A 2.45 GHz electron cyclotron resonance proton ion source and a dual-lens low energy beam transport

The structure and preliminary commissioning results of a new 2.45 GHz ECR proton ion source and a dual-lens low energy beam transport (LEBT) system are presented in this paper. The main magnetic field of the ion source is provided by a set of permanent magnets with two small electro-solenoid magnets at the injection and the extraction to fine tune the magnetic field for better microwave coupling. A 50 keV pulsed proton beam extracted by a three-electrode mechanism passes through the LEBT system of length of 1183 mm. This LEBT consists of a diagnosis chamber, two Glaser lenses, two steering magnets, and a final beam defining cone. A set of inner permanent magnetic rings is embedded in each of the two Glaser lenses to produce a flatter axial-field to reduce the lens aberrations.     

Modernization of the injector for a multibeam proton accelerator

Within the program for the development of high-current charged-particle accelerators with a high acceleration rate, an injector for a 19-beam proton accelerator with a multibeam ion injection mode is described. The injector contains an ion gun with a duoplasmatron-type H₂ ion source and a multiaperture ion-optical system regulating the inclination of the ion-beam current tubes at the inputs of the corresponding channels of the accelerating structure. The cold-cathode ion source contains a system for transporting plasma from the cathode to its output aperture in magnetic fields of complex configurations, which allows stable pulsed generation of proton beams with a current amplitude of up to 3 A at an operating gas pressure in the discharge chamber of 0.2 Torr and a decrease in the flow of unionized gas emerging from the source to 2 cm³/h. It is shown that the developed ion source and the ion-optical system make it possible to increase the phase density of the beam current at the inputs of the accelerating-structure channels and to change the divergence angles.     

分孔径三视场中波红外光学系统

为了克服单一光学通道长焦距与大视场之间的矛盾,设计了一款分孔径大变倍比三视场中波红外光学系统。该光学系统采用分孔径技术,包括小视场光学通道和中视场/大视场光学通道,两个通道之间的转换通过切出切入45°放置的反射镜完成,小视场光学通道采用二次成像,仅采用6片透镜,透过率高;中视场/大视场光学通道采用三次成像;小视场光学通道与中视场/大视场光学通道共用一片反射镜和中继组,实现了共出瞳分入瞳——分孔径;小视场长焦距为1 120mm,大视场短焦距为22.58mm,变倍比达到53×;对小视场光学通道进行了三次立体折叠,对中/大视场光学通道进行了一次折叠,有效地对横向和纵向尺寸进行了控制,外形包络在270mm×217mm×258mm范围内,系统紧凑,实现了兼具长焦距和大视场的三视场中波红外光学系统。设计及实验结果表明该光学系统像质良好,满足热像仪使用要求。     

广角微型投影镜头设计

投影机更新速度快,高分辨率、轻便微小的投影机已是时代的需求。通过分析微型投影成像系统的特点,根据几何光学理论,用Zemax软件设计了一款投影显示芯片为0.61inch(1inch=2.54cm)、投射比为0.68∶1的微型投影镜头。镜头由2片非球面透镜和6片常用玻璃材料透镜组成,结构简单,系统光学总长为60mm,有效焦距为9.26mm,后工作距离大于20mm,最大口径小于23mm,全视场(FOV)为80°,相对孔径为1∶2.2。在71lp/mm特征频率处,全视场的调制传递函数均大于0.5,全视场相对畸变小于2.0%,镜头成像质量好。对微型投影系统进行容差分析,得出一套较为宽松的公差,适合生产加工。     

宽光谱长工作距弱荧光信号检测显微物镜设计

针对癌细胞突变基因诱导荧光信号弱、光谱覆盖范围宽、现有显微镜不能检测等局限,本文设计了光谱波段为450~800nm、数值孔径为0.95的荧光显微物镜。物镜采用++-结构,因宽光谱、大数值孔径像差校正难度大、透镜片数多、装调困难,前组设置成敏感组分,承载物镜装调的调校功能,承担90%以上光焦度;中间组为弱光焦度组分,用于校正大数值孔径下的二级光谱,显著降低了二级光谱校正元件的加工难度;后组为负光焦度组分,用于平像场和增大物镜的工作距离。物镜的设计参数为:总长58mm、工作距0.21mm、视场0.625mm、倍率40×、数值孔径0.95,结果表明:其像质接近衍射极限,畸变小于0.2%,满足多种癌细胞突变基因的弱信号生物监测设计要求。     

VCM磁钢自动检测系统的光学系统设计

为VCM磁钢自动检测系统设计了一套高精度的光学系统。该光学系统分为成像系统和照明系统两部分,利用远心光路方式对成像系统进行了设计。通过光学计算,给出了焦距为16mm,相对孔径为1：2．5,视场角为120°的成像系统设计参数。所试制的样机经过实验表明镜头成像清晰,性能可靠,满足测量精度要求。     

