Pub Date : 2023-11-01DOI: 10.1088/1748-0221/18/11/c11007
K. Yamasaki, K. Okuda, J. Kono, A. Saito, D. Mori, R. Suzuki, Y. Kambara, R. Hamada, S. Namba, K. Tomita, Y. Pan, N. Tamura, C. Suzuki, H. Okuno
Abstract We have developed a Thomson scattering measurement system for the cascade arc discharge device designed for the plasma window (PW) application study. The PW is one of the plasma application techniques that sustain the steep pressure gradient between high pressure (10–100 kPa) and a vacuum environment due to the thermal energy of the plasma. Since the plasma thermal energy is the essential parameter for the pressure separation capability of PW, we installed the Thomson scattering measurement system to observe the electron density and temperature within the anode and cathode of the PW for the detailed analysis of the pressure separation capability. The frequency-doubled Nd:YAG laser (532 nm, 200 mJ, 8 ns) was employed for the probe laser. The scattered light was fed to the triple grating spectrometer. The notch filter between the first and second grating eliminated the stray light, realizing a sufficiently high signal-to-noise ratio. The Thomson scattering measurement system successfully obtained the electron density and temperature of the cascade arc plasma at 20 mm downstream from the tip of the cathode. The installed system successfully obtained the Thomson scattering spectrum and showed that the electron density increased from 2 × 10 19 m -3 to 7 × 10 19 m -3 with the discharge power, while the electron temperature was almost constant at about 2 eV. The obtained data successfully contributed to the study of the pressure separation capability of the PW.
摘要针对等离子体窗(PW)的应用研究，开发了一套用于串级电弧放电装置的汤姆逊散射测量系统。PW是一种等离子体应用技术，由于等离子体的热能，它可以在高压(10-100千帕)和真空环境之间维持陡峭的压力梯度。由于等离子体热能是PW压分离能力的重要参数，我们安装了汤姆逊散射测量系统，观察PW阳极和阴极内部的电子密度和温度，详细分析PW的压分离能力。探测激光采用倍频Nd:YAG激光器(532 nm, 200 mJ, 8 ns)。散射光被送入三光栅光谱仪。第一和第二光栅之间的陷波滤波器消除了杂散光，实现了足够高的信噪比。汤姆逊散射测量系统成功地获得了距阴极尖端下游20 mm处串级电弧等离子体的电子密度和温度。实验结果表明，随着放电功率的增加，电子密度从2 × 10 19 m -3增加到7 × 10 19 m -3，而电子温度基本保持在2 eV左右。获得的数据成功地为PW的压力分离能力的研究做出了贡献。
{"title":"Development of the Thomson scattering measurement system for cascade arc device with indirectly heated hollow cathode","authors":"K. Yamasaki, K. Okuda, J. Kono, A. Saito, D. Mori, R. Suzuki, Y. Kambara, R. Hamada, S. Namba, K. Tomita, Y. Pan, N. Tamura, C. Suzuki, H. Okuno","doi":"10.1088/1748-0221/18/11/c11007","DOIUrl":"https://doi.org/10.1088/1748-0221/18/11/c11007","url":null,"abstract":"Abstract We have developed a Thomson scattering measurement system for the cascade arc discharge device designed for the plasma window (PW) application study. The PW is one of the plasma application techniques that sustain the steep pressure gradient between high pressure (10–100 kPa) and a vacuum environment due to the thermal energy of the plasma. Since the plasma thermal energy is the essential parameter for the pressure separation capability of PW, we installed the Thomson scattering measurement system to observe the electron density and temperature within the anode and cathode of the PW for the detailed analysis of the pressure separation capability. The frequency-doubled Nd:YAG laser (532 nm, 200 mJ, 8 ns) was employed for the probe laser. The scattered light was fed to the triple grating spectrometer. The notch filter between the first and second grating eliminated the stray light, realizing a sufficiently high signal-to-noise ratio. The Thomson scattering measurement system successfully obtained the electron density and temperature of the cascade arc plasma at 20 mm downstream from the tip of the cathode. The installed system successfully obtained the Thomson scattering spectrum and showed that the electron density increased from 2 × 10 19 m -3 to 7 × 10 19 m -3 with the discharge power, while the electron temperature was almost constant at about 2 eV. The obtained data successfully contributed to the study of the pressure separation capability of the PW.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135566155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1748-0221/18/11/p11001
Yubo Ma, Jie Wu, Xiaochang Jiang, Boyi Xu, Shengyu Qi
