Development of the Magnetically Floating Superconducting Dipole in the RT-1 Plasma Device

Mizumaki, S.; Tosaka, Taizo; Ohtani, Y.; Ono, M.; Kuriyama, T.; Nakamoto, K.; Tachikawa, N.; Ioka, S.; Morikawa, Junji; Ogawa, Yuichi; Yoshida, Zensho

doi:10.1109/tasc.2006.873315

Cited by 11 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. The HTS floating magnet consists of an HTS coil, a PCS, measuring feedthroughs, a cooling tube that is jointed with transfer tubes for circulating gas helium, a pair of current leads that has demountable joints, a thermal shield and a vacuum vessel [4].…”

Section: Persistent-current Coil Designmentioning

confidence: 99%

“…Persistent-current operation tests were conducted at the constant temperatures of 20 K, 30 K and 35 K. Tests at 35 K were conducted because we supposed that the HTS coil temperature would rise up to 35 K after a levitation experiment was finished at 30 K [4]. Test results are summarized in Table III.…”

Section: B Persistent-current Operation Testsmentioning

confidence: 99%

“…RT-1 is an internal coil device in which a high temperature superconducting (HTS) floating magnet is levitated in a plasma vacuum vessel [4]. Plasma is confined by a dipole magnetic field produced by the HTS floating magnet.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Development of Persistent-Current Mode HTS Coil for the RT-1 Plasma Device

Tosaka

Ohtani

Ono

et al. 2006

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

The plasma confinement device "RT-1" which had a high temperature superconducting (HTS) floating magnet was constructed for advanced high-beta plasma and fusion research at the University of Tokyo. The high temperature superconducting (HTS) floating magnet is magnetically levitated inside the plasma vacuum vessel. Plasma is confined by a magnetic dipole field around the HTS floating magnet. The HTS floating magnet is operated in persistent-current mode and it consists of an HTS coil, an HTS persistent-current switch (PCS), a pair of demountable joints of current leads, detachable joints of a cooling tube, a thermal shield and a vacuum vessel. The HTS coil and the PCS and the thermal shield are cooled below 20 K by a flow of helium gas through the cooling tube. The floating HTS magnet is designed to operate in the temperature range from 20 K to 30 K without being cooled while it is levitated. We fabricated a persistent-current HTS coil that consists of the HTS coil and the PCS. Persistent-current operations and protection tests were conducted with the persistent-current HTS coil before it was mounted in the floating magnet cryostat. The current-decay rate was 0.9% in an 8 hour operation. The coil energy was safely discharged by inducing PCS quench in a protection test.

show abstract

Section: Persistent-current Coil Designmentioning

confidence: 99%

Section: B Persistent-current Operation Testsmentioning

confidence: 99%

See 1 more Smart Citation

Development of Persistent-Current Mode HTS Coil for the RT-1 Plasma Device

Tosaka

Ohtani

Ono

et al. 2006

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this coil, Ag-sheathed Bi-2223 tape was used, which was the only available HTS at that time. The larger RT-1 device was built in 2006 using improved Bi-2223 tape, and stable levitation for more than 6 hours was achieved [5,6]. Recently, the floating coil of the Mini-RT was upgraded using the latest GdBCO tape for better per- formances [7,8].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of HTS Magnet Option for Fusion Reactors

Yanagi

Terazaki

Natsume

et al. 2014

Plasma and Fusion Research

View full text Add to dashboard Cite

Conceptual design studies are being carried out on the application of high-temperature superconducting (HTS) conductors and coils to the magnet systems of fusion reactors. A 100-kA-class HTS conductor is required to be applied at high magnetic fields of > 12 T. A simple stack of YBCO tapes embedded in copper and stainless-steel jackets is found to be a practical approach to producing large-scale conductors that exhibit high cryogenic stability and mechanical rigidity. The feasibility of the segmented fabrication method for large complex HTS coils, such as the helical coils in the LHD-type helical fusion reactor FFHR-d1, is being investigated by developing mechanical bridge-type lap joint technology of HTS conductors.

show abstract

“…Inside the vacuum chamber, RT-1 has a Bi-2223 high-temperature superconducting dipole field magnet. 25 The dipole field magnet is levitated in order to minimize perturbations to the plasma. The vertical position of the superconducting magnet is monitored by three laser sensors, and a levitation magnet, located at the top of the chamber, is feedback-controlled to realize stable coil levitation.…”

Section: Introductionmentioning

confidence: 99%

Formation of high-β plasma and stable confinement of toroidal electron plasma in Ring Trap 1

et al. 2011

Self Cite

View full text Add to dashboard Cite

Formation of high-b electron cyclotron resonance heating plasma and stable confinement of pure electron plasma have been realized in the Ring Trap 1 device, a magnetospheric configuration generated by a levitated dipole field magnet. The effects of coil levitation resulted in drastic improvements of the confinement properties, and the maximum local b value has exceeded 70%. Hot electrons are major component of electron populations, and its particle confinement time is 0.5 s. Plasma has a peaked density profile in strong field region [H. Saitoh et al., 23rd IAEA Fusion Energy Conference EXC/9-4Rb (2010)]. In pure electron plasma experiment, inward particle diffusion is realized, and electrons are stably trapped for more than 300 s. When the plasma is in turbulent state during beam injection, plasma flow has a shear, which activates the diocotron (Kelvin-Helmholtz) instability. The canonical angular momentum of the particle is not conserved in this phase, realizing the radial diffusion of charged particles across closed magnetic surfaces.

show abstract

Development of the Magnetically Floating Superconducting Dipole in the RT-1 Plasma Device

Cited by 11 publications

References 5 publications

Development of Persistent-Current Mode HTS Coil for the RT-1 Plasma Device

Development of Persistent-Current Mode HTS Coil for the RT-1 Plasma Device

Feasibility of HTS Magnet Option for Fusion Reactors

Formation of high-β plasma and stable confinement of toroidal electron plasma in Ring Trap 1

Contact Info

Product

Resources

About