Pub Date : 2020-06-24DOI: 10.11884/HPLPB202032.200117
Wei-Che Lai, Chen Yong, Wang Shao-Yi, Fan Quan-ping, Z. Qiangqiang, Z. Zhong, Wang Zhanshan, Cao Lei-feng
Advances in basic and applied research of conventional grating have been attracting much attention from optical engineering community. However, the higher orders diffraction contamination degrades the spectral purity obtained by conventional gratings seriously. Many designs of single-order or quasi-single-order gratings have been proposed to suppress higher-order diffraction contributions, however, their inhibitive effects on the higher order diffractions are restrained by the processing accuracy unavoidably. In this paper, we propose a grating that incorporates a quasi-periodical array of rectangular holes, and achieves larger tolerance of processing errors compared with the previously designed gratings by optimizing the probability density distribution function of the holes. This paper describes an analytical study of the diffraction property of this grating. Theoretical calculations reveal that the grating completely suppresses the 2nd, 3rd, and 4th orders diffractions, and the ratio of the 5th order diffraction efficiency to that of the 1st is as low as 0.01% even if relative errors for hole sizes exceed 20%, which greatly decreases the required processing accuracy.
{"title":"Suppression of higher diffraction orders using quasiperiodic array of rectangular holes with large size tolerance","authors":"Wei-Che Lai, Chen Yong, Wang Shao-Yi, Fan Quan-ping, Z. Qiangqiang, Z. Zhong, Wang Zhanshan, Cao Lei-feng","doi":"10.11884/HPLPB202032.200117","DOIUrl":"https://doi.org/10.11884/HPLPB202032.200117","url":null,"abstract":"Advances in basic and applied research of conventional grating have been attracting much attention from optical engineering community. However, the higher orders diffraction contamination degrades the spectral purity obtained by conventional gratings seriously. Many designs of single-order or quasi-single-order gratings have been proposed to suppress higher-order diffraction contributions, however, their inhibitive effects on the higher order diffractions are restrained by the processing accuracy unavoidably. In this paper, we propose a grating that incorporates a quasi-periodical array of rectangular holes, and achieves larger tolerance of processing errors compared with the previously designed gratings by optimizing the probability density distribution function of the holes. This paper describes an analytical study of the diffraction property of this grating. Theoretical calculations reveal that the grating completely suppresses the 2nd, 3rd, and 4th orders diffractions, and the ratio of the 5th order diffraction efficiency to that of the 1st is as low as 0.01% even if relative errors for hole sizes exceed 20%, which greatly decreases the required processing accuracy.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"072002-1-072002-6"},"PeriodicalIF":0.0,"publicationDate":"2020-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42987095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-24DOI: 10.11884/HPLPB202032.200069
Chen Xueqian, Shen Zhanpeng, Elin Zhongyang, Fan Xuanhua
The guide-slider joint of the transmission mechanism with a long stroke has a great effect on the dynamic characteristic of the structure. Aiming at the dynamic modeling on the joint part of the LM linear rolling guide in some large laser facility, the finite element (FE) model of the transmission mechanism with a long stroke is established based on the thin layer element and spring element. The modulus of the thin element and the stiffness of the spring element are identified by the model updating method and the modal experimental results. After the model update, the maximal error of the first three modal frequencies between simulation and experiment is 2.29%, and the maximal error of the point’s displacement response between simulation and experiment is 7.61% under the ambient vibration. The results of simulation and experiment are consistent, which shows that the model is effective and reasonable. The study provides a theoretical basis for the high confidence dynamic modeling on other structure with such a the joint.
