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1,749 results on '"Li, J. H."'

1. Characteristics of the MTx optical transmitter in Total Ionizing Dose

Author

Gong, D., Hou, S., Juang, B. J., Li, J. -H., Liu, C., Liu, T., Qi, M., Ye, J., Zhang, Lei, Zhang, Li, and Zhu, H. P.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The dual-channel multi-mode 850 nm optical Miniature Transmitter (MTx) is developed for data transmission of the ATLAS LAr calorimeter readout at LHC. The MTx's are exposed to the radiation field of proton-proton collisions, therefore, the tolerance in Total Ionizing Dose (TID) is required. The TID effects in the MTx are investigated with X-rays and Co-60 gamma-rays for the active components of VCSEL diodes and the customized Link-on-Chip laser driver (LOCld) developed in 0.25 um Silicon-on-Sapphire CMOS technology. The irradiation tests were conducted at various dose rates. The responses to TID are observed with degradation of laser currents at initial dose of 10 to 100 Gy(SiO2), and partial recovery with additional TID to a stable output about 90 % of the original. The optical eye diagrams of irradiated samples show slightly increased jittering, and are suitable for the ATLAS requirement of 5 Gbps applications., Comment: 7 pages, 10 figures

Published
2024

2. Performance of the CMS High Granularity Calorimeter prototype to charged pion beams of 20$-$300 GeV/c

Author

Acar, B., Adamov, G., Adloff, C., Afanasiev, S., Akchurin, N., Akgün, B., Alhusseini, M., Alison, J., de Almeida, J. P. Figueiredo de sa Sousa, de Almeida, P. G. Dias, Alpana, A., Alyari, M., Andreev, I., Aras, U., Aspell, P., Atakisi, I. O., Bach, O., Baden, A., Bakas, G., Bakshi, A., Banerjee, S., DeBarbaro, P., Bargassa, P., Barney, D., Beaudette, F., Beaujean, F., Becheva, E., Becker, A., Behera, P., Belloni, A., Bergauer, T., Berni, M. El, Besancon, M., Bhattacharya, S., Bhowmik, D., Bilki, B., Bilokin, S., Blazey, G. C., Blekman, F., Bloch, P., Bodek, A., Bonanomi, M., Bonis, J., Bonnemaison, A., Bonomally, S., Borg, J., Bouyjou, F., Bower, N., Braga, D., Brennan, L., Brianne, E., Brondolin, E., Bryant, P., Buhmann, E., Buhmann, P., Butler-Nalin, A., Bychkova, O., Callier, S., Calvet, D., Canderan, K., Cankocak, K., Cao, X., Cappati, A., Caraway, B., Caregari, S., Carty, C., Cauchois, A., Ceard, L., Cerci, D. S., Cerci, S., Cerminara, G., Chadeeva, M., Charitonidis, N., Chatterjee, R., Chen, J. A., Chen, Y. M., Cheng, H. J., Cheng, K. Y., Cheung, H., Chokheli, D., Cipriani, M., Čoko, D., Couderc, F., Cuba, E., Danilov, M., Dannheim, D., Daoud, W., Das, I., Dauncey, P., Davies, G., Davignon, O., Day, E., Debbins, P., Defranchis, M. M., Delagnes, E., Demiragli, Z., Demirbas, U., Derylo, G., Diaz, D., Diehl, L., Dinaucourt, P., Dincer, G. G., Dittmann, J., Dragicevic, M., Dugad, S., Dulucq, F., Dumanoglu, I., Dünser, M., Dutta, S., Dutta, V., Edberg, T. K., Elias, F., Emberger, L., Eno, S. C., Ershov, Yu., Extier, S., Fahim, F., Fallon, C., Fard, K. Sarbandi, Fedi, G., Ferragina, L., Forthomme, L., Frahm, E., Franzoni, G., Freeman, J., French, T., Gadow, K., Gandhi, P., Ganjour, S., Gao, X., Garcia, M. T. Ramos, Garcia-Bellido, A., Garutti, E., Gastaldi, F., Gastler, D., Gecse, Z., Germer, A., Gerwig, H., Gevin, O., Ghosh, S., Gilbert, A., Gilbert, W., Gill, K., Gingu, C., Gninenko, S., Golunov, A., Golutvin, I., Gonultas, B., Gorbounov, N., Göttlicher, P., Gouskos, L., Graf, C., Gray, A. B., Grieco, C., Gr\"önroos, S., Gu, Y., Guilloux, F., Guler, E. Gurpinar, Guler, Y., Gülmez, E., Guo, J., Gutti, H., Hakimi, A., Hammer, M., Hartbrich, O., Hassanshahi, H. M., Hatakeyama, K., Hazen, E., Heering, A., Hegde, V., Heintz, U., Heuchel, D., Hinton, N., Hirschauer, J., Hoff, J., Hou, W. S., Hou, X., Hua, H., Huck, S., Hussain, A., Incandela, J., Irles, A., Irshad, A., Isik, C., Jain, S., Jaroslavceva, J., Jheng, H. R., Joshi, U., Kaadze, K., Kachanov, V., Kalipoliti, L., Kaminskiy, A., Kanuganti, A. R., Kao, Y. W., Kapoor, A., Kara, O., Karneyeu, A., Kałuzińska, O., Kaya, M., Kaya, O., Kazhykharim, Y., Khan, F. A., Khukhunaishvili, A., Kieseler, J., Kilpatrick, M., Kim, S., Koetz, K., Kolberg, T., Komm, M., Köseyan, O. K., Kraus, V., Krawczyk, M., Kristiansen, K., Kristić, A., Krohn, M., Kronheim, B., Krüger, K., Kulis, S., Kumar, M., Kunori, S., Kuo, C. M., Kuryatkov, V., Kvasnicka, J., Kyre, S., Lai, Y., Lamichhane, K., Landsberg, G., Lange, C., Langford, J., Laurien, S., Lee, M. Y., Lee, S. W., Leiton, A. G. Stahl, Levin, A., Li, A., Li, J. H., Li, Y. Y., Liang, Z., Liao, H., Lin, Z., Lincoln, D., Linssen, L., Lipton, R., Liu, G., Liu, Y., Lobanov, A., Lohezic, V., Lomidze, D., Lu, R. S., Lu, S., Lupi, M., Lysova, I., Magnan, A. -M., Magniette, F., Mahjoub, A., Martens, S., Matysek, M., Meier, B., Malakhov, A., Mallios, S., Mandjavize, I., Mannelli, M., Mans, J., Marchioro, A., Martelli, A., Martinez, G., Masterson, P., Matthewman, M., Mayekar, S. N., David, A., Coco, S., Meng, B., Menkel, A ., Mestvirishvili, A., Milella, G., Mirza, I., Moccia, S., Mohanty, G. B., Monti, F., Moortgat, F. W., Morrissey, I., Motta, J., Murthy, S., Musić, J., Musienko, Y., Nabili, S., Nguyen, M., Nikitenko, A., Noonan, D., Noy, M., Nurdan, K., Nursanto, M. Wulansatiti, Ochando, C., Odell, N., Okawa, H., Onel, Y., Ortez, W., Ozegović, J., Ozkorucuklu, S., Paganis, E., Palmer, C. A., Pandey, S., Pantaleo, F., Papageorgakis, C., Papakrivopoulos, I., Paranjpe, M., Parshook, J., Pastika, N., Paulini, M., Peitzmann, T., Peltola, T., Peng, N., Perraguin, A. Buchot, Petiot, P., Pierre-Emile, T., Pinto, M. Vicente Barreto, Popova, E., Pöschl, R., Prosper, H., Prvan, M., Puljak, I., Qasim, S. R., Qu, H., Quast, T., Quinn, R., Quinnan, M., Rane, A., Rao, K. K., Rapacz, K., Raux, L., Redjeb, W., Reinecke, M., Revering, M., Richard, F., Roberts, A., Sanchez, A. M., Rohlf, J., Rolph, J., Romanteau, T., Rosado, M., Rose, A., Rovere, M., Roy, A., Rubinov, P., Rusack, R., Rusinov, V., Ryjov, V., Sahin, O. M., Salerno, R., Saradhy, R., Sarkar, T., Sarkisla, M. A., Sauvan, J. B., Schmidt, I., Schmitt, M., Schuwalow, S., Scott, E., Seez, C., Sefkow, F., Selivanova, D., Sharma, S., Shelake, M., Shenai, A., Shukla, R., Sicking, E., De, M., Silva, P., Simkina, P., Simon, F., Simsek, A. E., Sirois, Y., Smirnov, V., Sobering, T. J., Spencer, E., Srimanobhas, N., Steen, A., Strait, J., Strobbe, N., Su, X. F., Sudo, Y., Suarez, C. Mantilla, Sukhov, E., Sulak, L., Sun, L., Suryadevara, P., Syal, C., de La Taille, C., Tali, B., Tan, C. L., Tao, J., Tarabini, A., Tatli, T., Thaus, R., Taylor, R. D., Tekten, S., Thiebault, A., Thienpont, D., Tiley, C., Tiras, E., Titov, M., Tlisov, D., Tok, U. G., Kayis, A., Troska, J., Tsai, L. S., Tsamalaidze, Z., Tsipolitis, G., Tsirou, A., Undleeb, S., Urbanski, D., Uslan, E., Ustinov, V., Uzunian, A., Varela, J., Velasco, M., Vernazza, E., Viazlo, O., Vichoudis, P., Virdee, T., Voirin, E., Vojinovi\c, M., Vojinovic, M., Wade, A., Wang, C., Wang, C. C., Wang, D., Wang, F., Wang, X., Wang, Z., Wayne, M., Webb, S. N., Whitbeck, A., Wickwire, R., Wilson, J. S., Wu, H. Y., Wu, L., Xiao, M., Yang, J., Yeh, C. H, Yohay, R., Yu, D., Yu, S. S., Yuan, C., Miao, Y., Yumiceva, F., Yusuff, I., Zabi, A., Zacharopoulou, A., Zamiatin, N., Zarubin, A., Zehetner, P., Zerwas, D., Zhang, H., Zhang, J., Zhang, Y., Zhang, Z., and Zhao, X.