Abstract Digital bandwidth interleaving (DBI) is a technique that can simultaneously increase system sampling rate and bandwidth. While DBI can reduce the impact of clock jitter on the dynamic performance of the system compared to time-interleaved sampling systems, achieving dynamic performance comparable to time-interleaved analog-to-digital converters (TIADC) remains challenging due to phase misalignment in crossover bands caused by analog filters and nonlinearity in analog mixers. To address these issues, this paper proposes a method to calibrate DBI sampling systems using PRBS signals. This method involves injecting pseudo-random binary sequence (PRBS) signal into the system input as a background signal and calculating the correlation between the output sampling sequence and the PRBS sequence to obtain the response of each sampling channel. Compared with traditional single tone signal or pulse signal, this method offers a more efficient background calibration method. To verify the effectiveness of this method, this paper designed a hybrid parallel sampling system combining DBI and TIADC with a 20 GSPS sampling rate and 8 GHz bandwidth to evaluate the effectiveness of the calibration method. In the performance test of the sampling system before and after calibration, this calibration method improved the system's Signal-to-Noise and Distortion Ratio (SINAD) by up to 13 dB, Spurious Free Dynamic Range (SFDR) by up to 27 dB, and phase response flatness better than 0.3 radians.
{"title":"An efficient calibration method for digital bandwidth interleaving sampling system","authors":"Yubo Ma, Jie Wu, Xiaochang Jiang, Boyi Xu, Shengyu Qi","doi":"10.1088/1748-0221/18/11/p11001","DOIUrl":"https://doi.org/10.1088/1748-0221/18/11/p11001","url":null,"abstract":"Abstract Digital bandwidth interleaving (DBI) is a technique that can simultaneously increase system sampling rate and bandwidth. While DBI can reduce the impact of clock jitter on the dynamic performance of the system compared to time-interleaved sampling systems, achieving dynamic performance comparable to time-interleaved analog-to-digital converters (TIADC) remains challenging due to phase misalignment in crossover bands caused by analog filters and nonlinearity in analog mixers. To address these issues, this paper proposes a method to calibrate DBI sampling systems using PRBS signals. This method involves injecting pseudo-random binary sequence (PRBS) signal into the system input as a background signal and calculating the correlation between the output sampling sequence and the PRBS sequence to obtain the response of each sampling channel. Compared with traditional single tone signal or pulse signal, this method offers a more efficient background calibration method. To verify the effectiveness of this method, this paper designed a hybrid parallel sampling system combining DBI and TIADC with a 20 GSPS sampling rate and 8 GHz bandwidth to evaluate the effectiveness of the calibration method. In the performance test of the sampling system before and after calibration, this calibration method improved the system's Signal-to-Noise and Distortion Ratio (SINAD) by up to 13 dB, Spurious Free Dynamic Range (SFDR) by up to 27 dB, and phase response flatness better than 0.3 radians.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"35 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1748-0221/18/11/p11004
Brian J. Vaughn
Abstract It is typical in the accelerator field to model machine components, especially RF cavities, as parallel RLC resonators. To properly model wake-fields, knowledge of the time-domain voltage resulting from beam excitation is often necessary. While analytical and quasi-analytical expressions are available to accomplish this for common bunch distributions such as the Gaussian, analogous results for less standard distributions can be difficult or computationally-taxing to obtain using direct methods, which opens the door for the development of a more generalized technique. In this paper, a formulation is created that allows for the simple computation of the time-domain voltage waveform of an RLC resonator. The formulation uses the Cauchy Residue Theorem to extract the convolution result from the Fourier Domain, and if current distribution Fourier Transform has no poles, knowledge of its value is only required at one specific evaluation point. This greatly simplifies the computation of the time domain voltage for a large amount of bunch distributions both common and uncommon. Accuracy considerations for this technique and the approximation of accelerator components as RLC resonators are also discussed, resulting the development of a figure of merit for quantifying the robustness of this type of approximation.