{"title":"Dynamic modeling on a linear rolling guide based on thin layer element and spring element","authors":"Chen Xueqian, Shen Zhanpeng, Elin Zhongyang, Fan Xuanhua","doi":"10.11884/HPLPB202032.200069","DOIUrl":"https://doi.org/10.11884/HPLPB202032.200069","url":null,"abstract":"The guide-slider joint of the transmission mechanism with a long stroke has a great effect on the dynamic characteristic of the structure. Aiming at the dynamic modeling on the joint part of the LM linear rolling guide in some large laser facility, the finite element (FE) model of the transmission mechanism with a long stroke is established based on the thin layer element and spring element. The modulus of the thin element and the stiffness of the spring element are identified by the model updating method and the modal experimental results. After the model update, the maximal error of the first three modal frequencies between simulation and experiment is 2.29%, and the maximal error of the point’s displacement response between simulation and experiment is 7.61% under the ambient vibration. The results of simulation and experiment are consistent, which shows that the model is effective and reasonable. The study provides a theoretical basis for the high confidence dynamic modeling on other structure with such a the joint.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"072001-1-072001-6"},"PeriodicalIF":0.0,"publicationDate":"2020-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43674455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-24DOI: 10.11884/HPLPB202032.200078
Ni Xiaolong, Zhu Xufang, Yu Xin, Yao Haifeng, Chen Chunyi, Liu Zhi
To reduce the complexity and cost of partially coherent optical system, increase the convenience of partially coherent laser beam application, in this paper, we presents a method to control the coherence and divergence angle of laser beam complexly, using a liquid crystal spatial light modulator (LC-SLM). First, we introduce the basic theory and method to control the coherence and divergence angle of laser beam complexly using an LC-SLM; then, we put forward the experiment to test the coherence and divergence angle controlling accuracy. The experiment results show that, for a partially coherent laser beam with the coherence and divergence angle of 0.9 mm, 7.5 mrad and 1.5 mm, 3.8 mrad, the error of coherence is less than 5%, the root-mean-square errors of the degree of coherence are 0.027 386 and 0.031 314, and the peak-to-valley values are 0.084 658 and 0.089 103 respectively; the error of divergence angle is less than 5%, the root-mean-square errors of the divergence angle are 0.022 478 and 0.023 186, and the peak-to-valley values are 0.081 201 and 0.092 130 respectively. This method can control degree of coherence and divergence angle with high accuracy.
{"title":"Laser beam coherence and divergence angle complex controlling technique","authors":"Ni Xiaolong, Zhu Xufang, Yu Xin, Yao Haifeng, Chen Chunyi, Liu Zhi","doi":"10.11884/HPLPB202032.200078","DOIUrl":"https://doi.org/10.11884/HPLPB202032.200078","url":null,"abstract":"To reduce the complexity and cost of partially coherent optical system, increase the convenience of partially coherent laser beam application, in this paper, we presents a method to control the coherence and divergence angle of laser beam complexly, using a liquid crystal spatial light modulator (LC-SLM). First, we introduce the basic theory and method to control the coherence and divergence angle of laser beam complexly using an LC-SLM; then, we put forward the experiment to test the coherence and divergence angle controlling accuracy. The experiment results show that, for a partially coherent laser beam with the coherence and divergence angle of 0.9 mm, 7.5 mrad and 1.5 mm, 3.8 mrad, the error of coherence is less than 5%, the root-mean-square errors of the degree of coherence are 0.027 386 and 0.031 314, and the peak-to-valley values are 0.084 658 and 0.089 103 respectively; the error of divergence angle is less than 5%, the root-mean-square errors of the divergence angle are 0.022 478 and 0.023 186, and the peak-to-valley values are 0.081 201 and 0.092 130 respectively. This method can control degree of coherence and divergence angle with high accuracy.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"071008-1-071008-8"},"PeriodicalIF":0.0,"publicationDate":"2020-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44644986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-24DOI: 10.11884/HPLPB202032.200012
Jiang Xiaoguo, Yang Xinglin, Yang Guojun, Zhang Xiaoding, Li Yiding, Li Hong, Jiang Wei, W. Tao
Charge coupled device(CCD) is one kind of photoelectric solid-state imaging device with excellent performance. It has the features of large array and good image quality. Working under very complex driving timing, it usually has low frame frequency and can not meet the demand of high imaging frame rate. The method of equivalent high frame rate imaging technique is introduced based on normal CCD in this paper. Some CCDs can be drived via electrodes separately. To meet the imaging demands of high frame rate, high resolution and high quality of two frame imaging technique for pulse light images, the right kind of CCDs should be adopted. The most important is that the CCD electrodes must be controlled directly and respectively. The charge transfer period is a key point while designing CCD driving timing for separate pulse light integration, charge package transfer and readout for two pulse light images. The validation experiments for the principle of equivalent high frame rate exposure of two pulse light images has been accomplished. It is shown that two pulse light images with interval of about 2 μs can be distinguished while all CCD’s inherent excellent performance are retained. A kind of two framing camera system with simple structure can be developed based on this principle.
