From Heisenberg matrix mechanics to EBK quantization: theory and first applications

Despite the seminal connection between classical multiply-periodic motion and Heisenberg matrix mechanics and the massive amount of work done on the associated problem of semiclassical (EBK) quantization of bound states, we show that there are, nevertheless, a number of previously unexploited aspects of this relationship that bear on the quantum-classical correspondence. In particular, we emphasize a quantum variational principle that implies the classical variational principle for invariant tori. We also expose the more indirect connection between commutation relations and quantization of action variables. With the help of several standard models with one or two degrees of freedom, we then illustrate how the methods of Heisenberg matrix mechanics described in this paper may be used to obtain quantum solutions with a modest increase in effort compared to semiclassical calculations. We also describe and apply a method for obtaining leading quantum corrections to EBK results. Finally, we suggest several new or modified applications of EBK quantization.Comment: 37 pages including 3 poscript figures, submitted to Phys. Rev.

Electron trapping in freely expanding ultracold neutral plasmas

We report on the self-induced electron trapping occurring in a ultracold neutral plasma that is set to expand freely. At the early stages of the plasma, the ions are not thermalized follow a Gaussian spatial profile, providing the trapping to the coldest electrons. In the present work, we provide a theoretical model describing the electrostatic potential and perform molecular dynamics simulations to validate our findings. We show that in the strong confinement regime, the plasma potential is of a Thomas-Fermi type, similar to the case of heavy atomic species. The numerically simulated spatial profiles of the particles corroborate this claim. We also extract the electron temperature and coupling parameter from the simulation, so the duration of the transient Thomas-Fermi is obtained

Inscribing a discipline: tensions in the field of bioinformatics

Bioinformatics, the application of computer science to biological problems, is a central feature of post-genomic science which grew rapidly during the 1990s and 2000s. Post-genomic science is often high-throughput, involving the mass production of inscriptions [Latour and Woolgar (1986), Laboratory Life: the Construction of Scientific Facts. Princeton, NJ: Princeton University Press]. In order to render these mass inscriptions comprehensible, bioinformatic techniques are employed, with bioinformaticians producing what we call secondary inscriptions. However, despite bioinformaticians being highly skilled and credentialed scientists, the field struggles to develop disciplinary coherence. This paper describes two tensions militating against disciplinary coherence. The first arises from the fact that bioinformaticians as producers of secondary inscriptions are often institutionally dependent, subordinate even, to biologists. With bioinformatics positioned as service, it cannot determine its own boundaries but has them imposed from the outside. The second tension is a result of the interdisciplinary origin of bioinformatics – computer science and biology are disciplines with very different cultures, values and products. The paper uses interview data from two different UK projects to describe and examine these tensions by commenting on Calvert's [(2010) “Systems Biology, Interdisciplinarity and Disciplinary Identity.” In Collaboration in the New Life Sciences, edited by J. N. Parker, N. Vermeulen and B. Penders, 201–219. Farnham: Ashgate] notion of individual and collaborative interdisciplinarity and McNally's [(2008) “Sociomics: CESAGen Multidisciplinary Workshop on the Transformation of Knowledge Production in the Biosciences, and its Consequences.” Proteomics 8: 222–224] distinction between “black box optimists” and “black box pessimists.

Multimode collective scattering of light in free space by a cold atomic gas

We have studied collective recoil lasing by a cold atomic gas, scattering photons from an incident laser into many radiation modes in free space. The model consists of a system of classical equations for the atomic motion of N atoms where the radiation field has been adiabatically eliminated. We performed numerical simulations using a molecular dynamics code pepc (Pretty Efficient Parallel Coulomb Solver) to track the trajectories of the atoms. These simulations show the formation of an atomic density grating and collective enhancement of scattered light, both of which are sensitive to the shape and orientation of the atomic cloud. In the case of an initially circular cloud, the dynamical evolution of the cloud shape plays an important role in the development of the density grating and collective scattering. The ability to use efficient molecular dynamics codes will be a useful tool for the study of the multimode interaction between light and cold gases