{"title":"A simple, flexible technique for RF cavity wake-field calculations","authors":"Brian J. Vaughn","doi":"10.1088/1748-0221/18/11/p11004","DOIUrl":"https://doi.org/10.1088/1748-0221/18/11/p11004","url":null,"abstract":"Abstract It is typical in the accelerator field to model machine components, especially RF cavities, as parallel RLC resonators. To properly model wake-fields, knowledge of the time-domain voltage resulting from beam excitation is often necessary. While analytical and quasi-analytical expressions are available to accomplish this for common bunch distributions such as the Gaussian, analogous results for less standard distributions can be difficult or computationally-taxing to obtain using direct methods, which opens the door for the development of a more generalized technique. In this paper, a formulation is created that allows for the simple computation of the time-domain voltage waveform of an RLC resonator. The formulation uses the Cauchy Residue Theorem to extract the convolution result from the Fourier Domain, and if current distribution Fourier Transform has no poles, knowledge of its value is only required at one specific evaluation point. This greatly simplifies the computation of the time domain voltage for a large amount of bunch distributions both common and uncommon. Accuracy considerations for this technique and the approximation of accelerator components as RLC resonators are also discussed, resulting the development of a figure of merit for quantifying the robustness of this type of approximation.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"34 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135514609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1748-0221/18/11/t11001
L. Mendoza, C. Avila, R. Rodríguez, L. Loaiza, G. Roque
Abstract We present the results of a GAMOS/GEANT4 computer simulation of a standard X-ray mammography system, which consists of a Tungsten 28 kVp polychromatic X-ray source with a 50 μm Rh filter, a mammography phantom with Al 2 O 3 spherical specks of different diameters, and a generic pixel detector (55 μm × 55 μm pixel size) with different types of semiconductor sensors. The number of photons simulated is calibrated to produce similar entrance surface dose (ESD) as the one used by a standard clinical mammography screening. Estimates of Contrast to Noise Ratio (CNR) as a function of ESD, sensor thickness and microcalcification diameter are presented for four different sensor materials: Silicon (Si), Cadmium Telluride (CdTe), Gallium Arsenide (GaAs) and Perovskite (MAPbI3). For the X-ray energy spectrum and pixel size considered, and an ESD dose of 4 mGy, our study shows that, with the exception of Si, these sensors, as thin as 200 μm, are able to resolve (with at least 3 standard deviations above background) Al 2 O 3 spherical specks up to a minimum diameter of 180 μm, having statistically compatible CNR performance. The increase in substrate thickness has a substantial improvement in the CNR values provided by the Si sensor, while for the other cases the enhancement of CNR is marginal and consistent with statistical uncertainties with the thinnest case considered.
{"title":"CNR performance of semiconductor materials for X-ray imaging of breast calcifications","authors":"L. Mendoza, C. Avila, R. Rodríguez, L. Loaiza, G. Roque","doi":"10.1088/1748-0221/18/11/t11001","DOIUrl":"https://doi.org/10.1088/1748-0221/18/11/t11001","url":null,"abstract":"Abstract We present the results of a GAMOS/GEANT4 computer simulation of a standard X-ray mammography system, which consists of a Tungsten 28 kVp polychromatic X-ray source with a 50 μm Rh filter, a mammography phantom with Al 2 O 3 spherical specks of different diameters, and a generic pixel detector (55 μm × 55 μm pixel size) with different types of semiconductor sensors. The number of photons simulated is calibrated to produce similar entrance surface dose (ESD) as the one used by a standard clinical mammography screening. Estimates of Contrast to Noise Ratio (CNR) as a function of ESD, sensor thickness and microcalcification diameter are presented for four different sensor materials: Silicon (Si), Cadmium Telluride (CdTe), Gallium Arsenide (GaAs) and Perovskite (MAPbI3). For the X-ray energy spectrum and pixel size considered, and an ESD dose of 4 mGy, our study shows that, with the exception of Si, these sensors, as thin as 200 μm, are able to resolve (with at least 3 standard deviations above background) Al 2 O 3 spherical specks up to a minimum diameter of 180 μm, having statistically compatible CNR performance. The increase in substrate thickness has a substantial improvement in the CNR values provided by the Si sensor, while for the other cases the enhancement of CNR is marginal and consistent with statistical uncertainties with the thinnest case considered.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"34 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135514610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract It is known that a lithium-6 ( 6 Li) absorbs a neutron and is divided into a triton and an alpha particle. However, the trajectories of the produced tritons have not yet been imaged in real time and high resolution. We developed an ultrahigh-resolution imaging system that can clearly observe the trajectories of neutron induced particles in real time. The developed system is based on a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera combined with a 6 Li plate and a Ce-doped Gd 3 Al 2 Ga 3 O 12 (GAGG) scintillator plate. Neutrons from a californium-252 ( 252 Cf) source were irradiated to the 6 Li plate, which produced tritons and alpha particles. The produced tritons or alpha particles entered the GAGG plate and produced scintillation light along the trajectories. The scintillation trajectories were magnified by the unit, light intensified, and imaged by the EM-CCD camera. Using our system, we could measure the elongated trajectory images of the particles in real time. Most of these trajectories had Bragg peak like shapes in the images. The average range was 15 μm and the width was 4.6 μm FWHM. From the ranges we estimated, we found that these trajectories could be attributed to the induced tritons. Consequently, the developed real time imaging system is promising for research on the ultrahigh resolution imaging of neutron produced particles.
