A5045474567- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Physics of Superconductivity and Magnetism
- Electric Motor Design and Analysis
- HVDC Systems and Fault Protection
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Quantum Computing Algorithms and Architecture
- Superconductivity in MgB2 and Alloys
- Magnetic Properties and Applications
- Solid State Laser Technologies
- Cardiac Structural Anomalies and Repair
- Electromagnetic Simulation and Numerical Methods
- Neural Networks and Reservoir Computing
- Electromagnetic Scattering and Analysis
- Spacecraft and Cryogenic Technologies
- Silicon Carbide Semiconductor Technologies
- Laser Material Processing Techniques
- Glass properties and applications
- Magnetic confinement fusion research
- Magnetic Properties of Alloys
- Electromagnetic Launch and Propulsion Technology
IQM (Finland)
2022-2023
European Organization for Nuclear Research
2010-2022
Lawrence Berkeley National Laboratory
2021
Fermi National Accelerator Laboratory
2021
Aalto University
2020
Tampere University
2020
Keskuslaboratorio
2020
Outotec (Finland)
2016-2020
University of Turku
2012
Tunable coupling of superconducting qubits has been widely studied due to its importance for isolated gate operations in scalable quantum processor architectures. Here, we demonstrate a tunable qubit-qubit coupler based on floating transmon device, which allows us place at least 2 mm apart from each other while maintaining over 50-MHz between the and qubits. In introduced tunable-coupler design, both qubit-coupler couplings are mediated by two waveguides instead relying direct capacitive...
We studied the resistivity of rare-earth permanent-magnet materials over temperature range -40°C to +150°C. investigated three different from four manufacturers, including Nd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Fe xmlns:xlink="http://www.w3.org/1999/xlink">14</sub> B, SmCo xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> , and Sm Co xmlns:xlink="http://www.w3.org/1999/xlink">17</sub> measured their resistivities...
The CERN Large Hadron Collider (LHC) is envisioned to be upgraded in 2020 increase the luminosity of machine. major upgrade will consist replacing NbTi quadrupole magnets interaction regions with larger aperture magnets. Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn technology preferred option for this upgrade. critical current density J xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> strands have reached sufficiently high...
With the successful test of first two pre-series magnets US HL-LHC Accelerator Upgrade Project has started production MQXFA to be used in Q1/Q3 inner triplet elements HL-LHC. This good start comes after prototypes with limited performance, and it demonstrates importance learning from past issues. Therefore, this paper we want share most important lessons learned so far, focusing on those which may more interesting for similar projects. We will also present status fabrication US.
In the framework of EuCARD program, CERN is participating in development a 13 T 100-mm-aperture dipole magnet to upgrade superconducting cable test facility FRESCA at CERN. The conductor candidates for building this are two 1-mm Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn strands: Powder Tube (PIT) produced by Bruker-EAS and 132/169 RRP Oxford Superconducting Technology (OST). Recently PIT strand has been extensively...
The High-Luminosity project (HL-LHC) of the CERN Large Hadron Collider (LHC), requires low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\beta$</tex-math></inline-formula> * quadrupole magnets in Nb notation="LaTeX">$_\text{3}$</tex-math></inline-formula> Sn technology that will be installed on each side ATLAS and CMS experiments. After a successful short-model magnet manufacture test campaign, has...
In the framework of US LHC Accelerator Program (LARP), three laboratories BNL, FNAL and LBNL are developing Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn quadrupole magnets for Large Hadron Collider (LHC) luminosity upgrade. At present CERN is supporting this activity by testing some LARP 1 m long 90 mm aperture magnets. Recently two using a shell based key bladder technology (TQS) have been tested at CERN. These (TQS02c, TQS03a)...
Abstract The High Luminosity Large Hadron Collider (LHC) Project target is to reach an integrated luminosity of the LHC 3000 fb −1 , corresponding a factor 10 increase in collisions with respect current accelerator. One main components superconducting quadrupole called MQXF. It based on Nb 3 Sn technology and has 150 mm single aperture field gradient 132.6 T m . MQXF magnets are currently preseries production joint collaboration between CERN US-LHC Accelerator Upgrade Project. first...
In the framework of future LHC upgrades using Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn magnets, supported in part by US Accelerator Research Program (LARP) and European EuCARD program, CERN is intensifying its research on Rutherford cables. FRESCA cable test facility at CERN, two new samples were investigated concerning their quench critical current as well stability performance. The are based RRP type strands with...