Subjects
Physics - Instrumentation and Detectors
Abstract

The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly readout by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data., Comment: Accepted for publication by JINST

Published
2022

3. GECAM detection of a bright type-I X-ray burst from 4U 0614+09: confirmation its spin frequency at 413 Hz

Author

Chen, Y. P., Li, J., Xiong, S. L., Ji, L., Zhang, S., Peng, W. X., Qiao, R., Li, X. Q., Wen, X. Y., Song, L. M., Zheng, S. J., Song, X. Y., Zhao, X. Y., Huang, Y., Lu, F. J., Zhang, S. N., Xiao, S., Cai, C., Zhang, B. X., An, Z. H., Chen, C., Chen, G., Chen, W., Dai, G. Q., Du, Y. Q., Gao, M., Gong, K., Guo, D. Y., Guo, Z. W., He, J. J., Li, B., Li, C., Li, C. Y., Li, G., Li, J. H., Li, L., Li, Q. X., Li, X. B., Li, Y. G., Liang, J., Liang, X. H., Liao, J. Y., Liu, J. C., Liu, X. J., Liu, Y. Q., Luo, Q., Ma, X., Meng, B., Ou, G., Shi, D. L., Shi, F., Shi, J. Y., Sun, G. X., Sun, X. L., Tuo, Y. L., Wang, C. W., Wang, H., Wang, H. Y., Wang, J., Wang, J. Z., Wang, P., Wang, Y. S., Wang, Y. X., Wen, X., Wu, H., Xie, S. L., Xu, Y. B., Xu, Y. P., Xue, W. C., Yang, S., Yao, M., Ye, J. Y., Yi, Q. B., Zhang, C. M., Zhang, C. Y., Zhang, D. L., Zhang, Fan, Zhang, Fei, Zhang, H. M., Zhang, K., Zhang, P., Zhang, X. L., Zhang, Y. Q., Zhang, Z., Zhao, G. Y., Zhao, S. Y., Zhao, Y., Zheng, C., Zhou, X., and Zhu, Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

One month after launching Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM), a bright thermonuclear X-ray burst from 4U~0614+09, was observed on January 24, 2021. We report the time-resolved spectroscopy of the burst and a burst oscillation detection at 413 Hz with a fractional amplitude 3.4\% (rms). This coincides with the burst oscillation previously discovered with \textit{Swift}/BAT \citep{Strohmayer2008}, and therefore confirms the spin frequency of this source. This burst is the brightest one in the normal bursts (except the superburst) ever detected from 4U~0614+09, which leads to an upper limit of distance estimation as 3.1 kpc. The folded light curve during the burst oscillation shows a multi-peak structure, which is the first case observed during a single burst oscillation in nonpulsating sources. The multi-peak profile could be due to additional harmonics of the burst oscillation, which is corresponding to several brighter/fainter spots at the stellar surface.

Published
2021
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4. Response of a CMS HGCAL silicon-pad electromagnetic calorimeter prototype to 20-300 GeV positrons