Interventions to increase engagement with rehabilitation in adults with acquired brain injury: A systematic review

Rehabilitation in adults with acquired brain injury is often hampered by a lack of client engagement with the rehabilitation process, leading to frustration, withdrawal of services and poorer recovery. Motivation, apathy and awareness are potential mechanisms underlying engagement, but few studies have suggested potential intervention techniques. A systematic review of the literature was carried out to identify and evaluate interventions designed to increase rehabilitation engagement in adults with acquired brain injury. Database searches used the following terms: rehabilitation, brain injury, and compliance/engagement/adherence in PsychInfo, Medline, Cinahl, Embase, AMED, Web of Knowledge, PsycBite, Cochrane clinical trials, and clinicaltrials.org. Hand searches were conducted of reference lists and relevant journals. Fifteen studies were included in the review. Intervention techniques fell into two broad categories: behavioural modification techniques and cognitive/meta-cognitive skills. Contingent reward techniques were most effective at increasing adherence and compliance, while interventions enabling clients' active participation in rehabilitation appeared to increase engagement and motivation. The review highlighted methodological and measurement inconsistencies in the field and suggested that interventions should be tailored to clients' abilities and circumstances

Recent progress of JT-60SA project toward plasma operation

Superconducting (SC) tokamak JT-60SA plays an essential role in fusion research and development by supporting and complementing the ITER project, providing directions to the DEMO design activity and fostering next generation scientists and engineers. Since the short circuit incident at the terminal joints of equilibrium field coil #1 during the integrated commissioning (IC) in March 2021, both EU and JA implementing agencies (IAs) have examined how to ensure safe operation of JT-60SA by mitigating the risk of possible discharge occurrence inside the cryostat. Based on the experience of the global Paschen tests, the IAs have established a strategy of risk mitigation measures, which is a combination of (i) reinforcement of insulation, (ii) avoiding unnecessary voltage application to the coil systems and (iii) immediate de-energization of the coils when deteriorated vacuum conditions are detected. Thanks to the considerable efforts of the Integrated Project Team members, the IC restarted in May 2023. After confirmation of the SC state of the coil systems (TF, EF and CS), the coil energization test and the plasma operation phase 1 (OP-1) started. The first plasma was successfully achieved on 23 October 2023 with a limited value of voltage and current applied to the coils. The plasma configuration control was also confirmed with low plasma current and low auxiliary heating power conditions. Based on the IO–F4E–QST collaboration, activities of JT-60SA have been shared with the IO and provided an important lesson for ITER