{"title":"Principle study on exposure technique for double pulse high speed imaging based on direct control of CCD driving electrodes","authors":"Jiang Xiaoguo, Yang Xinglin, Yang Guojun, Zhang Xiaoding, Li Yiding, Li Hong, Jiang Wei, W. Tao","doi":"10.11884/HPLPB202032.200012","DOIUrl":"https://doi.org/10.11884/HPLPB202032.200012","url":null,"abstract":"Charge coupled device(CCD) is one kind of photoelectric solid-state imaging device with excellent performance. It has the features of large array and good image quality. Working under very complex driving timing, it usually has low frame frequency and can not meet the demand of high imaging frame rate. The method of equivalent high frame rate imaging technique is introduced based on normal CCD in this paper. Some CCDs can be drived via electrodes separately. To meet the imaging demands of high frame rate, high resolution and high quality of two frame imaging technique for pulse light images, the right kind of CCDs should be adopted. The most important is that the CCD electrodes must be controlled directly and respectively. The charge transfer period is a key point while designing CCD driving timing for separate pulse light integration, charge package transfer and readout for two pulse light images. The validation experiments for the principle of equivalent high frame rate exposure of two pulse light images has been accomplished. It is shown that two pulse light images with interval of about 2 μs can be distinguished while all CCD’s inherent excellent performance are retained. A kind of two framing camera system with simple structure can be developed based on this principle.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"071001-1-071001-6"},"PeriodicalIF":0.0,"publicationDate":"2020-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43842970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.11884/HPLPB202032.190421
Zhang Guifu, Zhou Jie, Liu Youjiang
A fully-differential master-slave track-and-hold amplifier (MS-THA), with 20 GHz bandwidth is designed and fabricated using 0.13 μm SiGe BiCMOS technology. The MS-THA employs conventional switched-emitter-follower (SEF) as track-and-hold core circuit, Cherryhooper circuits as band-boosting of input buffer and output buffer. To verify the validity of the above circuits, a single-stage THA is designed together with the MS-THA. Operating with a single +3.3 V supply, 0 V input direct-voltage, 2 G/s sampling and −3 dBm input power, the MS-THA achieves a single-ended spurious free dynamic range (SFDR) of less than −23.5 dB at frequency of up to 20 GHz, and total power consumption of about 300 mW.