{"title":"Ultrahigh resolution real-time trajectory imaging of neutron induced particles in a scintillator from lithium-6 plate","authors":"Yamamoto Seiichi, Yoshino Masao, Nakanishi Kohei, Kamada Kei, Yoshikawa Akira, Kataoka Jun","doi":"10.1088/1748-0221/18/10/t10002","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/t10002","url":null,"abstract":"Abstract It is known that a lithium-6 ( 6 Li) absorbs a neutron and is divided into a triton and an alpha particle. However, the trajectories of the produced tritons have not yet been imaged in real time and high resolution. We developed an ultrahigh-resolution imaging system that can clearly observe the trajectories of neutron induced particles in real time. The developed system is based on a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera combined with a 6 Li plate and a Ce-doped Gd 3 Al 2 Ga 3 O 12 (GAGG) scintillator plate. Neutrons from a californium-252 ( 252 Cf) source were irradiated to the 6 Li plate, which produced tritons and alpha particles. The produced tritons or alpha particles entered the GAGG plate and produced scintillation light along the trajectories. The scintillation trajectories were magnified by the unit, light intensified, and imaged by the EM-CCD camera. Using our system, we could measure the elongated trajectory images of the particles in real time. Most of these trajectories had Bragg peak like shapes in the images. The average range was 15 μm and the width was 4.6 μm FWHM. From the ranges we estimated, we found that these trajectories could be attributed to the induced tritons. Consequently, the developed real time imaging system is promising for research on the ultrahigh resolution imaging of neutron produced particles.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134934696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We applied saturated cavity ringdown spectroscopy (CRDS) to the measurement of the Doppler-free absorption spectrum of the Balmer-α line of atomic hydrogen in an inductively coupled hydrogen plasma. The spectrum was used for estimating the electric field in the sheath region in the vicinity to a biased electrode. The absorption frequency (the absorption coefficient multiplied by the speed of light) and the saturation parameter were estimated by fitting the experimental ringdown curve with the theory reported by Giusfredi and coworkers ( Phys. Rev. Lett. 104 (2010) 110801). We detected the Lamb dip corresponding to the 2 p 2 P o 3/2 - 3 d 2 D 5/2 transition in the absorption spectrum in the field-free condition. We observed the change in the Lamb dip spectrum when we repeated the measurement in the sheath, and we succeeded in estimating the sheath electric field of 220–230 V/cm at a distance of 1.8 mm from the electrode which was biased at -100 V with respect to the ground potential. The experimental results indicate the potential of saturated CRDS for the measurement of sheath electric fields in plasmas.