The High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) is approaching the production phase of US-contributed Q1 and Q3 Interaction Region Quadrupoles (MQXFA). structures for MQXFA prototypes were designed inspected by US-LARP (LHC Research Program), AUP developed criteria, which will be used pre-series structures. first two full-length with 4.2 m magnetic length, MQXFAP1 MQXFAP2, assembled at Lawrence Berkeley National Laboratory (LBNL), tested Brookhaven (BNL). end aluminum short...
MQXF is the Nb3Sn Low-β Quadrupole magnet that HL-LHC project planning to install in LHC interaction regions 2026 as part of an upgrade increase integrated luminosity by about a factor ten. The will be fabricated two different lengths: 4.2 m for MQXFA, built US Accelerator Upgrade Project (AUP), and 7.15 MQXFB, CERN. In order qualify design characterize its performance with conductors, cable geometries pre-load configuration, five short model magnets, called MQXFS, were fabricated, assembled...
For the High Luminosity Upgrade project (HL-LHC) of CERN Large Hadron Collider (LHC), lower β* quadrupole magnets based on advanced Nb 3 Sn conductors will be installed each side ATLAS and CMS interaction points. To quantify endurance technological limits these magnets, beyond their maximum operational conditions, two short length model have been extensively tested at SM18 test facility. Both were subjected to eight thermal cycles. One them was trained its ultimate current (17.89 kA,...
Abstract The fast thermal and electromagnetic transients that occur in a superconducting magnet case of quench have the potential generating large mechanical stresses both coils structure. While investigation such loads should generally be conducted to ensure safe operation system, its importance is greatly enlarged high-field magnets based on strain sensitive superconductors. For these, rigorous analysis mechanics during becomes critical. scope this work hence bring, for first time,...
The magnetothermal instability (MTI) is an issue in the high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> Nb xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn superconducting strands for accelerator magnets. first kind of MTI magnetization instability, which may be significantly reduced by using small filaments and with a high copper residual resistivity ratio (RRR) ≥ 100....
MQXF is the Nb3Sn Low-β quadrupole magnet that HL-LHC project planning to install in LHC interaction regions 2026 increase integrated luminosity.The will be fabricated two different lengths: 4.2 m for MQXFA, built US by Accelerator Upgrade Project (AUP), and 7.15 MQXFB, CERN.In order qualify design characterize its performance with conductors, cable geometries pre-load configurations, five short model magnets, called MQXFS, were fabricated, assembled tested.We compare mechanical behavior of...
Magnetothermal instability may affect the performance of high critical current density Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn strands by quenching superconductor at values lower than its current. This phenomenon has important implications in design next-generation superconducting magnets for accelerators. According to theory, strand magnetothermal stability can be improved changing distribution within strand. In this...
Quantum computing has tremendous potential to overcome some of the fundamental limitations present in classical information processing. Yet, today's technological quality and scaling prevent exploiting its full potential. based on superconducting quantum processing units (QPUs) is among most promising approaches towards practical advantage. In this article basic approach IQM Computers described covering both QPU rest full-stack computer. particular, focus a 20-qubit computer featuring Garnet...
Finite element analysis of transformers with stranded conductors can be computationally heavy due to the fine mesh required for winding domains. In this paper, a domain decomposition method subdomain pre-processing is proposed overcome problem. order solve field-circuit problem finite analysis, modelled initially. Next, reduced matrix system obtained from formulation. The solution entire by solving formulation and separately. tested on transformer model in no load operation. Accurate...
Quasi-static electromagnetic problems involving, e.g., inductors, are often solved numerically using the finite-element method with magnetic vector and electric scalar potentials. Coupling inductors to external circuits may however, lead, large matrix equations that could become bottlenecks in parallel computation systems, particularly for strong scaling when more processors introduced scale down total time. It is argued shown by numerical simulations use of reduced support model improves...
Tunable coupling of superconducting qubits has been widely studied due to its importance for isolated gate operations in scalable quantum processor architectures. Here, we demonstrate a tunable qubit-qubit coupler based on floating transmon device which allows us place at least 2 mm apart from each other while maintaining over 50 MHz between the and qubits. In introduced tunable-coupler design, both qubit-coupler couplings are mediated by two waveguides instead relying direct capacitive...
In a dipole or in quadrupole accelerator magnet, the displacement of coil turns induced by electromagnetic forces can cause quenches limiting magnet performance. For this reason, an azimuthal preload is applied to avoid movements up required operational current. However, several tests showed that magnets operate with partial preload, i.e. unloading during ramp does not prevent reaching higher currents. This issue particularly relevant for Nb3Sn magnets, where loads filaments reach...