{"title":"一款2 G/s采样率20 GHz带宽主从式跟踪保持电路设计研究","authors":"Zhang Guifu, Zhou Jie, Liu Youjiang","doi":"10.11884/HPLPB202032.190421","DOIUrl":"https://doi.org/10.11884/HPLPB202032.190421","url":null,"abstract":"A fully-differential master-slave track-and-hold amplifier (MS-THA), with 20 GHz bandwidth is designed and fabricated using 0.13 μm SiGe BiCMOS technology. The MS-THA employs conventional switched-emitter-follower (SEF) as track-and-hold core circuit, Cherryhooper circuits as band-boosting of input buffer and output buffer. To verify the validity of the above circuits, a single-stage THA is designed together with the MS-THA. Operating with a single +3.3 V supply, 0 V input direct-voltage, 2 G/s sampling and −3 dBm input power, the MS-THA achieves a single-ended spurious free dynamic range (SFDR) of less than −23.5 dB at frequency of up to 20 GHz, and total power consumption of about 300 mW.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"063006-1-063006-8"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44975821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.11884/HPLPB202032.190352
Zhao Hai-long, Wang Gang-hua, Wang Qiang, Zhang Hengdi, Xiao Bo, Kan Mingxian, Yang Long
Magnetized Liner Inertial Fusion (MagLIF) concept has promising potentials for future energy source (Phys.Plasmas, 2014, 21:072711), it is widely applicable to large-scale pulsed power generators such as the Primary Test Stand (PTS) facility (10 MA, 100 ns). In this context, we’ve developed a zero-dimensional (0D) MagLIF simulation code basing on magneto-hydrodynamic (MHD) equations and Deuterium-Tritium (DT) fusion models. Relationships between fusion products and initial setups (magnetic field Bz0, preheat temperature T0 and so on) are explored using this code, results show optimal parameters existing under given inputs, which are very helpful for future experimental designs. Specifically, according to our simulations, critical driving current (＞21.2 MA) is essential for fuel (50∶50 DT) energy to reach breakeven, which infers that PTS facility may not be suitable for integrated MagLIF experiments. Series of calculations are performed to confirm this inference, and more practical aluminum liner experiments are proposed and designed.
{"title":"Preliminary exploration of MagLIF concept and feasibility analysis on PTS facility","authors":"Zhao Hai-long, Wang Gang-hua, Wang Qiang, Zhang Hengdi, Xiao Bo, Kan Mingxian, Yang Long","doi":"10.11884/HPLPB202032.190352","DOIUrl":"https://doi.org/10.11884/HPLPB202032.190352","url":null,"abstract":"Magnetized Liner Inertial Fusion (MagLIF) concept has promising potentials for future energy source (Phys.Plasmas, 2014, 21:072711), it is widely applicable to large-scale pulsed power generators such as the Primary Test Stand (PTS) facility (10 MA, 100 ns). In this context, we’ve developed a zero-dimensional (0D) MagLIF simulation code basing on magneto-hydrodynamic (MHD) equations and Deuterium-Tritium (DT) fusion models. Relationships between fusion products and initial setups (magnetic field Bz0, preheat temperature T0 and so on) are explored using this code, results show optimal parameters existing under given inputs, which are very helpful for future experimental designs. Specifically, according to our simulations, critical driving current (＞21.2 MA) is essential for fuel (50∶50 DT) energy to reach breakeven, which infers that PTS facility may not be suitable for integrated MagLIF experiments. Series of calculations are performed to confirm this inference, and more practical aluminum liner experiments are proposed and designed.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"062002-1-062002-10"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43302210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.11884/HPLPB202032.190464
Guo Yuewen, L. Wenyuan, Huo Yankun, Ke Changfeng, Tang Yunsheng, Duan Li, Chen Changhua
Surface roughening treatment on insulators is an important way to improve their vacuum surface flashover characteristics. However, flashover voltages of the insulators with the same roughness show big deviation because of the poor uniformity of the surface rough structure and bad repeatability of the surface roughening method. To improve the uniformity of the surface roughening and the stability of the voltage-withstanding of the vacuum insulators, sand blasting roughening treatment on the surface of the cylindrical PMMA insulators was studied. First of all, the cylindrical insulators were sprayed on the rotating platform. With the collisions of the spherical micro SiO2 particles carried by the high-speed airflow, rough structure was fabricated on the surface. After the corrosion of the HF acid, residual SiO2 particles were removed, leaving homogeneous rough structure on the surface. The changes of the surface morphology were studied by Scanning Electron Microscope and the surface roughness of the treated insulators was tested on the surface roughness meter. Surface flashover characteristics of the sand-sprayed PMMA specimens were tested on the short-pulsed high-voltage platform. The test results indicated that homogeneously rough surface was prepared by the sand blasting treatment and the surface flashover voltages of the treated insulators were improved steadily. Compared with the untreated PMMA specimens, flashover voltages of the sand blasted insulators were improved approximately 80%.