Author

Acar, B., Adamov, G., Adloff, C., Afanasiev, S., Akchurin, N., Akgün, B., Khan, F. Alam, Alhusseini, M., Alison, J., Alpana, A., Altopp, G., Alyari, M., An, S., Anagul, S., Andreev, I., Aspell, P., Atakisi, I. O., Bach, O., Baden, A., Bakas, G., Bakshi, A., Bannerjee, S., Bargassa, P., Barney, D., Beaudette, F., Beaujean, F., Becheva, E., Becker, A., Behera, P., Belloni, A., Bergauer, T., Besancon, M., Bhattacharya, S., Bhowmik, D., Bilki, B., Bloch, P., Bodek, A., Bonanomi, M., Bonnemaison, A., Bonomally, S., Borg, J., Bouyjou, F., Bower, N., Braga, D., Brashear, J., Brondolin, E., Bryant, P., Perraguin, A. Buchot, Bueghly, J., Burkle, B., Butler-Nalin, A., Bychkova, O., Callier, S., Calvet, D., Cao, X., Cappati, A., Caraway, B., Caregari, S., Cauchois, A., Ceard, L., Cekmecelioglu, Y. C., Cerci, S., Cerminara, G., Chadeeva, M., Charitonidis, N., Chatterjee, R., Chen, Y. M., Chen, Z., Cheng, H. J., Cheng, K. y., Chernichenko, S., Cheung, H., Chien, C. H., Choudhury, S., Čoko, D., Collura, G., Couderc, F., Danilov, M., Dannheim, D., Daoud, W., Dauncey, P., David, A., Davies, G., Davignon, O., Day, E., DeBarbaro, P., De Guio, F., de La Taille, C., De Silva, M., Debbins, P., Defranchis, M. M., Delagnes, E., Berrio, J. M. Deltoro, Derylo, G., de Almeida, P. G. Dias, Diaz, D., Dinaucourt, P., Dittmann, J., Dragicevic, M., Dugad, S., Dulucq, F., Dumanoglu, I., Dutta, V., Dutta, S., Dünser, M., Eckdahl, J., Edberg, T. K., Berni, M. El, Elias, F., Eno, S. C., Ershov, Yu., Everaerts, P., Extier, S., Fahim, F., Fallon, C., Fedi, G., Alves, B. A. Fontana Santos, Frahm, E., Franzoni, G., Freeman, J., French, T., Gandhi, P., Ganjour, S., Gao, X., Garcia-Bellido, A., Gastaldi, F., Gecse, Z., Geerebaert, Y., Gerwig, H., Gevin, O., Ghosh, S., Gilbert, A., Gilbert, W., Gill, K., Gingu, C., Gninenko, S., Golunov, A., Golutvin, I., Gonzalez, T., Gorbounov, N., Gouskos, L., Gray, A. B., Gu, Y., Guilloux, F., Guler, Y., Gülmez, E., Guo, J., Guler, E. Gurpinar, Hammer, M., Hassanshahi, H. M., Hatakeyama, K., Heering, A., Hegde, V., Heintz, U., Hinton, N., Hirschauer, J., Hoff, J., Hou, W. -S., Hou, X., Hua, H., Incandela, J., Irshad, A., Isik, C., Jain, S., Jheng, H. R., Joshi, U., Kachanov, V., Kalinin, A., Kalipoliti, L., Kaminskiy, A., Kapoor, A., Kara, O., Karneyeu, A., Kaya, M., Kaya, O., Topaksu, A. Kayis, Khukhunaishvili, A., Kiesler, J., Kilpatrick, M., Kim, S., Koetz, K., Kolberg, T., Köseyan, O. K., Kristić, A., Krohn, M., Krüger, K., Kulagin, N., Kulis, S., Kunori, S., Kuo, C. M., Kuryatkov, V., Kyre, S., Lai, Y., Lamichhane, K., Landsberg, G., Lange, C., Langford, J., Lee, M. Y., Levin, A., Li, A., Li, B., Li, J. H., Li, Y. y., Liao, H., Lincoln, D., Linssen, L., Lipton, R., Liu, Y., Lobanov, A., Lu, R. -S., Lupi, M., Lysova, I., Magnan, A. -M., Magniette, F., Mahjoub, A., Maier, A. A., Malakhov, A., Mallios, S., Mandjavize, I., Mannelli, M., Mans, J., Marchioro, A., Martelli, A., Martinez, G., Masterson, P., Meng, B., Mengke, T., Mestvirishvili, A., Mirza, I., Moccia, S., Mohanty, G. B., Monti, F., Morrissey, I., Murthy, S., Musić, J., Musienko, Y., Nabili, S., Nagar, A., Nguyen, M., Nikitenko, A., Noonan, D., Noy, M., Nurdan, K., Ochando, C., Odegard, B., Odell, N., Okawa, H., Onel, Y., Ortez, W., Ozegović, J., Ozkorucuklu, S., Paganis, E., Pagenkopf, D., Palladino, V., Pandey, S., Pantaleo, F., Papageorgakis, C., Papakrivopoulos, I., Parshook, J., Pastika, N., Paulini, M., Paulitsch, P., Peltola, T., Gomes, R. Pereira, Perkins, H., Petiot, P., Pierre-Emile, T., Pitters, F., Popova, E., Prosper, H., Prvan, M., Puljak, I., Qu, H., Quast, T., Quinn, R., Quinnan, M., Garcia, M. T. Ramos, Rao, K. K., Rapacz, K., Raux, L., Reichenbach, G., Reinecke, M., Revering, M., Roberts, A., Romanteau, T., Rose, A., Rovere, M., Roy, A., Rubinov, P., Rusack, R., Rusinov, V., Ryjov, V., Sahin, O. M., Salerno, R., Rodriguez, A. M. Sanchez, Saradhy, R., Sarkar, T., Sarkisla, M. A., Sauvan, J. B., Schmidt, I., Schmitt, M., Scott, E., Seez, C., Sefkow, F., Sharma, S., Shein, I., Shenai, A., Shukla, R., Sicking, E., Sieberer, P., Silva, P., Simsek, A. E., Sirois, Y., Smirnov, V., Sozbilir, U., Spencer, E., Steen, A., Strait, J., Strobbe, N., Su, J. W., Sukhov, E., Sun, L., Cerci, D. Sunar, Syal, C., Tali, B., Tan, C. L., Tao, J., Tastan, I., Tatli, T., Thaus, R., Tekten, S., Thienpont, D., Tiras, E., Titov, M., Tlisov, D., Tok, U. G., Troska, J., Tsai, L. -S., Tsamalaidze, Z., Tsipolitis, G., Tsirou, A., Tyurin, N., Undleeb, S., Urbanski, D., Ustinov, V., Uzunian, A., Van de Klundert, M., Varela, J., Velasco, M., Viazlo, O., Pinto, M. Vicente Barreto, Virdee, P. Vichoudis T., de Oliveira, R. Vizinho, Voelker, J., Voirin, E., Vojinovic, M., Wade, A., Wang, C., Wang, F., Wang, X., Wang, Z., Wayne, M., Webb, S. N., Whitbeck, A., White, D., Wickwire, R., Wilson, J. S., Winter, D., Wu, H. y., Wu, L., Nursanto, M. Wulansatiti, Yeh, C. H, Yohay, R., Yu, D., Yu, G. B., Yu, S. S., Yuan, C., Yumiceva, F., Yusuff, I., Zacharopoulou, A., Zamiatin, N., Zarubin, A., Zenz, S., Zghiche, A., Zhang, H., Zhang, J., Zhang, Y., and Zhang, Z.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The Compact Muon Solenoid Collaboration is designing a new high-granularity endcap calorimeter, HGCAL, to be installed later this decade. As part of this development work, a prototype system was built, with an electromagnetic section consisting of 14 double-sided structures, providing 28 sampling layers. Each sampling layer has an hexagonal module, where a multipad large-area silicon sensor is glued between an electronics circuit board and a metal baseplate. The sensor pads of approximately 1 cm$^2$ are wire-bonded to the circuit board and are readout by custom integrated circuits. The prototype was extensively tested with beams at CERN's Super Proton Synchrotron in 2018. Based on the data collected with beams of positrons, with energies ranging from 20 to 300 GeV, measurements of the energy resolution and linearity, the position and angular resolutions, and the shower shapes are presented and compared to a detailed Geant4 simulation.

Published
2021
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5. Quantum fluctuations of charge order induce phonon softening in a superconducting cuprate

Author

Huang, H. Y., Singh, A., Mou, C. Y., Johnston, S., Kemper, A. F., Brink, J. van den, Chen, P. J., Lee, T. K., Okamoto, J., Chu, Y. Y., Li, J. H., Komiya, S., Komarek, A. C., Fujimori, A., Chen, C. T., and Huang, D. J.

Subjects
Condensed Matter - Superconductivity
Abstract

Quantum phase transitions play an important role in shaping the phase diagram of high-temperature cuprate superconductors. These cuprates possess intertwined orders which interact strongly with superconductivity. However, the evidence for the quantum critical point associated with the charge order in the superconducting phase remains elusive. Here we show the short-range charge orders and the spectral signature of the quantum fluctuations in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) near the optimal doping using high-resolution resonant inelastic X-ray scattering. On performing calculations through a diagrammatic framework, we discovered that the charge correlations significantly soften several branches of phonons. These results elucidate the role of charge order in the LSCO compound, providing evidence for quantum critical scaling and discommensurations associated with charge order., Comment: 9 pages, 4 figures

Published
2021
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6. Effect of Die Coating on Friction Behavior of 7075 Aluminum Alloy Sheet in Hot Stamping

Author

Wang, Y. P., Wang, Y. L., Li, J. H., Zhang, Y. S., Xiao, Shengxiong, Editor-in-Chief, Bassir, David, Series Editor, Gao, Bingbing, Series Editor, Jiang, Yongchao, Series Editor, Li, Jia, Series Editor, Mazumdar, Sayantan, Series Editor, Sun, Qijun, Series Editor, Tang, Juntao, Series Editor, Xiong, Chuanyin, Series Editor, Xu, Hexiu, Series Editor, Yang, Jun, Series Editor, Zhang, Yisheng, editor, and Ma, Mingtu, editor

Published
2023
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7. Construction and commissioning of CMS CE prototype silicon modules

