Article
Chemistry, Multidisciplinary
Jun Soo Han, Sang Heon Lee, Hanbin Go, Soo Jin Kim, Jun Hong Noh, Cheol Jin Lee
Summary: A cold cathode X-ray tube utilizing a carbon nanotube field emitter was developed, exhibiting high tube current density, high electron beam transmittance, and small focal spot size. Additionally, the tube showed stable lifetime and can be widely used in various X-ray applications in the future.
Article
Chemistry, Physical
Yujung Ahn, Seong Jun Kim, Jin-Woo Jeong, Sora Park, Jae-Woo Kim, Eunsol Go, Jeong-Woong Lee, Jun-Tae Kang, Ki Nam Yun, Sunghoon Choi, Sunghee Kim, Ji-Hwan Yeon, Yoon-Ho Song
Summary: Field-emitted electron beams from nanometer-scale materials like carbon nanotubes (CNTs) have the potential to regenerate electron source devices. Digital X-ray tubes fabricated with CNT paste-emitters can produce short and exact X-ray pulses, enhancing X-ray images with minimal dose.
Article
Materials Science, Multidisciplinary
Weijun Huang, Yunmi Huang, Ruizi Liu, Wei Zhu, Song Kang, Weijin Qian, Changkun Dong
Summary: A micro-focus X-ray source with a miniature pressure sensor based on multi-walled carbon nanotube field emission was developed. The source demonstrated high-resolution X-ray imaging of practical objects, and the pressure sensor successfully monitored in-situ pressures inside the source.
DIAMOND AND RELATED MATERIALS
(2022)
Correction
Materials Science, Multidisciplinary
Xinchuan Liu, Yuanxun Li, Jianfeng Xiao, Jiuzhou Zhao, Chi Li, Zhenjun Li
Summary: The study investigates the field emission stability of vertically aligned carbon nanotubes through anchoring for X-ray imaging applications. The results demonstrate that anchoring plays a crucial role in enhancing the field emission performance and stability of carbon nanotubes.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Philip Mosel, Pranitha Sankar, Jan Friedrich Duesing, Guenter Dittmar, Thomas Puester, Peter Jaeschke, Jan-Willem Vahlbruch, Uwe Morgner, Milutin Kovacev
Summary: Ultrashort pulse laser machining can increase X-ray radiation dose rates, especially in the energy range below 10 keV. Our experiments show that the X-ray dose rates for high repetition rate lasers exceed legal limitations in the absence of radiation shielding.
Article
Materials Science, Multidisciplinary
Sheng Lai, Yunpeng Liu, Junxu Mu, Zhaopeng Feng, Kai Miao, Xiaobin Tang
Summary: In this study, we constructed a triode structure of carbon nanotube (CNT) cold cathode X-ray source driven by pulse voltage in a dynamic vacuum system. The results indicated that the grid voltage and pulse width had an impact on the amplitude, delay time, and relative pulse spread of the X-ray. The research revealed the ultra-short pulse emission characteristics and influencing factors of the CNT cold cathode X-ray source, thereby promoting its development in pulse applications.
Article
Engineering, Electrical & Electronic
Amar Prasad Gupta, Seung Jun Yeo, Mallory Mativenga, Jaeik Jung, Wooseob Kim, Jongmin Lim, Junyoung Park, Jeung Sun Ahn, Seung Hoon Kim, Moon Shik Chae, Yeong Heum Yeon, Namkug Kim, Beom-Seok Ko, Jehwang Ryu
Summary: When breast cancer is surgically removed, a rim of normal tissue surrounding the tumor is also removed, which is studied by a pathologist to determine whether or not all tumor was removed. This study investigates the feasibility of using a portable carbon nanotube (CNT)-based X-ray system for in situ detection of tumor cells in the surgical margin, showing promising potential for next-generation pathological examinations.
INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY
(2021)
Article
Optics
Yinren Shou, Pengjie Wang, Seong Geun Lee, Yong Joo Rhee, Hwang Woon Lee, Jin Woo Yoon, Jae Hee Sung, Seong Ku Lee, Zhuo Pan, Defeng Kong, Zhusong Mei, Jianbo Liu, Shirui Xu, Zhigang Deng, Weimin Zhou, Toshiki Tajima, Il Woo Choi, Xueqing Yan, Chang Hee Nam, Wenjun Ma
Summary: Brilliant X- and gamma-ray sources with ultrashort duration are widely pursued. Compact femtosecond X-ray sources based on relativistic electrons accelerated by the laser wakefield in gases have limitations in energy conversion efficiency. This study reports high-yield generation of hard X-ray flashes from carbon nanotube targets, resulting in an unprecedented efficiency. With upcoming 10-PW-class lasers, these targets can deliver 10-MeV photons with brightness outperforming existing sources by two orders of magnitude.