{"title":"Saturated cavity ringdown spectroscopy at Balmer-α line of atomic hydrogen for estimating sheath electric field in plasma","authors":"Kimika Fushimi, Shusuke Nishiyama, Satoshi Tomioka, Koichi Sasaki","doi":"10.1088/1748-0221/18/10/c10002","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/c10002","url":null,"abstract":"Abstract We applied saturated cavity ringdown spectroscopy (CRDS) to the measurement of the Doppler-free absorption spectrum of the Balmer-α line of atomic hydrogen in an inductively coupled hydrogen plasma. The spectrum was used for estimating the electric field in the sheath region in the vicinity to a biased electrode. The absorption frequency (the absorption coefficient multiplied by the speed of light) and the saturation parameter were estimated by fitting the experimental ringdown curve with the theory reported by Giusfredi and coworkers ( Phys. Rev. Lett. 104 (2010) 110801). We detected the Lamb dip corresponding to the 2 p 2 P o 3/2 - 3 d 2 D 5/2 transition in the absorption spectrum in the field-free condition. We observed the change in the Lamb dip spectrum when we repeated the measurement in the sheath, and we succeeded in estimating the sheath electric field of 220–230 V/cm at a distance of 1.8 mm from the electrode which was biased at -100 V with respect to the ground potential. The experimental results indicate the potential of saturated CRDS for the measurement of sheath electric fields in plasmas.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135567229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10010
F. Henningsen, N. Braam, M. Danninger
Abstract This paper discusses the development of cost-effective and high-performance picosecond and high-power light pulsers. The use of innovative gallium nitride field-effect transistor technology, in combination with meticulous electronic design and careful selection of light-emitting diodes or laser diodes for ultraviolet and visible spectral ranges, has resulted in superior characteristics compared to commonly used designs. The sub-ns design achieves pulse widths as low as 300 ps, with photon outputs ranging between 10 4 -10 9 photons per pulse, over a wavelength range of 235-470 nm. Meanwhile, the high-power design achieves pulse widths as low as 1.8 ns, with photon outputs ranging between 10 7 -10 11 photons per pulse, and a wavelength range of 375-525 nm. The two designs complement each other in photon outputs, covering a dynamic range of almost ten orders of magnitude. This paper provides an evaluation of the electrical design and emitter selection of both pulsers, as well as their electrical and optical performance.
{"title":"Picosecond and high-power UV/Vis light pulsing using gallium nitride field-effect transistors: implementation and design evaluation","authors":"F. Henningsen, N. Braam, M. Danninger","doi":"10.1088/1748-0221/18/10/p10010","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10010","url":null,"abstract":"Abstract This paper discusses the development of cost-effective and high-performance picosecond and high-power light pulsers. The use of innovative gallium nitride field-effect transistor technology, in combination with meticulous electronic design and careful selection of light-emitting diodes or laser diodes for ultraviolet and visible spectral ranges, has resulted in superior characteristics compared to commonly used designs. The sub-ns design achieves pulse widths as low as 300 ps, with photon outputs ranging between 10 4 -10 9 photons per pulse, over a wavelength range of 235-470 nm. Meanwhile, the high-power design achieves pulse widths as low as 1.8 ns, with photon outputs ranging between 10 7 -10 11 photons per pulse, and a wavelength range of 375-525 nm. The two designs complement each other in photon outputs, covering a dynamic range of almost ten orders of magnitude. This paper provides an evaluation of the electrical design and emitter selection of both pulsers, as well as their electrical and optical performance.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135606308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract High-resolution and real-time imaging of the trajectories of alpha particles is desired in nuclear medicine and nuclear engineering. Although an imaging method using a scintillator plate combined with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera is a possible method of obtaining high-resolution trajectory images, the spatial resolution of the system is limited to ∼2 μm. To overcome the spatial resolution limitations of this method on trajectory imaging, we used a cooled complementally metal oxide (CMOS) camera in which the sensor had a much larger number of pixels, which were also smaller. Using the CMOS camera based imaging system, we could measure the trajectories of alpha particles in real time with the spatial resolution of 0.34 μm FWHM. With smoothing of the images to reduce image noise, spatial resolution was still kept to less than 0.75 μm. We conclude that this CMOS camera-based alpha-particle trajectory-imaging system is promising for alpha-particle or other particles imaging where ultrahigh spatial resolution is required.