Author

Acar, B., Adamov, G., Adloff, C., Afanasiev, S., Akchurin, N., Akgün, B., Alhusseini, M., Alison, J., Altopp, G., Alyari, M., An, S., Anagul, S., Andreev, I., Andrews, M., Aspell, P., Atakisi, I. A., Bach, O., Baden, A., Bakas, G., Bakshi, A., Bargassa, P., Barney, D., Becheva, E., Behera, P., Belloni, A., Bergauer, T., Besancon, M., Bhattacharya, S., Bhowmik, D., Bloch, P., Bodek, A., Bonanomi, M., Bonnemaison, A., Bonomally, S., Borg, J., Bouyjou, F., Braga, D., Brashear, J., Brondolin, E., Bryant, P., Bueghly, J., Bilki, B., Burkle, B., Butler-Nalin, A., Callier, S., Calvet, D., Cao, X., Caraway, B., Caregari, S., Ceard, L., Cekmecelioglu, Y. C., Cerminara, G., Charitonidis, N., Chatterjee, R., Chen, Y. M., Chen, Z., Cheng, K. y., Chernichenko, S., Cheung, H., Chien, C. H., Choudhury, S., Čoko, D., Collura, G., Couderc, F., Dumanoglu, I., Dannheim, D., Dauncey, P., David, A., Davies, G., Day, E., DeBarbaro, P., De Guio, F., de La Taille, C., De Silva, M., Debbins, P., Delagnes, E., Deltoro, J. M., Derylo, G., de Almeida, P. G. Dias, Diaz, D., Dinaucourt, P., Dittmann, J., Dragicevic, M., Dugad, S., Dutta, V., Dutta, S., Eckdahl, J., Edberg, T. K., Berni, M. El, Eno, S. C., Ershov, Yu., Everaerts, P., Extier, S., Fahim, F., Fallon, C., Alves, B. A. Fontana Santos, Frahm, E., Franzoni, G., Freeman, J., French, T., Guler, E. Gurpinar, Guler, Y., Gagnan, M., Gandhi, P., Ganjour, S., Garcia-Bellido, A., Gecse, Z., Geerebaert, Y., Gerwig, H., Gevin, O., Gilbert, W., Gilbert, A., Gill, K., Gingu, C., Gninenko, S., Golunov, A., Golutvin, I., Gonzalez, T., Gorbounov, N., Gouskos, L., Gu, Y., Guilloux, F., Gülmez, E., Hammer, M., Harilal, A., Hatakeyama, K., Heering, A., Hegde, V., Heintz, U., Hinger, V., Hinton, N., Hirschauer, J., Hoff, J., Hou, W. S., Isik, C., Incandela, J., Jain, S., Jheng, H. R., Joshi, U., Kara, O., Kachanov, V., Kalinin, A., Kameshwar, R., Kaminskiy, A., Karneyeu, A., Kaya, O., Kaya, M., Khukhunaishvili, A., Kim, S., Koetz, K., Kolberg, T., Kristić, A., Krohn, M., Krüger, K., Kulagin, N., Kulis, S., Kunori, S., Kuo, C. M., Kuryatkov, V., Kyre, S., Köseyan, O. K., Lai, Y., Lamichhane, K., Landsberg, G., Langford, J., Lee, M. Y., Levin, A., Li, A., Li, B., Li, J. -H., Liao, H., Lincoln, D., Linssen, L., Lipton, R., Liu, Y., Lobanov, A., Lu, R. S., Lysova, I., Magnan, A. M., Magniette, F., Maier, A. A., Malakhov, A., Mandjavize, I., Mannelli, M., Mans, J., Marchioro, A., Martelli, A., Masterson, P., Meng, B., Mengke, T., Mestvirishvili, A., Mirza, I., Moccia, S., Morrissey, I., Mudholkar, T., Musić, J., Musienko, I., Nabili, S., Nagar, A., Nikitenko, A., Noonan, D., Noy, M., Nurdan, K., Ochando, C., Odegard, B., Odell, N., Onel, Y., Ortez, W., Ozegović, J., Rodriguez, L. Pacheco, Paganis, E., Pagenkopf, D., Palladino, V., Pandey, S., Pantaleo, F., Papageorgakis, C., Papakrivopoulos, I., Parshook, J., Pastika, N., Paulini, M., Paulitsch, P., Peltola, T., Gomes, R. Pereira, Perkins, H., Petiot, P., Pitters, F., Prosper, H., Prvan, M., Puljak, I., Quast, T., Quinn, R., Quinnan, M., Rapacz, K., Raux, L., Reichenbach, G., Reinecke, M., Revering, M., Rodriguez, A., Romanteau, T., Rose, A., Rovere, M., Roy, A., Rubinov, P., Rusack, R., Simsek, A. E., Sozbilir, U., Sahin, O. M., Sanchez, A., Saradhy, R., Sarkar, T., Sarkisla, M. A., Sauvan, J. B., Schmidt, I., Schmitt, M., Scott, E., Seez, C., Sefkow, F., Sharma, S., Shein, I., Shenai, A., Shukla, R., Sicking, E., Sieberer, P., Sirois, Y., Smirnov, V., Spencer, E., Steen, A., Strait, J., Strebler, T., Strobbe, N., Su, J. W., Sukhov, E., Sun, L., Sun, M., Syal, C., Tali, B., Tok, U. G., Topaksu, A. Kayis, Tan, C. L., Tastan, I., Tatli, T., Thaus, R., Tekten, S., Thienpont, D., Pierre-Emile, T., Tiras, E., Titov, M., Tlisov, D., Troska, J., Tsamalaidze, Z., Tsipolitis, G., Tsirou, A., Tyurin, N., Undleeb, S., Urbanski, D., Ustinov, V., Uzunian, A., van de Klundert, M., Varela, J., Velasco, M., Pinto, M. Vicente Barreto, da Silva, P. M., Virdee, T., de Oliveira, R. Vizinho, Voelker, J., Voirin, E., Wang, Z., Wang, X., Wang, F., Wayne, M., Webb, S. N., Weinberg, M., Whitbeck, A., White, D., Wickwire, R., Wilson, J. S., Wu, H. Y., Wu, L., Yeh, C. H, Yohay, R., Yu, G. B., Yu, S. S., Yu, D., Yumiceva, F., Zacharopoulou, A., Zamiatin, N., Zarubin, A., Zenz, S., Zhang, H., and Zhang, J.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

As part of its HL-LHC upgrade program, the CMS Collaboration is developing a High Granularity Calorimeter (CE) to replace the existing endcap calorimeters. The CE is a sampling calorimeter with unprecedented transverse and longitudinal readout for both electromagnetic (CE-E) and hadronic (CE-H) compartments. The calorimeter will be built with $\sim$30,000 hexagonal silicon modules. Prototype modules have been constructed with 6-inch hexagonal silicon sensors with cell areas of 1.1~$cm^2$, and the SKIROC2-CMS readout ASIC. Beam tests of different sampling configurations were conducted with the prototype modules at DESY and CERN in 2017 and 2018. This paper describes the construction and commissioning of the CE calorimeter prototype, the silicon modules used in the construction, their basic performance, and the methods used for their calibration., Comment: 35 pages, submitted to JINST