Article
Chemistry, Multidisciplinary
Helin Zhu, Jejin Jang, Gyuwan Im, Hyungsoo Mok, Jehwang Ryu, Kyung-Seo Kim
Summary: Further studies on the suitability, dynamic characteristics, and applications of carbon nanotubes in high-frequency pulsing of X-rays are needed. This study analyzes the combined dynamics of field emission, MOSFET, and a modified gate driver for MOSFET, and proposes a modified gate driver structure to accurately control the tube current and enhance the dynamic current performance of carbon nanotube tubes.
Article
Chemistry, Multidisciplinary
Bishwa Chandra Adhikari, Bhotkar Ketan, Ju Sung Kim, Sung Tae Yoo, Eun Ha Choi, Kyu Chang Park
Summary: This study successfully achieved the goal of measuring the spot of high-density electron beams under the variation of voltage and exposure time by fabricating vertically aligned carbon nanotube emitters. By capturing microimages on a microchannel plate and analyzing the morphology structures using scanning electron microscopy, the researchers obtained measurements of the high-density electron beam and demonstrated that this configuration is applicable to high-resolution multi-beam electron microscopy and high-resolution X-ray imaging technology.
Article
Chemistry, Multidisciplinary
Sung Tae Yoo, Kyu Chang Park
Summary: In this article, a novel method of EUV generation by irradiating Sn with electrons emitted from a carbon nanotube-based cold cathode electron beam was demonstrated. The intensity of EUV can be controlled by the number of emitted electrons. This method has significant implications for advanced lithography for semiconductor fabrication and high-resolution photonics.
Article
Astronomy & Astrophysics
P. Zhang, W. Wang, Y. Su, L. M. Song, C. K. Li, D. K. Zhou, S. N. Zhang, H. Tian, S. M. Liu, H. S. Zhao, S. Zhang
Summary: The article reports on the observation of an X9.3 flare by the first Chinese X-ray observatory, Insight-HXMT, using wavelets to detect 22-second quasi-periodic pulsations. Spectral analysis shows the evolution of non-thermal electron density and magnetic field strength over time, indicating that the non-thermal electrons may originate from a lower corona source.
ASTROPHYSICAL JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Jiangtao Chen, Xinyao Chang, Shaodan Wu, Hui Ren, Yirun Zhu, Bingjun Yang, Yun Zhao, Jianbiao Chen, Yan Li
Summary: High performance cold cathodes based on carbon nanotubes (CNTs) are fabricated using a screen-printing method. The CNT cathode exhibits stable electron emission and the temperature-dependent emission is also investigated. Results show that the CNT emitters achieve a maximum emission current of 16.9 mA and a super-high current density of 562 mA cm-2 under continuous driving mode, and a peak current of 70 mA with a high current density of 2333 mA cm-2 under pulse driving mode. This work provides a new approach for designing double-high CNT cold electron sources for vacuum electronic devices requiring high current and density simultaneously.
Article
Chemistry, Analytical
Changkun Dong, Ruizi Liu, Jie Wang, Haipeng Yu, Song Kang, Weijun Huang, Weikang Jia, Weijin Qian
Summary: A novel low pressure helium sensing method using carbon nanotube field emission has been developed, showing promising applications in leak detection. By analyzing the field emission currents from multi-walled carbon nanotubes with low crystallinities, it was found that the work functions of CNT emitters remained consistent with helium adsorptions. The simulation results showed that adsorption of helium atoms on carbon atoms at defects enhanced the field emission current, enabling the detection of helium gas.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Materials Science, Multidisciplinary
K. Hareesh, Sachin R. Rondiya, S. D. Dhole, M. A. More, D. M. Phase
Summary: Through comparison experiments, it was found that the CoFe2O4/rGO/CNT emitter has higher current density and emission stability compared to other types of emitters, due to its reduced bandgap and work function, as well as sharp edges provided for easy electron liberation.
