360℃内,其测温精度符合设计要求。     

Continuous quantum measurement with independent detector cross correlations

We investigate the advantages of using two independent, linear detectors for continuous quantum measurement. For single-shot measurement, the detection process may be quantum limited if the detectors are twins. For weak continuous measurement, cross correlations allow a violation of the Korotkov-Averin bound for the detector's signal-to-noise ratio. The joint weak measurement of noncommuting observables is also investigated, and we find the cross correlation changes sign as a function of frequency, reflecting a crossover from incoherent relaxation to coherent, out of phase oscillations. Our results are applied to a double quantum-dot charge qubit, simultaneously measured by two quantum point contacts.     

探测器点阵法测量激光光斑参数的仿真

仿真分析了用均匀分布的探测器点阵测量激光光斑方法中,探测器灵敏度的线性工作动态范围,灵敏度的一致性差异,点阵间距等参数和光斑质心位置的测量误差,光束总能量的测量误差,以及光斑的分布等。仿真结果表明,当探测器灵敏度的一致性差异小于10％,线性工作范围的动态范围大于30dB,点阵间距小于光斑直径的1/5时,光束总能量的误差小于6％,光斑质心位置的测量误差小于光斑直径的2％,拟合的光斑分布和实际光斑分布比较接近。     

探测器点阵法测量激光光斑参数的仿真

 仿真分析了用均匀分布的探测器点阵测量激光光斑方法中,探测器灵敏度的线性工作动态范围,灵敏度的一致性差异,点阵间距等参数和光斑质心位置的测量误差,光束总能量的测量误差,以及光斑的分布等。仿真结果表明,当探测器灵敏度的一致性差异小于10％,线性工作范围的动态范围大于30dB,点阵间距小于光斑直径的1/5时,光束总能量的误差小于6％,光斑质心位置的测量误差小于光斑直径的2％,拟合的光斑分布和实际光斑分布比较接近。     

The influence of some disturbing factors upon the accuracy of measurement of thermal parameters by means of a pulse method

This paper discusses the influence of the finite pulse-time effect simultaneously acting with the effect of heat source capacity, the effect of thermometer heat capacity and the effect of inertia of measuring apparatus on the accuracy of a pulse method. Further on, the relations for the maximal and effective temperature of a sample are derived. The above effects are examined separately, which allows setting some useful criterions for neglecting these effects. The results of numerical calculations are presented also graphically.     

光谱位相干涉仪参数的优化选取

模拟研究了光谱位相相干直接电场重构法的三个主要参数：时间延迟τ、频率剪切量Ω和展宽器色散φ之间的相互关系.研究结果表明：不同的待测脉冲，具有不同的最佳时间延迟τ；而τ的改变所引起的Ω的改变又限制了τ的选取范围；在此情况下只有适当调整φ才能在τ的较宽的范围内保证测量精度. 关键词： 光谱位相相干直接电场重构法 飞秒脉冲测量 光谱相干     

弱光探测器中复合抛物面聚光镜(CPC)的优化设计

基于非成像光学的原理,设计并研制了一种新的复合抛物面聚光镜(Compound parabolic concentrator,CPC)。提出基于遗传算法的聚光镜优化设计方法,将透过率作为遗传进化的目标函数,通过控制遗传算法的遗传进化方向,对CPC的结构进行优化调整。仿真实验结果表明,优化后的聚光镜入射孔径100mm,聚光比2.5:1,轴向长度84mm。当入射角为30°时,透过率达到75%以上。将此聚光镜应用于弱光探测器中,可以较好地满足器件的需要。