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Good magnetic surfaces, as opposed to magnetic islands and chaotic field lines, are generally desirable for stellarators. In previous work, M. Landreman et al. [Phys. of Plasmas 28, 092505 (2021)] showed that equilibria computed by the…

Plasma Physics · Physics 2022-04-26 A. Baillod , J. Loizu , J. P. Graves , M. Landreman

Self-compensated comagnetometers, employing overlapping samples of spin-polarized alkali and noble gases (for example K-$^3$He) are promising sensors for exotic beyond-the-standard-model fields and high-precision metrology such as rotation…

We perform metastability exchange optical pumping of helium-3 in a strong magnetic field of 1.5 T. The achieved nuclear polarization, from 80% at 1.33 mbar to 25% at 67 mbar, shows a substantial improvement at high pressures with respect to…

Atomic Physics · Physics 2009-09-29 Marie Abboud , Alice Sinatra , Xavier Maitre , Genevieve Tastevin , Pierre-Jean Nacher

Global gyrokinetic simulations find a strong helically-trapped electron mode (HTEM) driven by density gradients in the optimized stellarator W7-X fusion experiment. The eigenmode structure localizes in the inner side of the torus with an…

Plasma Physics · Physics 2023-10-12 Javier H Nicolau , Xishuo Wei , Pengfei Liu , Gyungjin Choi , Zhihong Lin

Radiative corrections due to pair production in process of electron-positron annihilation are considered. The main attention is paid to the corrections of the third order. Simultaneous emission of photons and pairs is taken into account.…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. B. Arbuzov

In neutron interferometric experiments using polarized neutrons coherent spin-rotation control is required. In this letter we present a new method for Larmor spin-rotation around an axis parallel to the outer guide field using topology…

We introduce a novel approach for the simultaneous optimization of plasma physics and coil engineering objectives using fixed-boundary equilibria that is computationally efficient and applicable to a broad range of vacuum and finite plasma…

Plasma Physics · Physics 2023-06-21 R. Jorge , A. Goodman , M. Landreman , J. Rodrigues , F. Wechsung

A four-field-period quasi-isodynamic stellarator configuration is presented that exhibits small neoclassical and electrostatic turbulent transport, good fast-ion confinement over a wide range of $\beta$ values, small bootstrap current and…

Plasma Physics · Physics 2025-12-10 E. Sánchez , J. L. Velasco , I. Calvo , J. M. García-Regaña , C. Salcuni , J. A. Alonso

Stellarators are fusion energy devices that confine a plasma using non-axisymmetric magnetic fields. Complex coils with tight construction tolerances are needed to create such fields. To simplify such coils, we use a method here to create…

Plasma Physics · Physics 2025-05-13 J. Biu , R. Jorge

Spatial light modulators are widely used to perform modulations of different properties of the electromagnetic field. In this work, a simple optimization method for general double-pass setups was developed. It takes into account the…

Optics · Physics 2022-02-09 Sebastián Bordakevich , Lorena Rebón , Silvia Ledesma

Rigid electron rotation of a fully penetrated Rotamak-FRC produces a pressure flux function that is more peaked than the Solov'ev flux function. This paper explores the implications of this peaked pressure flux function, including the…

Plasma Physics · Physics 2021-08-11 C. P. S. Swanson , S. A. Cohen

Materials to be deployed in space applications have to undergo a variety of different test scenarios, simulating actual space conditions. Among these materials solar photovoltaic cells, optics, meta-materials and more will be directly…

A three terminal nanoscale refrigeration concept based on a vibron-coupled quantum dot hybrid system coupled to two electronic reservoirs and a phonon bath is proposed and analyzed in detail. While investigating the non-trivial role of…

Mesoscale and Nanoscale Physics · Physics 2021-02-03 Swarnadip Mukherjee , Bitan De , Bhaskaran Muralidharan

The electron cooler of the CRYRING@ESR storage ring at the GSI-FAIR accelerator complex is a unique instrument, which not only provides beam cooling of the stored ions, but also serves as a low-energy electron target for Dielectronic…

In this paper we introduce a new concept of atoms on discrete sets to develop an advanced method to find a particular solution for higher-order non-homogeneous Cauchy-Euler equations. The proposed method provides also an approximate…

Analysis of PDEs · Mathematics 2026-04-14 Miloud assal , Skander Belhaj

We optimize a collision-induced cooling process for ultracold atoms in the nondegenerate regime. It makes use of a Feshbach resonance, instead of rf radiation in evaporative cooling, to selectively expel hot atoms from a trap. Using…

Quantum Gases · Physics 2015-04-29 Marlon Nuske , Eite Tiesinga , L. Mathey

To measure the mass of the electron neutrino, the "Electron Capture in Holmium-163" (ECHo) collaboration aims at calorimetrically measuring the spectrum following electron capture in $^{163}$Ho. The success of the ECHo experiment depends…

Instrumentation and Detectors · Physics 2019-05-23 Tom Kieck , Sebastian Biebricher , Christoph E. Düllmann , Klaus Wendt

Kontar et al. (2004) have shown how to recover mean source electron spectra in solar flares through a physical constraint regularization analysis of the bremsstrahlung photon spectra that they produce. They emphasize the use of non-square…

Astrophysics · Physics 2009-11-10 E. P. Kontar , A. G. Emslie , M. Piana , A. M. Massone , J. C. Brown

An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main…

Accelerator Physics · Physics 2015-11-17 Daniel Noll , Giulio Stancari

We study the nonequilibrium steady state of a mechanical resonator in the quantum regime realized by a suspended carbon nanotube quantum dot contacted by two ferromagnets. Because of the spin-orbit interaction and/or an external magnetic…

Mesoscale and Nanoscale Physics · Physics 2014-07-24 Pascal Stadler , Wolfgang Belzig , Gianluca Rastelli