共孔径消热差红外双波段光学系统

设计了适用于制冷型320×256中波红外凝视焦平面阵列探测器和320×256长波红外凝视焦平面阵列探测器的共孔径消热差折反射式红外双波段光学系统。该系统在中波3.7~4.8μm,长波7.7~11.7μm,环境温度10~40℃下工作,其焦距为292mm,视场角为1.56°×1.875°,F/#为1.93,满足100%冷光阑效率。设计的系统共用主镜、次镜和准直镜组,利用分光镜实现中波红外、长波红外光谱分光,后接各自的校正镜组校正剩余像差。给出了设计原理、设计过程和工程设计时需考虑的一些因素,通过选择合适的光学材料、机械材料和分配光焦度,实现了两路系统在10~40℃环境温度下具有良好的成像性能。该系统成像质量良好、可加工性好、装配难度小、工程可实施性强。     

0.8×~8×新型连续变倍体视显微镜物镜的设计

介绍变倍范围0.8×～8×连续变倍体视显微镜物镜的光学变倍原理.通过计算得出前固定组、变倍组、补偿组和后固定组焦距分别为43.149mm、-26mm、-26mm和54.846mm,利用Zemax光学设计软件在数值孔径取0.15～0.2条件下各自进行优化得到初始结构参数.组合后进一步优化,数值孔径取0.1,得出最终结构参...     

The conversion of a field-emission scanning electron microscope to a high-resolution,high-performance scanning transmission electron microscope,while maintaining original functions

Recently, the reliability of field-emission electron guns has increased. In addition, the cost of computer systems for on-line processing has dropped. Hence, we should now consider the use of scanning transmission electron microscopy (STEM) for routine work, especially, in the field of biology where one may expect to utilize digital image processing techniques. An STEM has been constructed, without disturbing the original functions, by converting a commercial scanning electron microscope equipped with a fieldemission gun. The STEM is generally operated at accelerating voltage 30 kV, focal length 7.5 mm, and beam current 1?2 × 10^?10 A. Several improvements have been incorporated for removing the effects of vibration, contamination, and stray magnetic fields. Also, an adjustable detector aperture was utilized. The modified instrument was connected to an on-line digital image processing system for utilizing the information obtained from STEM images. The advantages of the modified system were studied from various viewpoints.     

Scanning magnetic microscope system utilizing a magneto-impedance sensor for a nondestructive diagnostic tool of geological samples

We have developed a scanning magneto-impedance (MI) magnetic microscope to image surface stray magnetic fields of room-temperature geological samples with submillimeter resolution. The instrument consists of a small, 30 microm diameter, 5 mm length amorphous wire-based magneto- impedance (MI) sensor without any cooling mechanisms. The spacing between the sensor head and the sample was less than 300 microm. The length of the amorphous wire and sample-to-wire distance limits the spatial resolution. We have achieved a spatial resolution of 400 microm with a magnetic resolution of 10 nT. This instrument enables us to map a two-dimensional out-of-page component of a stray magnetic field of a natural remanent magnetization over a millimeter-thick slab of a primitive ordinary chondrite meteorite, documenting dipolelike features. A comparison of element mapping images with the stray field of the meteorites reveals what individual metals carry the dipolar remanences in the meteorites. These results suggest that the scanning MI microscope offers a room-temperature operable, small, low-maintenance alternative to the scanning SQUID microscope, and can aid in the interpretation of the magnetic remanence acquisition process of a meteorite.     

小型数字投影结构光三维测量仪镜头设计

为了解决三维测量仪器的小型化问题,设计了一种数字投影结构光三维测量仪光路结构,并用Zemax软件进行了性能优化。该结构分为投影光路和照相光路,投影镜头采用反远距结构,由5片透镜组成,全视场调制传递函数大于0.35。照相镜头采用双高斯结构,由6片透镜组成,全视场调制传递函数大于0.12。两镜头口径均小于14mm,长度小于40mm,像面照度均大于90%,可以对80~120mm远的物体进行测量。投影图像像素密度为1 028×768,相机拍摄图像像素密度为1 280×960,在工作距离100mm处可以测量28mm×21mm的表面。镜头全部采用球面透镜。该结构具有测量精度高、成本低、加工容易、体积小等优点。     

A new high-aperture glycerol immersion objective lens and its application to 3D-fluorescence microscopy

High‐resolution light microscopy of glycerol‐mounted biological specimens is performed almost exclusively with oil immersion lenses. The reason is that the index of refraction of the oil and the cover slip of ~1.51 is close to that of ~1.45 of the glycerol mountant, so that refractive index mismatch‐induced spherical aberrations are tolerable to some extent. Here we report the application of novel cover glass‐corrected glycerol immersion lenses of high numerical aperture (NA) and the avoidance of these aberrations. The new lenses feature a semi‐aperture angle of 68.5°, which is slightly larger than that of the diffraction‐limited 1.4 NA oil immersion lenses. The glycerol lenses are corrected for a quartz cover glass of 220 µm thickness and for a 80% glycerol‐water immersion solution. Featuring an aberration correction collar, the lens can adapt to glycerol concentrations ranging between 72% and 88%, to slight variations of the temperature, and to the cover glass thickness. As the refractive index mismatch‐induced aberrations are particularly important to quantitative confocal fluorescence microscopy, we investigated the axial sectioning ability and the axial chromatic aberrations in such a microscope as well as the image brightness as a function of the penetration depth. Whereas there is a significant decrease in image brightness associated with oil immersion, this decrease is absent with the glycerol immersion system. In addition, we show directly the compression of the optic axis in the case of oil immersion and its absence in the glycerol system. The unique advantages of these new lenses in high‐resolution microscopy with two coherently used opposing lenses, such as 4 Pi‐microscopy, are discussed.     