{"title":"Influence of surface sand blasting treatment on vacuum surface flashover characteristics of PMMA insulator","authors":"Guo Yuewen, L. Wenyuan, Huo Yankun, Ke Changfeng, Tang Yunsheng, Duan Li, Chen Changhua","doi":"10.11884/HPLPB202032.190464","DOIUrl":"https://doi.org/10.11884/HPLPB202032.190464","url":null,"abstract":"Surface roughening treatment on insulators is an important way to improve their vacuum surface flashover characteristics. However, flashover voltages of the insulators with the same roughness show big deviation because of the poor uniformity of the surface rough structure and bad repeatability of the surface roughening method. To improve the uniformity of the surface roughening and the stability of the voltage-withstanding of the vacuum insulators, sand blasting roughening treatment on the surface of the cylindrical PMMA insulators was studied. First of all, the cylindrical insulators were sprayed on the rotating platform. With the collisions of the spherical micro SiO2 particles carried by the high-speed airflow, rough structure was fabricated on the surface. After the corrosion of the HF acid, residual SiO2 particles were removed, leaving homogeneous rough structure on the surface. The changes of the surface morphology were studied by Scanning Electron Microscope and the surface roughness of the treated insulators was tested on the surface roughness meter. Surface flashover characteristics of the sand-sprayed PMMA specimens were tested on the short-pulsed high-voltage platform. The test results indicated that homogeneously rough surface was prepared by the sand blasting treatment and the surface flashover voltages of the treated insulators were improved steadily. Compared with the untreated PMMA specimens, flashover voltages of the sand blasted insulators were improved approximately 80%.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"065002-1-065002-6"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48704150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.11884/HPLPB202032.200145
Jinglin Huang, Minjie Zhou, Le Wei, Chen Guo, Shuang Ni, Niu Gao, L. Zeyu, Zongqin Zhao, Zhibing He, Li Bo, Song-nan Zhao, Bao-Han Zhang, Du Kai
The development of rapid detection technique with high sensitivity and high veracity for SARS-CoV-2 is of great importance for the prevention and control of epidemic. In this work, the trace spike protein (S protein) of SARS-CoV-2 in human saliva was detected by surface enhanced Raman spectroscopy (SERS) technique. Significant differences can be found between the Raman spectra of the S protein stained saliva sample and the primitive saliva sample. These results will lay the foundation for the future rapid detection of SARS-CoV-2 by SERS technique.
{"title":"Detection of spike protein of SARS-CoV-2 by surface enhanced Raman spectroscopy","authors":"Jinglin Huang, Minjie Zhou, Le Wei, Chen Guo, Shuang Ni, Niu Gao, L. Zeyu, Zongqin Zhao, Zhibing He, Li Bo, Song-nan Zhao, Bao-Han Zhang, Du Kai","doi":"10.11884/HPLPB202032.200145","DOIUrl":"https://doi.org/10.11884/HPLPB202032.200145","url":null,"abstract":"The development of rapid detection technique with high sensitivity and high veracity for SARS-CoV-2 is of great importance for the prevention and control of epidemic. In this work, the trace spike protein (S protein) of SARS-CoV-2 in human saliva was detected by surface enhanced Raman spectroscopy (SERS) technique. Significant differences can be found between the Raman spectra of the S protein stained saliva sample and the primitive saliva sample. These results will lay the foundation for the future rapid detection of SARS-CoV-2 by SERS technique.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"069001-1-069001-2"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44478960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-12DOI: 10.11884/HPLPB202032.190415
Zhang Jun-qiang, Li Lin, Li Yajuan, Jiang Tao, Xiao Chengcheng, Gu Qiang, X. Dao
The ultrafast electron diffraction (UED) facility located in Shanghai Jiao Tong University, driven by a linear electron accelerator, has a photocathode RF gun. Sometimes an RF gun arc might happen during the accelerator running, causing a cavity detuning and beam loss, then resulting in a beam energy change. It will take a long time for the beam to restore its previous energy, which will influence utilization of the facility. An energy feedback is applied to low level RF (LLRF) system after improvement of amplitude-phase loop, using a real-time feedback of the beam center position to regulate the output amplitude of LLRF, to ensure the stability of beam energy and RF gun accelerating field. A long period of stability testing indicates, that beam energy can return to its original value quickly after arc occurence, energy jitter is improved from 4.293 3×10−4 (RMS) to 2.855 7×10−4 (RMS), realizing a long term stability of beam energy.