Published
2020

8. The DAQ system of the 12,000 Channel CMS High Granularity Calorimeter Prototype

Author

Acar, B., Adamov, G., Adloff, C., Afanasiev, S., Akchurin, N., Akgün, B., Alhusseini, M., Alison, J., Altopp, G., Alyari, M., An, S., Anagul, S., Andreev, I., Andrews, M., Aspell, P., Atakisi, I. A., Bach, O., Baden, A., Bakas, G., Bakshi, A., Bargassa, P., Barney, D., Becheva, E., Behera, P., Belloni, A., Bergauer, T., Besancon, M., Bhattacharya, S., Bhowmik, D., Bloch, P., Bodek, A., Bonanomi, M., Bonnemaison, A., Bonomally, S., Borg, J., Bouyjou, F., Braga, D., Brashear, J., Brondolin, E., Bryant, P., Bueghly, J., Bilki, B., Burkle, B., Butler-Nalin, A., Callier, S., Calvet, D., Cao, X., Caraway, B., Caregari, S., Ceard, L., Cekmecelioglu, Y. C., Cerminara, G., Charitonidis, N., Chatterjee, R., Chen, Y. M., Chen, Z., Cheng, K. y., Chernichenko, S., Cheung, H., Chien, C. H., Choudhury, S., Čoko, D., Collura, G., Couderc, F., Dumanoglu, I., Dannheim, D., Dauncey, P., David, A., Davies, G., Day, E., DeBarbaro, P., De Guio, F., de La Taille, C., De Silva, M., Debbins, P., Delagnes, E., Deltoro, J. M., Derylo, G., de Almeida, P. G. Dias, Diaz, D., Dinaucourt, P., Dittmann, J., Dragicevic, M., Dugad, S., Dutta, V., Dutta, S., Eckdahl, J., Edberg, T. K., Berni, M. El, Eno, S. C., Ershov, Yu., Everaerts, P., Extier, S., Fahim, F., Fallon, C., Alves, B. A. Fontana Santos, Frahm, E., Franzoni, G., Freeman, J., French, T., Guler, E. Gurpinar, Guler, Y., Gagnan, M., Gandhi, P., Ganjour, S., Garcia-Bellido, A., Gecse, Z., Geerebaert, Y., Gerwig, H., Gevin, O., Gilbert, W., Gilbert, A., Gill, K., Gingu, C., Gninenko, S., Golunov, A., Golutvin, I., Gonzalez, T., Gorbounov, N., Gouskos, L., Gu, Y., Guilloux, F., Gülmez, E., Hammer, M., Harilal, A., Hatakeyama, K., Heering, A., Hegde, V., Heintz, U., Hinger, V., Hinton, N., Hirschauer, J., Hoff, J., Hou, W. S., Isik, C., Incandela, J., Jain, S., Jheng, H. R., Joshi, U., Kara, O., Kachanov, V., Kalinin, A., Kameshwar, R., Kaminskiy, A., Karneyeu, A., Kaya, O., Kaya, M., Khukhunaishvili, A., Kim, S., Koetz, K., Kolberg, T., Kristić, A., Krohn, M., Krüger, K., Kulagin, N., Kulis, S., Kunori, S., Kuo, C. M., Kuryatkov, V., Kyre, S., Köseyan, O. K., Lai, Y., Lamichhane, K., Landsberg, G., Langford, J., Lee, M. Y., Levin, A., Li, A., Li, B., Li, J. -H., Liao, H., Lincoln, D., Linssen, L., Lipton, R., Liu, Y., Lobanov, A., Lu, R. S., Lysova, I., Magnan, A. M., Magniette, F., Maier, A. A., Malakhov, A., Mandjavize, I., Mannelli, M., Mans, J., Marchioro, A., Martelli, A., Masterson, P., Meng, B., Mengke, T., Mestvirishvili, A., Mirza, I., Moccia, S., Morrissey, I., Mudholkar, T., Musić, J., Musienko, I., Nabili, S., Nagar, A., Nikitenko, A., Noonan, D., Noy, M., Nurdan, K., Ochando, C., Odegard, B., Odell, N., Onel, Y., Ortez, W., Ozegović, J., Rodriguez, L. Pacheco, Paganis, E., Pagenkopf, D., Palladino, V., Pandey, S., Pantaleo, F., Papageorgakis, C., Papakrivopoulos, I., Parshook, J., Pastika, N., Paulini, M., Paulitsch, P., Peltola, T., Gomes, R. Pereira, Perkins, H., Petiot, P., Pitters, F., Prosper, H., Prvan, M., Puljak, I., Quast, T., Quinn, R., Quinnan, M., Rapacz, K., Raux, L., Reichenbach, G., Reinecke, M., Revering, M., Rodriguez, A., Romanteau, T., Rose, A., Rovere, M., Roy, A., Rubinov, P., Rusack, R., Simsek, A. E., Sozbilir, U., Sahin, O. M., Sanchez, A., Saradhy, R., Sarkar, T., Sarkisla, M. A., Sauvan, J. B., Schmidt, I., Schmitt, M., Scott, E., Seez, C., Sefkow, F., Sharma, S., Shein, I., Shenai, A., Shukla, R., Sicking, E., Sieberer, P., Sirois, Y., Smirnov, V., Spencer, E., Steen, A., Strait, J., Strebler, T., Strobbe, N., Su, J. W., Sukhov, E., Sun, L., Sun, M., Syal, C., Tali, B., Tok, U. G., Topaksu, A. Kayis, Tan, C. L., Tastan, I., Tatli, T., Thaus, R., Tekten, S., Thienpont, D., Pierre-Emile, T., Tiras, E., Titov, M., Tlisov, D., Troska, J., Tsamalaidze, Z., Tsipolitis, G., Tsirou, A., Tyurin, N., Undleeb, S., Urbanski, D., Ustinov, V., Uzunian, A., van de Klundert, M., Varela, J., Velasco, M., Pinto, M. Vicente Barreto, da Silva, P. M., Virdee, T., de Oliveira, R. Vizinho, Voelker, J., Voirin, E., Wang, Z., Wang, X., Wang, F., Wayne, M., Webb, S. N., Weinberg, M., Whitbeck, A., White, D., Wickwire, R., Wilson, J. S., Wu, H. Y., Wu, L., Yeh, C. H, Yohay, R., Yu, G. B., Yu, S. S., Yu, D., Yumiceva, F., Zacharopoulou, A., Zamiatin, N., Zarubin, A., Zenz, S., Zhang, H., and Zhang, J.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The CMS experiment at the CERN LHC will be upgraded to accommodate the 5-fold increase in the instantaneous luminosity expected at the High-Luminosity LHC (HL-LHC). Concomitant with this increase will be an increase in the number of interactions in each bunch crossing and a significant increase in the total ionising dose and fluence. One part of this upgrade is the replacement of the current endcap calorimeters with a high granularity sampling calorimeter equipped with silicon sensors, designed to manage the high collision rates. As part of the development of this calorimeter, a series of beam tests have been conducted with different sampling configurations using prototype segmented silicon detectors. In the most recent of these tests, conducted in late 2018 at the CERN SPS, the performance of a prototype calorimeter equipped with ${\approx}12,000\rm{~channels}$ of silicon sensors was studied with beams of high-energy electrons, pions and muons. This paper describes the custom-built scalable data acquisition system that was built with readily available FPGA mezzanines and low-cost Raspberry PI computers.

Published
2020
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9. Probing the nature of the conjectured low-spin wobbling bands in atomic nuclei

Author

Guo, S., Zhou, X. H., Petrache, C. M., Lawrie, E. A., Mthembu, S., Fang, Y. D., Wu, H. Y., Wang, H. L., Meng, H. Y., Li, G. S., Qiang, Y. H., Wang, J. G., Liu, M. L., Zheng, Y., Ding, B., Zhang, W. Q., Rohilla, A., Mukhi, K. R., Yang, Y. Y., Ong, H. J., Ma, J. B., Xu, S. W., Bai, Z., Fan, H. L., Huang, J. F., Li, J. H., Xu, J. H., Lv, B. F., Hua, W., Gan, Z. G., and Zhang, Y. H.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

Precession is a unique motion in which the orientation of the rotational axis of a rotating body is not fixed but moving, and it generally exists in the Universe from giant stars through tiny atomic nuclei. In principle, the precession of an atomic nuclide can be approximately described as wobbling motion, arising from the coupling of a rotation and a harmonic vibration. Recently, a number of wobbling bands were reported at low spin, which violate the wobbling approximation that can be valid only at high spin. Here we explore the nature of the reported low-spin wobbling bands. Via a new experiment, we demonstrate that one such band in $^{187}$Au is generated by dominant single-particle excitation rather than by the excitation of a wobbling phonon. We point out that the imperfect research paradigm used previously would lead to unreliable identification of low-spin wobbling bands. Consequently, new experimental approaches should be developed to distinguish among the different excitation mechanisms that can give rise to the observed low-spin bands in odd-even nuclei.