assembly and commissioning, and will provide an outstanding contribution to fusion research at large. After OP-1, maintenance & enhancement phase 1 (M/E-1) starts from January 2024, in which in-vessel components are installed, and heating and diagnostic systems are extensively upgraded to allow a high power heating experiment planned in OP-2. In order to make the best use of JT-60SA, a newly organized JT-60SA experiment team will refine the research plan for the future high heating power operation phase.The authors gratefully acknowledge members of EU-IA, JAIA, Project Team and voluntary contributors for their strenuous efforts to get over a lot of technical difficulties with the JT-60SA Project over the past years. The authors also appreciate the members of the European and Japanese fusion communities who have made great contributions in examination of detailed research targets in the operational phases and patiently waited for the restart of the IC.Article signat per 434 autors/es: H. Shirai, K. Takahashi, E. Di Pietro, D. Abate, W. Abdel Maksoud, H. Abe, N. Aiba, T. Abe, M. Akimitsu, J. Ayllon-Guerola, T. Arai, J.-F. Artaud, N. Asakura, N. Ashikawa, L. Balbinot, P. Barabaschi, O. Baulaigue, E. Belonohy, A. Belpane, W. Bin, F. Bombarda, T. Bolzonella, F. Bonne, M. Bonotto, J. Botija, J. Buermans, S. Cabrera-Pérez, A. Cardella, D. Carralero, L. Carraro, J. Cavalier, M. Cavinato, M. Chernyshova, S. Chiba, S. Clement-Lorenzo, V. Cocilovo, S. Coda, R. Coelho, I. Coffey, B. Collin, V. Corato, A. Cucchiaro, T. Czarski, M. Dairaku, S. Davis, C. Day, E. Dela Luna, G. De Tommasi, P. Decool, L. Di Pace, M. Dibon, G. Disset, F. D'Lsa, A. Ejiri, Y. Endo, N. Ezumi, G. Falchetto, A. Fassina, P. Fejoz, A. Ferro, W. Fietz, L. Figini, T. Fornal, G. Frello, T. Fujita, T. Fukuda, K. Fukui, M. Fukumoto, H. Funaba, M. Furukawa, S. Futatani, L. Gabellieri, E. Gaio, K. Galazka, J. Garcia, J. Garcia-Dominguez, J. Garcia-Lopez, M. Garcia-Munoz, L. Garzotti, F. Gasparini, S. Gharafi, L. Giacomelli, G. Ginoulhiac, G. Giruzzi, L. Giudicotti, J. Gonzalez-Martin, R. Guillén-González, N. Hajnal, S. Hall, K. Hamada, K. Hanada, M. Hanada, K. Hasegawa, S. Hatakeyama, V. Hauer, N. Hayashi, T. Hayashi, R. Heller, J. Hidalgo-Salaverri, S. Higashijima, J. Hinata, S. Hiranai, J. Hiratsuka, R. Hiwatari, C. Hoa, H. Homma, A. Honda, M. Honda, K. Hoshino, H. Hurzlmeier, M. Iafrati, K. Ibano, H. Ichige, M. Ichikawa, M. Ichimura, K. Ida, S. Ide, H. Idei, M. Iguchi, T. Iijima, S. Iio, R. Ikeda, Y. Ikeda, T. Imai, R. Imazawa, S. Inagaki, M. Inomoto, S. Inoue, A. Isayama, S. Ishida, Y. Ishii, M. Isobe, F. Janky, E. Joffrin, A. Jokinen, S. Kado, S. Kajita, K. Kajiwara, Y. Kamada, I. Kamata, A. Kaminaga, K. Kamiya, D. Kanapienyte, Y. Kashiwa, M. Kashiwagi, K. Katayama, Y. Kawamata, G. Kawamura, K. Kawano, Y. Kazakov, K. Kimura, F. Kin, M. Kisaki, S. Kitajima, K. Kiyono, K. Kizu, Y. Ko, K. Kobayashi, M. Kobayashi, S. Kobayashi, Ta. Kobayashi, To. Kobayashi, G. Kocsis, A. Kojima, S. Kokusen, M. Komata, K. Komuro, S. Konishi, A. Kovacsik, I. Ksiazek, M. Kubkowska, G. Kühner, M. Kuramochi, K. Kurihara, T. Kurki-Suonio, A.B. Kurniawan, T. Kuwata, B. Lacroix, V. Lamaison, A. Lampasi, P. Lang, P. Lauber, K. Lawson, Q. LeCoz, A. Louzguiti, R. Maekawa, T. Maekawa, S. Maeyama, G. Maffia, P. Maget, J. Mailloux, I. Maione, A. Maistrello, K. Malinowski, A. Mancini, G. Marchiori, J.