{"title":"A beam energy feedback for ultrafast electron diffraction facility","authors":"Zhang Jun-qiang, Li Lin, Li Yajuan, Jiang Tao, Xiao Chengcheng, Gu Qiang, X. Dao","doi":"10.11884/HPLPB202032.190415","DOIUrl":"https://doi.org/10.11884/HPLPB202032.190415","url":null,"abstract":"The ultrafast electron diffraction (UED) facility located in Shanghai Jiao Tong University, driven by a linear electron accelerator, has a photocathode RF gun. Sometimes an RF gun arc might happen during the accelerator running, causing a cavity detuning and beam loss, then resulting in a beam energy change. It will take a long time for the beam to restore its previous energy, which will influence utilization of the facility. An energy feedback is applied to low level RF (LLRF) system after improvement of amplitude-phase loop, using a real-time feedback of the beam center position to regulate the output amplitude of LLRF, to ensure the stability of beam energy and RF gun accelerating field. A long period of stability testing indicates, that beam energy can return to its original value quickly after arc occurence, energy jitter is improved from 4.293 3×10−4 (RMS) to 2.855 7×10−4 (RMS), realizing a long term stability of beam energy.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"064001-1-064001-6"},"PeriodicalIF":0.0,"publicationDate":"2020-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49503747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-12DOI: 10.11884/HPLPB202032.190486
Chen Liang, Xu Jie, Liao Wenjie, Liu Hanwei, Wang Xin, Mu Baozhong
Based on the diagnostic requirements of high spatial resolution and high energy spectral resolution in the implosion compression stage of laser inertial confinement fusion (ICF), this paper proposes a large field of view and monochromatic imaging system, which combines KB microscope and diffractive crystal. Under the laboratory condition, the grid is backlight imaged by using the Fe target X-ray tube, with KB microscope and high oriented pyrolytic graphite (HOPG). The imaging results after the crystal energy selection show that the field of view of the system can reach 800 μm, and the resolution of high-resolution area imaging is 37 μm. The detecting results show that the energy resolution of the system is 28, which verifies the monochromatic performance of the system. The system takes into account large field of view, spatial resolution and energy resolution, and has an important application in the research of hot spot structure and mixing effect in the experiment of implosion compression stage.
{"title":"Experimental research of monochromatic X-ray microscopy","authors":"Chen Liang, Xu Jie, Liao Wenjie, Liu Hanwei, Wang Xin, Mu Baozhong","doi":"10.11884/HPLPB202032.190486","DOIUrl":"https://doi.org/10.11884/HPLPB202032.190486","url":null,"abstract":"Based on the diagnostic requirements of high spatial resolution and high energy spectral resolution in the implosion compression stage of laser inertial confinement fusion (ICF), this paper proposes a large field of view and monochromatic imaging system, which combines KB microscope and diffractive crystal. Under the laboratory condition, the grid is backlight imaged by using the Fe target X-ray tube, with KB microscope and high oriented pyrolytic graphite (HOPG). The imaging results after the crystal energy selection show that the field of view of the system can reach 800 μm, and the resolution of high-resolution area imaging is 37 μm. The detecting results show that the energy resolution of the system is 28, which verifies the monochromatic performance of the system. The system takes into account large field of view, spatial resolution and energy resolution, and has an important application in the research of hot spot structure and mixing effect in the experiment of implosion compression stage.","PeriodicalId":39871,"journal":{"name":"强激光与粒子束","volume":"32 1","pages":"062001-1-062001-6"},"PeriodicalIF":0.0,"publicationDate":"2020-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42051272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：