Published
2020
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12. Optical transceivers for event triggers in the ATLAS phase-I upgrade

Author

Zhang, L., Chen, C., Cohen, I., Cruda, E., Gong, D., Hou, S., Hu, X., Huang, X., Li, J. -H., Liu, C., Liu, T., Murphy, L., Schwarz, T., Sun, H., Sun, X., Thomas, J., Wang, Z., Ye, J., and Zhang, W.

Subjects
Physics - Instrumentation and Detectors
Abstract

The ATLAS phase-I upgrade aims to enhance event trigger performance in the Liquid Argon (LAr) calorimeter and the forward muon spectrometer. The trigger signals are transmitted by optical transceivers at 5.12 Gbps per channel in a radiation field. We report the design, quality control in production and ageing test of the transceivers fabricated with the LOCld laser driver and multi-mode 850 nm vertical-cavity surface-emitting laser (VCSEL). The modules are packaged in miniature formats of dual-channel transmitter (MTx) and transceiver (MTRx) for the LAr. The transmitters are also packaged in small form-factor pluggable (SFP) for the muon spectrometer. In production, the LOCld chips and VCSELs in TOSA package were examined before assembly. All of the modules were tested and selected during production for quality control based on the eye-diagram parameters measured at 5.12 Gbps. The yield is 98 % for both the MTx and MTRx on a total 4.7k modules. The uniformity of transmitter channels of a MTx was assured by choosing the TOSA components with approximately equal light powers. The ageing effect is monitored in burn-in of a small batch of transmitter modules with bit-error test and eye-diagrams measured periodically. The observables are stable with the light power degradation within 5 % over a period of more than 6k hours., Comment: 6 pages, 10 figures

Published
2020
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13. Acoustic plasmons and conducting carriers in hole-doped cuprate superconductors

Author

Singh, A., Huang, H. Y., Lane, Christopher, Li, J. H., Okamoto, J., Komiya, S., Markiewicz, Robert S., Bansil, Arun, Fujimori, A., Chen, C. T., and Huang, D. J.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The superconductivity of cuprates, which has been a mystery ever since its discovery decades ago, is created through doping electrons or holes into a Mott insulator. There, however, exists an inherent electron-hole asymmetry in cuprates. The layered crystal structures of cuprates enable collective charge excitations fundamentally different from those of three-dimensional metals, i.e., acoustic plasmons. Acoustic plasmons have been recently observed in electron-doped cuprates by resonant inelastic X-ray scattering (RIXS); in contrast, there is no evidence for acoustic plasmons in hole-doped cuprates, despite extensive measurements. This contrast led us to investigate whether the doped holes in cuprates La$_{2-x}$Sr$_x$CuO$_4$ are conducting carriers or are too incoherent to induce collective charge excitation. Here we present momentum-resolved RIXS measurements and calculations of collective charge response via the loss function to reconcile the aforementioned issues. Our results provide unprecedented spectroscopic evidence for the acoustic plasmons and long sought conducting p holes in hole-doped cuprates.

Published
2020
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14. Development of the Soft X-ray AGM-AGS RIXS Beamline at Taiwan Photon Source

Author

Singh, A., Huang, H. Y., Chu, Y. Y., Hua, C. Y., Lin, S. W., Fung, H. S., Shiu, H. W., Chang, J., Li, J. H., Okamoto, J., Chiu, C. C., Chang, C. H., Wu, W. B., Perng, S. Y., Chung, S. C., Kao, K. Y., Yeh, S. C., Chao, H. Y., Chen, J. H., Huang, D. J., and Chen, C. T.

Subjects
Physics - Instrumentation and Detectors, Condensed Matter - Strongly Correlated Electrons
Abstract

We report on the development of a high-resolution and highly efficient beamline for soft-X-ray resonant inelastic X-ray scattering (RIXS) located at Taiwan Photon Source. This beamline adopts an optical design that uses an active grating monochromator (AGM) and an active grating spectrometer (AGS) to implement the energy compensation principle of grating dispersion. Active gratings are utilized to diminish defocus, coma and higher-order aberrations as well as to decrease the slope errors caused by thermal deformation and optical polishing. The AGS is mounted on a rotatable granite platform to enable momentum-resolved RIXS measurements with scattering angle over a wide range. Several high-precision instruments developed in house for this beamline are briefly described. The best energy resolution obtained from this AGM-AGS beamline was 12.4 meV at 530 eV, achieving a resolving power 42,000, while the bandwidth of the incident soft X-rays was kept at 0.5 eV. To demonstrate the scientific impacts of high-resolution RIXS, we present an example of momentum-resolved RIXS measurements on a high-temperature superconducting cuprate, La$_{2-x}$Sr$_x$CuO$_4$. The measurements reveal the A$_{1g}$ apical oxygen phonons in superconducting cuprates, opening a new opportunity to investigate the coupling between these phonons and charge density waves., Comment: 9 pages, p figures, submitted to J. of Synchrotron Radiation. Revise expression

Published
2020
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16. Persistent gapless surface states in MnBi2Te4/Bi2Te3 superlattice antiferromagnetic topological insulator

Author

Xu, L. X., Mao, Y. H., Wang, H. Y., Li, J. H., Chen, Y. J., Xia, Y. Y. Y., Li, Y. W., Zhang, J., Zheng, H. J., Huang, K., Zhang, C. F., Cui, S. T., Liang, A. J., Xia, W., Su, H., Jung, S. W., Cacho, C., Wang, M. X., Li, G., Xu, Y., Guo, Y. F., Yang, L. X., Liu, Z. K., and Chen, Y. L.

Subjects
Condensed Matter - Materials Science
Abstract

Magnetic topological quantum materials (TQMs) provide a fertile ground for the emergence of fascinating topological magneto-electric effects. Recently, the discovery of intrinsic antiferromagnetic (AFM) topological insulator MnBi2Te4 that could realize quantized anomalous Hall effect and axion insulator phase ignited intensive study on this family of TQM compounds. Here, we investigated the AFM compound MnBi4Te7 where Bi2Te3 and MnBi2Te4 layers alternate to form a superlattice. Using spatial- and angle-resolved photoemission spectroscopy, we identified ubiquitous (albeit termination dependent) topological electronic structures from both Bi2Te3 and MnBi2Te4 terminations. Unexpectedly, while the bulk bands show strong temperature dependence correlated with the AFM transition, the topological surface states show little temperature dependence and remain gapless across the AFM transition. The detailed electronic structure of MnBi4Te7 and its temperature evolution, together with the results of its sister compound MnBi2Te4, will not only help understand the exotic properties of this family of magnetic TQMs, but also guide the design for possible applications., Comment: 22 pages, 4 figures

Published
2019
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17. Topological Electronic Structure and Its Temperature Evolution in Antiferromagnetic Topological Insulator MnBi2Te4

Author

Chen, Y. J., Xu, L. X., Li, J. H., Li, Y. W., Zhang, C. F., Li, H., Wu, Y., Liang, A. J., Chen, C., Jung, S. W., Cacho, C., Wang, H. Y., Mao, Y. H., Liu, S., Wang, M. X., Guo, Y. F., Xu, Y., Liu, Z. K., Yang, L. X., and Chen, Y. L.