{"title":"Sub-micrometer real-time imaging of trajectory of alpha particles using GAGG plate and CMOS camera","authors":"Seiichi Yamamoto, Masao Yoshino, Kohei Nakanishi, Katsunori Yogo, Kei Kamada, Akira Yoshikawa, Nanase Koshikawa, Jun Kataoka","doi":"10.1088/1748-0221/18/10/t10003","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/t10003","url":null,"abstract":"Abstract High-resolution and real-time imaging of the trajectories of alpha particles is desired in nuclear medicine and nuclear engineering. Although an imaging method using a scintillator plate combined with a magnifying unit and a cooled electron multiplying charge-coupled device (EM-CCD) camera is a possible method of obtaining high-resolution trajectory images, the spatial resolution of the system is limited to ∼2 μm. To overcome the spatial resolution limitations of this method on trajectory imaging, we used a cooled complementally metal oxide (CMOS) camera in which the sensor had a much larger number of pixels, which were also smaller. Using the CMOS camera based imaging system, we could measure the trajectories of alpha particles in real time with the spatial resolution of 0.34 μm FWHM. With smoothing of the images to reduce image noise, spatial resolution was still kept to less than 0.75 μm. We conclude that this CMOS camera-based alpha-particle trajectory-imaging system is promising for alpha-particle or other particles imaging where ultrahigh spatial resolution is required.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135656898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/p10011
Peifeng Yu, Jie Cheng, Minwen Tang, Feng lin, Zezhan Zhang, Shan Gao, Yi Niu, Chao Wang, Jing Jiang
Abstract To address the challenge of obtaining key device strain parameters within narrow spaces, this paper presents the design of a small-sized optical imaging probe with an independent optical system based on the basic principle of digital image correlation (DIC). To validate the strain measurement accuracy of the probe, a high-temperature heating system was built under in a laboratory setting, and experimental tests involving room temperature strain measurement and high temperature thermal expansion coefficient measurement were conducted. The findings demonstrate the potential of the developed probe for strain measurement in critical components situated in restricted spaces.
{"title":"Design and application testing of imaging probe for strain measurement","authors":"Peifeng Yu, Jie Cheng, Minwen Tang, Feng lin, Zezhan Zhang, Shan Gao, Yi Niu, Chao Wang, Jing Jiang","doi":"10.1088/1748-0221/18/10/p10011","DOIUrl":"https://doi.org/10.1088/1748-0221/18/10/p10011","url":null,"abstract":"Abstract To address the challenge of obtaining key device strain parameters within narrow spaces, this paper presents the design of a small-sized optical imaging probe with an independent optical system based on the basic principle of digital image correlation (DIC). To validate the strain measurement accuracy of the probe, a high-temperature heating system was built under in a laboratory setting, and experimental tests involving room temperature strain measurement and high temperature thermal expansion coefficient measurement were conducted. The findings demonstrate the potential of the developed probe for strain measurement in critical components situated in restricted spaces.","PeriodicalId":16184,"journal":{"name":"Journal of Instrumentation","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135663098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1088/1748-0221/18/10/c10019
S.B. Gong, T.C. Zhang, W.P. Guo, Z.P. Hou, W.Y. Zhai, C.H. Liu, B.H. Deng, Z.B. Shi, W. Chen, W.L. Zhong, M. Xu, X.R. Duan
Abstract The edge Thomson scattering (ETS) diagnostic with compact polychromators on the HL-3 Tokamak was developed recently. The energy and repetition frequency of the Nd: YAG laser are 2.0 J and 30 Hz, respectively. The laser beam propagates vertically through the plasma region and the scattered light is observed horizontally. The projected scattering region at the plasma midplane is from 0.6 < r/a < 1.0. The 5-channel compact polychromator (width 432 mm, depth 472 mm and height 88 mm) is developed to measure the Thomson scattering spectra. Modular design in the power supply and the amplifier circuits simplifies the assembly and maintenance of the polychromator. By using the new narrow band filters with cut-off depth larger than OD 4, the stray light resulted from Nd: YAG laser has been suppressed by the polychromator. The signal to noise ratio (SNR) range of each channel is from 10 to 200 depending on plasma parameters. The designed electron temperature measurement range is from 5 to 1000 eV and electron density measurement range is from 5 × 10 18 to 1 × 10 20 m -3 . New measurement results of electron temperature by ETS are compared with that from the electron cyclotron emission (ECE) radiometer. The time evolution of ETS and ECE matches with each other in different plasma discharges. Combined with the data from the core Thomson scattering diagnostic system, the plasma electron temperature profile on the HL-3 tokamak is presented for the first time.
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