-L. Marechal, V. Massaut, S. Masuzaki, R. Matoike, G. Matsunaga, S. Matsunaga, A. Matsuyama, Ch Mayri, M. Mattei, M. Medrano, A. Mele, I. Meyer, F. Michel, T. Minami, Y. Miyata, J. Miyazawa, Y. Miyo, T. Mizuuchi, K. Mogaki, J. Morales, P. Moreau, T. Morisaki, S. Morishima, S. Moriyama, A. Moro, H. Murakami, M. Murayama, S. Murakami, K. Nagasaki, O. Naito, N. Nakamura, S. Nakamura, T. Nakano, Y. Nakashima, V. Nardino, E. Narita, Y. Narushima, K. Natsume, S. Nemoto, R. Neu, S. Nicollet, M. Nishikawa, S. Nishimura, T. Nishitani, M. Nishiura, T. Nishiyama, M. Nocente, Y. Nobuta, L. Novello, F. Nunio, S. Ochoa, K. Ogawa, T. Ogawa, Y. Ogawa, S. Ohdachi, Y. Ohmori, N. Ohno, Y. Ohtani, K. Ohtsu, M. Ohzeki, T. Oishi, J. Okano, K. Okano, Y. Onishi, M. Osakabe, T. Oshima, V. Ostuni, A. Owada, M. Oya, Y. Oya, T. Ozeki, M.M. Parody Guzmán, R. Pasqualotto, S. Pelli, E. Perelli, E. Peretti, G. Phillips, C. Piccinni, L. Pigatto, A. Pironti, A. Pizzuto, B. Plöckl, G. Polli, J.-M. Poncet, P. Ponsot, G. Pucella, M. Puiatti, D. Radloff, V. Raimondi, F. Ramos, P. Rancsik, D. Ricci, S. Ricciarini, N. Richermoz, E. Rincon, A. Romano, P. Rossi, P. Roussel, G. Rubino, H. Saeki, A. Sagara, S. Sakakibara, H. Sakamoto, Miki Sakamoto, Mizu Sakamoto, Y. Sakamoto, A. Sakasai, S. Sakata, R. Sakurai, B. Salanon, A. Salmi, G. Sannazzaro, R. Sano, A. Sanpei, T. Sasajima, S. Sasaki, H. Sasao, F. Sato, M. Sato, T. Sato, M. Sawahata, A. Scherber, S. Scully, J. Segado-Fernandez, M. Seki, N. Seki, S. Seki, Y. Shibama, Y. Shibata, T. Shikama, K. Shimada, M. Shimono, J. Shinde, T. Shinya, K. Shinohara, J. Shiraishi, S. Soare, A. Soleto, Y. Someya, S. Sonoda, C. Sozzi, E. Streciwilk-Kowalska, H. Strobel, M. Sueoka, A. Sukegawa, S. Sumida, H. Suzuki, Ma Suzuki, Mi Suzuki, S. Suzuki, T. Suzuki, Y. Suzuki, J. Svoboda, T. Szabolics, T. Szepesi, Y. Takase, M. Takechi, K. Takeda, Y. Takeiri, H. Takenaga, C. Taliercio, N. Tamura, Hiro Tanaka, Hito Tanaka, K. Tanaka, Y. Tanaka, K. Tani, H. Tanigawa, M. Tardocchi, A. Terakado, M. Terakado, T. Terakado, B. Teuchner, B. Tilia, H. Tobari, H. Tobita, K. Tobita, K. Toi, N. Toida, H. Tojo, M. Tokitani, T. Tokuzawa, V. Tormarchio, M. Tomine, A. Torre, T. Totsuka, K. Tsuchiya, N. Tsujii, D. Tsuru, H. Tsutsui, M. Uchida, Y. Ueda, J. Uno, H. Urano, K. Usui, H. Utoh, M. Valisa, M. Vallar, R. Vallcorba-Carbonel, J.-C. Vallet, J. Varela, J. Vega, M. Verrecchia, L. Vieillard, F. Villone, P. Vincenzi, K. Wada, R. Wada, T. Wakatsuki, M. Wanner, F. Watanabe, K. Watanabe, S. Watanabe, T. Wauters, S. Wiesen, M. Wischmeier, M. Yagi, J. Yagyu, M. Yajima, S. Yamamoto, H. Yamanaka, K. Yamauchi, Y. Yamauchi, H. Yamazaki, K. Yamazaki, R. Yamazaki, S. Yamoto, S. Yanagi, K. Yanagihara, S. Yokooka, M. Yokoyama, T. Yokoyama, M. Yoshida, M. Yoshimura, N. Yoshizawa, K. Yuinawa, L. Zani, P. Zito.Postprint (published version