Subjects
Condensed Matter - Materials Science
Abstract

Topological quantum materials coupled with magnetism can provide a platform for realizing rich exotic physical phenomena, including quantum anomalous Hall effect, axion electrodynamics and Majorana fermions. However, these unusual effects typically require extreme experimental conditions such as ultralow temperature or sophisticate material growth and fabrication. Recently, new intrinsic magnetic topological insulators were proposed in MnBi2Te4-family compounds - on which rich topological effects could be realized under much relaxed experimental conditions. However, despite the exciting progresses, the detailed electronic structures observed in this family of compounds remain controversial up to date. Here, combining the use of synchrotron and laser light sources, we carried out comprehensive and high resolution angle-resolved photoemission spectroscopy studies on MnBi2Te4, and clearly identified its topological electronic structures including the characteristic gapless topological surface states. In addition, the temperature evolution of the energy bands clearly reveals their interplay with the magnetic phase transition by showing interesting differences for the bulk and surface states, respectively. The identification of the detailed electronic structures of MnBi2Te4 will not only help understand its exotic properties, but also pave the way for the design and realization of novel phenomena and applications., Comment: 18 pages, 4 figure

Published
2019
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26. Property Analysis of Laser Welded Dissimilar Q345D/20Mn2 Steel Joints.

Author

Li, X. X., Li, J. H., Yao, F. P., and Meng, Y. Y.

Subjects
*LASER welding, *DISSIMILAR welding, *STEEL welding, *STEEL, *WELDING, *POWDERS
Abstract

A fibre laser was used to weld Q345D/20Mn2 dissimilar steel with and without a Ni60 powder filler. Finite element (FE) simulation of the temperature and stress fields in the laser beam welding (LBW) was conducted COMSOL. Experimental investigation determined the effect of Ni-based powder filled welding on the microstructure, morphology, element content, microhardness and fracture morphology of the weld cross-section. The results show that when the laser power was 2700 W, the scanning speed was 1 mm/s and the out-of-focus amount was 0 mm, the tensile properties of Q345D/20Mn2 steel welds were optimal and deformation was minimal. Under such conditions the depth of the weld pool can reach 2.7 mm and the width 2.8 mm. After the Ni-based powder melts and penetrates the bottom of the base material (BM) along the weld seam, small cytosolic, equiaxed and columnar crystal grains can be observed near the fusion line, and the Ni-based filler powder can achieve a good metallurgical bond with the BM. The location of tensile fracture is at the weld and small tough nests can be observed in the cross-section leading to judgment that the fracture mode is ductile. [ABSTRACT FROM AUTHOR]

Published
2024

27. Achieving Maximum Performance of a Laser Clad Ni-based Coating Through Optimization of Laser Remelting Processing Parameters.

Author

YANG, Y. H., LI, J. H., YAO, F. P., and ZHENG, F. Y.

Subjects
*LASERS, *SURFACE coatings, *RESIDUAL stresses
Abstract

Through simulation based on the Workbench platform in ANSYS the optimal laser remelting process parameters were identified to achieve the maximum performance of a Ni60 coating laser clad onto a H13 steel surface. Laser remelting with a fibre laser was conducted according to the optimal process parameters obtained and the coating morphology, microstructure and microhardness after remelting were analysed. The results show that when the laser power was 1200 W and the scanning speed was 4 mm/s the remelted coating has the smallest residual stress value, pores in the coating were basically eliminated, the organization was dense, the hardness improved and the coating quality was the best. When the laser power was 900 W and the scanning speed was 2 mm/s the maximum residual stress value of the remelted coating was slightly smaller than that of the un-remelted coating, the coating morphology quality was better, and there were very few bubbles. [ABSTRACT FROM AUTHOR]

Published
2024

28. Optimizing the Microstructure and Mechanical Properties of a Laser Clad Ti-6Al-4V Coating by Laser Shock Peening (LSP).

Author

REN, W.-B., FANG, S.-Y., LI, J.-H., YU, W.-C., and WANG, Y.-J.

Subjects
MICROSTRUCTURE, RESIDUAL stresses, MATERIAL plasticity, LASERS, LASER peening, SURFACE coatings
Abstract

In view of the difficulties such as coarse microstructure, performance degradation and excessive residual stress during the preparation of Ti-6Al-4V layers by laser cladding, the microstructure and mechanical properties of such a Ti-6Al-4V coating were optimized and improved based on the plastic deformation effect caused by laser shock peening (LSP). The characteristics of phase composition, changes in microstructure and morphology, grain plastic deformation and the influence of mechanical properties of the laser clad Ti-6Al-4V coating were studied pre- and post-LSP. The results indicate that the α/α' phase content increases and the β phase content decreases after LSP. The β phase and acicular martensite α' phase is refined significantly and divided, and the basket structure presents a more dense and staggered distribution after LSP. Laser cladding causes the grains in the Ti-6Al-4V coating to undergo plastic strain and the degree of grain refinement was significantly improved following LSP. The microhardness at the top of the laser clad Ti-6Al-4V coating increases from 23 to 30% compared after LSP. At the same time, the LSP promotes the transformation of residual tensile stress to compressive stress on the surface of the laser clad Ti-6Al-4V coating, with an average residual compressive stress value of about 339 MPa. This study provides theoretical and methodological references for optimizing the microstructure and properties of Ti-6Al-4V coatings. [ABSTRACT FROM AUTHOR]

Published
2024

37. Propagating Wave Patterns in a Derivative Nonlinear Schr\'odinger System with Quintic Nonlinearity

Author

Rogers, C., Malomed, B. A., Li, J. H., and Chow, K. W.

Subjects
Nonlinear Sciences - Pattern Formation and Solitons
Abstract

Exact expressions are obtained for a diversity of propagating patterns for a derivative nonlinear Schr\"odinger equation with a quintic nonlinearity. These patterns include bright pulses, fronts and dark solitons. The evolution of the wave envelope is determined via a pair of integrals of motion, and reduction is achieved to Jacobi elliptic cn and dn function representations. Numerical simulations are performed to establish the existence of parameter ranges for stability. The derivative quintic nonlinear Schr\"odinger model equations investigated here are important in the analysis of strong optical signals propagating in spatial or temporal waveguides., Comment: J. Phys. Soc. Jpn. in press

Published
2012

38. Modulation Instabilities in Birefringent Two-Core Optical Fibers

Author

Li, J. H., Chiang, K. S., Malomed, B. A., and Chow, K. W.

Subjects
Physics - Optics, Nonlinear Sciences - Pattern Formation and Solitons
Abstract

Previous studies of the modulation instability (MI) of continuous waves (CWs) in a two-core fiber (TCF) did not consider effects caused by co-propagation of the two polarized modes in a TCF that possesses birefringence, such as cross-phase modulation (XPM), polarization-mode dispersion (PMD), and polarization-dependent coupling (PDC) between the cores. This paper reports an analysis of these effects on the MI by considering a linear-birefringence TCF and a circular-birefringence TCF, which feature different XPM coefficients. The analysis focuses on the MI of the asymmetric CW states in the TCFs, which have no counterparts in single-core fibers. We find that, the asymmetric CW state exists when its total power exceeds a threshold (minimum) value, which is sensitive to the value of the XPM coefficient. We consider, in particular, a class of asymmetric CW states that admit analytical solutions. In the anomalous dispersion regime, without taking the PMD and PDC into account, the MI gain spectra of the birefringent TCF, if scaled by the threshold power, are almost identical to those of the zero-birefringence TCF. However, in the normal dispersion regime, the power-scaled MI gain spectra of the birefringent TCFs are distinctly different from their zero-birefringence counterparts, and the difference is particularly significant for the circular-birefringence TCF, which takes a larger XPM coefficient. On the other hand, the PMD and PDC only exert weak effects on the MI gain spectra. We also simulate the nonlinear evolution of the MI of the CW inputs in the TCFs and obtain a good agreement with the analytical solutions., Comment: J. Physics B:At. Mol. Opt. Phys., in press

Published
2012

39. Effect of Strain on the Growth of InAs/GaSb Superlattices: An X-Ray Study

Author

Li, J. H., Stokes, D. W., Wickett, J. C., Caha, O., Bassler, K. E., and Moss, S. C.

