{"title":"Confinement Experiments of Pure Ion and Electron Plasmas in a Nested Trap","authors":"Toshikazu OKADA, Haruhiko HIMURA, Yutaro NAKAJIMA, Akio SANPEI","doi":"10.1585/pfr.18.2401072","DOIUrl":"https://doi.org/10.1585/pfr.18.2401072","url":null,"abstract":"We perform experiments where lithium ion and electron plasmas are simultaneously confined in a nested trap to detect two-fluid plasma states. However, the behavior of charged particles in the nested trap is unexplained. Results of experiments demonstrate that the number of charged particles in the outer wells of the nested trap rapidly decreases and that peculiar deformations in ion and electron plasmas cause in some conditions.","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135865352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of Energy-Scaling of Thrust Performance for Laser Fusion Rocket","authors":"Taiki INATOMI, Naoji YAMAMOTO, Hideki NAKASHIMA, Yoshitaka MORI, Toshiyuki ISE, Shunsuke MURATA, Kazuhiro YAGI, Taichi MORITA","doi":"10.1585/pfr.18.1404080","DOIUrl":"https://doi.org/10.1585/pfr.18.1404080","url":null,"abstract":"A laser fusion rocket has been proposed for interplanetary flight. This rocket generates a high-energy plasma via laser-fusion and expels it via a magnetic nozzle. The magnetic nozzle is a key component for the rocket performance, and we have investigated the impulse bit generated from the magnetic nozzle by using simulations and experiments in relatively low energy regime of a few joules. In addition, the energy dependence on the thrust performance is an essential factor to evaluate and design the laser fusion rocket. Here, we conducted numerical simulations in energy regimes from a few joules to mega joules to understand the thrust performance both for small-scale experiments and for full-scale fusion rockets. We find that the momentum efficiency does not depend on the propellant mass, material, and plasma energies, and the impulse bit is expressed as the power-law of the plasma energy and mass. These relations are important for designing missions and for estimating the thrust of fusion rockets.","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135865354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shishir PUROHIT, Manoj K. GUPTA, Malay B. CHOWDHURI, Umesh NAGORA, Yashika TAUNK, Abhishek KUMAR, Kajal GARG, Surya K. PATHAK, Kumarpalsinh A. JADEJA, Rohit KUMAR, Kumudni TAHILIANI, Sameer KUMAR, Kaushal M. PATEL, Rakesh L. TANNA, Supriya A. NAIR, Joydeep GHOSH
{"title":"Investigation of Temporal Evolution of Hard X-Ray Spectrum from Neon-Seeded Plasma of ADITYA-U Tokamak","authors":"Shishir PUROHIT, Manoj K. GUPTA, Malay B. CHOWDHURI, Umesh NAGORA, Yashika TAUNK, Abhishek KUMAR, Kajal GARG, Surya K. PATHAK, Kumarpalsinh A. JADEJA, Rohit KUMAR, Kumudni TAHILIANI, Sameer KUMAR, Kaushal M. PATEL, Rakesh L. TANNA, Supriya A. NAIR, Joydeep GHOSH","doi":"10.1585/pfr.18.2402079","DOIUrl":"https://doi.org/10.1585/pfr.18.2402079","url":null,"abstract":"The adverse effect associated with runaway electrons (RE) requires the temporal monitoring of the Hard X-ray (HX) spectrum produced by RE. This enables us to know the photon flux corresponding to a particular energy of HX in temporal space. A Lanthanum Bromide (LaBr3)-based HX spectrometer system (80 keV ∼ 5 MeV) is routinely operated on the ADITYA-U tokamak for monitoring the temporal evolution of the HX spectrum. The temporal evolutions of the HX energy having maximum count and the average RE temperature (RE average energy) have been analyzed for the plasmas injected with neon (Ne) impurity. It has been found that peak energy and average runaway energy reduces significantly after the Ne gas puffand this reduction happens when the electron density rises after the Ne gas puff. The RE temperature values were ∼ 620 KeV and 230 KeV before and after the Ne injection, respectively. The spectral shape, in both counts and energy, shrunk drastically, suggesting the reduction of the HX emission after the Ne gas puffing.","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135865355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of the Contribution of Magnetic Moment Conservation to Ion Energy Transport in the GAMMA 10/PDX Divergent Field Region","authors":"Kosuke TAKANASHI, Satoshi TOGO, Naomichi EZUMI, Mafumi HIRATA, Tsukasa SUGIYAMA, Naoki SHIGEMATSU, Takumi SETO, Takuma OKAMOTO, Satoshi TAKAHASHI, Kunpei NOJIRI, Mizuki SAKAMOTO","doi":"10.1585/pfr.18.2402081","DOIUrl":"https://doi.org/10.1585/pfr.18.2402081","url":null,"abstract":"We investigated the contribution of magnetic moment conservation to ion energy transport in the divergent magnetic field region, using the GAMMA 10/PDX end region to simulate scrape-offlayer (SOL) plasmas in DEMO reactors. The averaged parallel energy increments (∆E∥) were measured by performing energy analyses at two points: upstream and downstream of the GAMMA 10/PDX end region. A newly developed retarding field analyzer (RFA) was inserted upstream of the end region to perform energy analyses. Assuming that only effects of potential difference (∆Eϕ) and magnetic moment conservation (∆E⟨µ⟩) affect ∆E∥, the contribution of magnetic moment conservation to ion energy transport was deduced. These results suggested that ∆E⟨µ⟩< ∆Eϕ irrespective of the difference in the diamagnetism at the central cell of GAMMA 10/PDX.","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135865353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metastable Oxides with Magnetic Functionalities","authors":"Katsuhisa Tanaka","doi":"10.1585/pfr.18.2101078","DOIUrl":"https://doi.org/10.1585/pfr.18.2101078","url":null,"abstract":"","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47357394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Mishra, P. Panchal, S. Mukherjee, Vishal Gupta, H. Agravat, P. Nayak, R. Gangradey
{"title":"Development of a Fast Valve Assisted Mechanical Launcher for Cryogenic Pellets","authors":"J. Mishra, P. Panchal, S. Mukherjee, Vishal Gupta, H. Agravat, P. Nayak, R. Gangradey","doi":"10.1585/pfr.18.2405076","DOIUrl":"https://doi.org/10.1585/pfr.18.2405076","url":null,"abstract":"Plasma fueling and disruption mitigation (DM) are two of the many key aspects in the successful operation of high-temperature fusion devices. Pellets of di ff erent gases like hydrogen, its isotopes, neon, and argon solid-ified at cryogenic temperature are used for fuelling and DM studies. A gas gun-based pellet injector has been developed for the large-size pellet formation and shattering study. Instead of the conventional fast valve injection mechanism, a new technique called mechanical pellet launching system (MPL) has been developed and tested for pellet launching. The MPL is a fast valve-driven pneumatic punch. The advantage of using it over the conventional technique is, the required impulse to dislodge the pellet can be achieved at lower propellant pressure. Before applying to the cryogenic pellets, the MPL has been tested up to 4 MPa pressure on a test bench, and a punch speed of 2 - 12 m / s has been achieved for 0.2 - 4 MPa pressure. The developed MPL has been successfully applied on 6.2 mm l p × 4.2 mm d p cylindrical hydrogen pellets. Details of the pellet formation device, MPL system, and experimental results are presented in this paper.","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43624929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Hiwatari, Y. Someya, H. Utoh, Yoshiteru Sakamoto
{"title":"Unlimited Fusion-Energy Station Based on Lithium Recovery from Seawater for a Net-Zero Carbon World","authors":"R. Hiwatari, Y. Someya, H. Utoh, Yoshiteru Sakamoto","doi":"10.1585/pfr.18.1205077","DOIUrl":"https://doi.org/10.1585/pfr.18.1205077","url":null,"abstract":"","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44882810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naoki Matsumura, T. Johzaki, Wookyung Kim, Takuma Endo
{"title":"Effect of Kilo-Tesla Magnetic Fields on Ignition and Burn Dynamics in Fast Ignition Laser Fusion","authors":"Naoki Matsumura, T. Johzaki, Wookyung Kim, Takuma Endo","doi":"10.1585/pfr.18.2404061","DOIUrl":"https://doi.org/10.1585/pfr.18.2404061","url":null,"abstract":"","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49199234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takahiro Ijima, Shota Sakurai, Fumiya Takahashi, S. Ebara, H. Hashizume
{"title":"Feasibility Study on Liquid Divertor Using Molten Salt Free Surface Flow with Turbulent Promoters","authors":"Takahiro Ijima, Shota Sakurai, Fumiya Takahashi, S. Ebara, H. Hashizume","doi":"10.1585/pfr.18.2405075","DOIUrl":"https://doi.org/10.1585/pfr.18.2405075","url":null,"abstract":"A liquid Flibe divertor is proposed as a fusion DEMO reactor divertor that can suppress the surface temperature with low velocity through turbulent promoters, which are necessary considering the low heat transfer performance of liquid Flibe. Using water as a simulant fluid, a pebble-sunk structure (PSS) is introduced herein as a turbulent promoter. The heat transport characteristic is evaluated by flow visualization and heat transport experiments. The experimental results show that the kinetic energy and the heat transport near the free surface are enhanced when the PSS is introduced","PeriodicalId":20247,"journal":{"name":"Plasma and Fusion Research","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46133117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}