Optical cell for combinatorial in situ Raman spectroscopic measurements of hydrogen storage materials at high pressures and temperatures

An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storage materials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element lenses. For combinatorial investigations, up to 19 individual powder samples can be loaded into the optical cell at one time. This cell design is also compatible with thin-film samples. To demonstrate the capabilities of the cell, in situ measurements of the Ca(BH(4))(2) and nano-LiBH(4)-LiNH(2)-MgH(2) hydrogen storage systems at elevated temperatures and pressures are reported.     

变焦系统设计的小型化

目前,随着光学设计水平的不断提高,变焦光学系统的质量可与定焦系统相媲美,正向着大倍率、大相对孔径、小型化的方向发展,变焦系统的应用也随之日益广泛。本文根据变焦系统的基本原理,利用ZEMAX软件设计了一个用于监控的变焦系统,变焦范围:200mm一600mm,变倍比:3x,镜筒长度:450mm。设计结果表明:该变焦系统较之同类设计结果,具有结构紧湊,质量轻,长度短的优点。     

磁流变液减振器中磁场强度的数学建模及有限元分析

在论述磁流变液减振器工作机理的基础上,采用一种数学建模方法建立了磁流变液减振器中磁场强度的数学模型,然后运用ANSYS编写了相应程序对该磁场强度模型进行了有限元分析,将这两种方法得到的数据进行比较分析后,最终得到了磁场强度与磁流变液减振器主要设计参数和控制参数（激励电流和线圈匝数）之间的简化数学模型,为有效的在磁流变液减振器中控制阻尼孔处磁场强度等后续工作打下基础。     

基于液体透镜的自动变焦扫描镜头的设计与验证

由于定焦镜头自身的景深问题使传统的扫码器不具备大的工作距离。为了满足工作人员在不更换扫描器的情况下既能实现近距离的信息读取又能实现十几米外的信息读取,研发了一款基于电润湿（electrowetting on dielectric,EWOD）液体透镜的自动变焦扫描镜头。通过调整液体镜片形状来实现镜头参数特别是焦距的变化,使得从近到远的所有对象都能成像在焦面上,从而达到自动变焦的效果。通过Zemax软件设计出一款成像范围为80 mm至无穷远的自动变焦扫描镜头,并完成了成像质量的验证。     

高频窄脉冲超声聚焦传感器的工艺及应用

在双金属转子复合层全自动超声特征成像检测系统中,凶柱塞孔孔径小、孔肇薄,针对此类扩散焊检测,为了提高超声成像系统的分辨率和信号的信噪比,研制了用于检测双金属转子复合层扩散焊连接质量的超声传感器.本文提出了用声程相等的理论来设计超声传感器的聚焦,利用耦合剂和工件声速的不同,把内孔铜层作为传感器的声聚焦透镜,用光学方法对传感器的聚焦声场进行了验证.制作的传感器中心频率为10 MHz,波列只有2个周期,在实际的检测中可分辨0.5 mm当量的缺陷.     

Development,production, and investigation of PMMA-based X-ray compound refractive lenses

Equipment and technology for producing X-ray refractive lenses from polymethyl methacrylate are described. Each single lens has a spherical profile with a radius of 2.38 mm. A compound lens is composed of 235 single lenses. The focal length of the compound lens for 14-keV X-ray photons is 4.8 m. The lenses developed thereby have been tested on the synchrotron radiation source of the Scientific and Engineering Complex at the Kurchatov Centre of Synchrotron Radiation and Nanotechnologies. The advantages and the drawbacks of the parabolic and spherical lenses are discussed.     

Re-evaluation of differential phase contrast (DPC) in a scanning laser microscope using a split detector as an alternative to differential interference contrast (DIC) optics

In this paper, differential phase imaging (DPC) with transmitted light is implemented by adding a suitable detection system to a standard commercially available scanning confocal microscope. DPC, a long‐established method in scanning optical microscopy, depends on detecting the intensity difference between opposite halves or quadrants of a split photodiode detector placed in an aperture plane. Here, DPC is compared with scanned differential interference contrast (DIC) using a variety of biological specimens and objective lenses of high numerical aperture. While DPC and DIC images are generally similar, DPC seems to have a greater depth of field. DPC has several advantages over DIC. These include low cost (no polarizing or strain‐free optics are required), absence of a double scanning spot, electronically variable direction of shading and the ability to image specimens in plastic dishes where birefringence prevents the use of DIC. DPC is also here found to need 20 times less laser power at the specimen than DIC.