Subjects
Condensed Matter - Materials Science
Abstract

We present a detailed x-ray diffraction study of the strain in InAs/GaSb superlattices grown by molecular beam epitaxy. The superlattices were grown with either InSb or GaAs interfaces. We show that the superlattice morphology, either planar or nanostructured, is dependent on the chemical bonds at the heterointerfaces. In both cases, the misfit strain has been determined for the superlattice layers and the interfaces. We also determined how the magnitude and sign of this strain is crucial in governing the morphology of the superlattice. Our analysis suggests that the growth of self-assembled nanostructures may be extended to many systems generally thought to have too small a lattice mismatch., Comment: 40 pages, 14 figures, 2 tables. Submitted to Journal of Applied Physics in November 2009

Published
2009
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40. Electromagnetic Landau Resonance: MMS Observations.

Author

Liu, Z.‐Y., Zong, Q.‐G., Wang, Y.‐F., Zhou, X.‐Z., Wang, S., and Li, J.‐H.

Subjects
ELECTROMAGNETIC waves, ELECTROSTATIC fields, ELECTROMAGNETIC interactions, ELECTROMAGNETIC fields, SPACE plasmas, ELECTROMAGNETIC pulses, RESONANCE
Abstract

Theoretical analysis has revealed a specific resonance that shares the same condition as Landau resonance, but instead involves wave electromagnetic fields rather than traditionally electrostatic fields. While this resonance, referred to as electromagnetic Landau resonance due to its properties, is considered significant for magnetospheric dynamics, rare reports or evaluations based on observations have been made thus far. Here, we present an event detected by the Magnetospheric Multiscale mission near the dayside magnetopause. During this event, ∼748‐eV protons are observed to be in resonance with a wave. Detailed data analysis demonstrates the resonant velocity closely matches the wave's parallel phase speed, which, combined with the significant work done by wave perpendicular electric field, confirms this interaction as electromagnetic Landau resonance. Further investigation indicates these protons are being secularly accelerated within this resonance. Consequently, our observations provide the first empirical evidence supporting the previously suggested theoretical importance of the electromagnetic Landau resonance. Plain Language Summary: The electromagnetic Landau resonance shares the same resonance condition as the normal Landau resonance, but differs in that it involves the electromagnetic components of wave fields instead of the electrostatic components found in the case of the latter. Although it has been examined in theories and confirmed to occur in space plasmas experimentally, this resonance, especially the accompanying evolution of particle velocity distributions, has yet to be evaluated quantitatively through spacecraft observations. In this paper, we report the first observation of this resonance obtained by the Magnetospheric Multiscale mission near the dayside magnetosphere. In the reported case, protons of ∼400–1,000 eV are found to be in resonance with a wave. A more detailed examination of the observed fields and protons shows the corresponding resonant velocity is nearly identical to the wave's parallel phase speed. This observation, combined with the significant work done by wave perpendicular electric field, conclusively confirms the observed interaction as the electromagnetic Landau resonance. Further investigation indicates the protons are secularly accelerated by the wave via this resonance. Hence, our observations provide empirical evidence supporting the previously suggested theoretical significance of the electromagnetic Landau resonance. Key Points: MMS observations of electromagnetic Landau resonance near the dayside magnetopause are presentedThis resonance follows the same condition as the Landau resonance, but modulates particles via the electromagnetic components of wave fieldsAnalysis of the observed fields and protons provide conclusive evidence for this resonance accelerating protons [ABSTRACT FROM AUTHOR]

Published
2024
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41. Role of alanine aminotransferase in the effects of urinary caffeine concentration and its primary metabolite concentration on cognitive function in older adults: Bayesian Kernel Machine regression analysis and mediation analysis.

Author

QIN, Y.-J., WANG, Z.-G., GONG, J.-H., GONG, J.-P., and LI, J.-H.

Abstract

OBJECTIVE: This study aimed to explore the role of alanine aminotransferase (ALT) in the effects of urinary caffeine and its primary metabolites on cognitive function in elderly people. MATERIALS AND METHODS: In this investigation, we meticulously curated a cohort from the 2011-2014 National Health and Nutrition Examination Survey (NHANES) database. Animal fluency emerged as the pivotal metric for assessing cognitive function within our study population. In order to navigate the intricacies of mixture analysis and circumvent potential complexities, we harnessed the power of Bayesian kernel machine regression (BKMR) models. This method allowed us to dissect the nuanced impacts of caffeine and its primary urinary metabolites on cognitive function. While accounting for caffeine and its metabolites, we analyzed the relationship between ALT and cognitive function through non-linear dynamics. Lastly, employing structural equation modeling, we probed the intriguing question of whether ALT mediates the influence of 3,7-dimethylxanthine on cognitive function. This comprehensive approach has unveiled a deeper understanding of the multifaceted interplay among these variables, offering invaluable insights into the determinants of cognitive function within our cohort. RESULTS: After meticulous adjustment for various covariates, our linear regression analysis unveiled a noteworthy finding: 3,7-dimethylxanthine demonstrated a significant positive correlation with cognitive function (p < 0.05). Importantly, within the BKMR model employed, 3,7-dimethylxanthine emerged as the most influential factor within the compound, with posterior inclusion probabilities of 0.995 and 0.939. Furthermore, our single-exposure effect model confirmed its presence at the 25th, 510th, and 75th percentile concentrations of other components within the compound. Interestingly, bivariate concentration curves indicated no interaction within the compound, underscoring the prominent impact of 3,7-dimethylxanthine on cognitive function. Subsequently, through a test of Restricted Cubic Splines (RCS), we revealed a non-linear relationship between ALT and cognitive function at the 10th, 50th, and 90th percentiles (p < 0.05), indicating a heightened risk of diminished cognitive function in the low ALT group. Employing structural equation modeling, we meticulously examined the mediating role of ALT in relation to 3,7-dimethylxanthine and cognitive function. However, our study results did not yield significant evidence of a mediating effect. This comprehensive analysis elucidates the intricate interplay between these variables, unveiling the subtle mechanisms governing cognitive function. CONCLUSIONS: In this study, a noteworthy positive correlation was observed between 3,7-dimethylxanthine and cognitive function. Additionally, a non-linear relationship was identified between ALT and cognitive function, with lower levels of ALT associated with a decline in cognitive function. The RCS trend suggested that higher levels of ALT may similarly lead to diminished cognitive performance. However, in our pursuit to ascertain potential mediation, we regrettably found no significant evidence supporting mediation among these factors involving ALT. This underscores the need for more comprehensive investigations and expanded clinical explorations into the intricate associations among these three pivotal elements. [ABSTRACT FROM AUTHOR]

Published
2024

42. Robustness and stability of doubly periodic patterns of the focusing nonlinear Schrödinger equation.

Author

Yin, H. M., Li, J. H., Zheng, Z., Chiang, K. S., and Chow, K. W.

Abstract

The nonlinear Schrödinger equation possesses doubly periodic solutions expressible in terms of the Jacobi elliptic functions. Such solutions can be realized through doubly periodic patterns observed in experiments in fluid mechanics and optics. Stability and robustness of these doubly periodic wave profiles in the focusing regime are studied computationally by using two approaches. First, linear stability is considered by Floquet theory. Growth will occur if the eigenvalues of the monodromy matrix are of a modulus larger than unity. This is verified by numerical simulations with input patterns of different periods. Initial patterns associated with larger eigenvalues will disintegrate faster due to instability. Second, formation of these doubly periodic patterns from a tranquil background is scrutinized. Doubly periodic profiles are generated by perturbing a continuous wave with one Fourier mode, with or without the additional presence of random noise. Effects of varying phase difference, perturbation amplitude, and randomness are studied. Varying the phase angle has a dramatic influence. Periodic patterns will only emerge if the perturbation amplitude is not too weak. The growth of higher-order harmonics, as well as the formation of breathers and repeating patterns, serve as a manifestation of the classical problem of Fermi–Pasta–Ulam–Tsingou recurrence. [ABSTRACT FROM AUTHOR]

Published
2024
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