We present the High-Rigidity Spectrometer (HRS) planned at the Facility for Rare Isotope Beams (FRIB). The current status of the layout and the ion-optical design of the HRS is discussed.

The Material Plasma Exposure eXperiment (MPEX), which has completed its final design, is a new linear plasma device to advance the understanding of plasma-material interactions through the generation and delivery of plasmas as they are expected in future fusion reactor divertors. MPEX will be a steady-state device to study high-fluence exposures of plasma-facing materials and components. The requirements for the magnetic field at the heating stages and the target make the application of superconducting coils necessary. The final designs for the superconducting magnets have been developed using three cryostat designs with warm bore diameters of 65 cm and 156 cm. The large bores are required to for other systems such as vacuum, water cooling, and RF power. There are 19 superconducting coils in MPEX that are contained in six cryostats. Although design, fabrication, and testing for the magnets as stand-alone units are straightforward, challenges will arise during the integration of the system. Various field profiles will be used during operation. The magnetic field where the electron cyclotron heating occurs needs to operate at both 1.25 and 2.50 T. Analyses that have been performed on the final design include designing the coils and determining operating currents to meet field requirements, forces between cryostats, the effects of coil and/or cryostat movement, and quench analysis. To ensure that the magnetic field requirements are met, a plan for monitoring the magnetic field at specified locations has been developed which includes the effect of coil and/or cryostat movement.

The Material Plasma Exposure eXperiment (MPEX) has been proposed as a facility to address plasma material interaction knowledge gaps to qualify and develop materials and technologies that surround plasma environments for future fusion reactors. Utilizing different radio-frequency (rf) heating technologies, MPEX is a linear plasma device that will generate fusion reactor-like plasmas with energies and particle fluxes at the target materials with electron temperatures of 1 to 15 eV, electron densities of 10 20 to 10 21 m -3 , and ion fluxes greater than 10 24 m -2 s -1 . Starting with the MPEX requirements with respect to magnetic fields between 0.1 and 2.5 T and warm bores of either 0.65 m or 1.56 m, conceptual designs for a superconducting magnet system have been developed that utilize multiple NbTi windings distributed across seven cryostats to accommodate rf heating, water cooling, and vacuum systems needed for MPEX. While the cryogenic and magnet technologies relative to the field and space requirements are mature, the integration of these technologies across multiple cryostats presents several technical and logistical challenges. An analysis of the preferred refrigeration approach, modular recondensing liquid helium cryocoolers, was performed. Utilizing a design margin of a factor of two, this approach is feasible within the current design requirements for MPEX with some considerations related to its implementation within the thermal shields and the magnet subsystem geometries.

To advance the understanding of plasma material interactions, the Material Plasma Exposure eXperiment (MPEX) is a new linear plasma device that will generate and deliver plasma relevant to future fusion reactor divertors. The operation of MPEX is planned to be steady-state in order to facilitate high fluence exposures of plasma facing materials and components. The desire for steady-state operation along with the magnetic field requires the utilization of superconducting coils. The superconducting magnet system for MPEX has been developed. The baseline model has six superconducting magnet and one room-temperature magnet subsystems. In order to protect multiple superconducting magnet systems, quench analysis was carried out to determine the best protection approach for each magnet type. Because the mutual inductance accounts for approximately 35% of the stored energy in the entire system, this must be considered when determining the peak voltages and temperatures during a quench. Two approaches for passive quench protection are considered: (1) self-protecting magnets and (2) use of diodes to sub-divide the coils. For both approaches, active quench detection will be used to ensure all coils are de-energized in the event of a quench. Results of the quench analysis for several quench scenarios are presented.

The Facility for Rare Isotope Beams (FRIB) project fully utilizes superconducting cavities from a low energy: β=0.041 and 0.085 quarter-wave resonators (QWRs) and β=0.29 and 0.53 half-wave resonators (HWRs). Following the QWR, a β=0.53 pre-production cryomodule was assembled and cold tested as the first FRIB HWR cryomodule. The HWR cryomodule includes many different design features compared to the QWR. However, all cavities achieved and locked at the design field of 7.4 MV/m within phase and amplitude specifications. A total dynamic load of 33 W was sufficiently smaller than the specification of 63 W, and no Q0 degradation was observed. An 8-T superconducting solenoid functioned as designed, and the degaussing procedure worked properly. This successful cold test allows for the start of production of HWR cryomodules for the next step.

The Facility for Rare Isotope Beams (FRIB) is a continuous wave heavy ion beam linear accelerator. FRIB consists of 322 low/medium beta superconducting radio frequency (SRF) cavities in 48 cryomodules operating at 2 K. FRIB cryomodules utilize 70 8-T-superconducting solenoid packages for beam focusing and steering which operate at 4.5 K with a margin of +0.5 K [1]. Each package includes an 8-T main coil for beam focusing, a pair of bucking coils to reduce the high fringe field on the local magnetic shield of the cavities, and two sets of steering (dipole) coils for X and Y directions to correct beam direction due to transverse kicks it received in SRF cavities. The solenoid package is all made of superconducting (NbTi) wires. In this paper, the solenoid package design, fabrication, and testing results are presented.

The Facility for Rare Isotope Beams' heavy ion continuous-wave (CW) linac extends superconducting RF to low beam energy of 500 keV/u. 332 low-beta cavities are housed in 48 cryomodules. Technical development of high performance subsystems including resonator, coupler, tuner, mechanical damper, solenoid and magnetic shielding is necessary. In 2015, the first innovatively designed FRIB bottom-up prototype cryomodule was tested meeting all FRIB specifications. In 2016, the first full production cryomodule is constructed and tested. The preproduction and production cryomodule procurements and in-house assembly are progressing according to the project plan.

Recently we tested the first two cryomodules for FRIB, which contain β = 0.085 superconducting quarter-wave resonators and superconducting solenoid packages. Their performance was successfully validated under realistic conditions. This paper reports the solenoid package tests results.

The Facility for Rare Isotope Beams (FRIB) is based upon a high power heavy ion driver linac under construction at Michigan State University under a cooperative agreement with the US DOE. The construction of conventional facilities already started in the summer, 2013, and the accelerator production began from the summer, 2014. FRIB will accelerate all the stable ion beams from proton to uranium beyond a beam energy of 200 MeV/u and up to a beam power of 400 kW to produce a great number of various rare isotopes using SRF linac. The FRIB SRF driver linac makes use of four kinds of SRF structures. Totally 332 two gap cavities and 48 cryomodules are needed. All SRF hardware components have been validated and are now moving to production. The SRF infrastructure also has been constructed in MSU campus. This talk will present FRIB project and challenges regarding SRF technologies. The status of SRF linac hardware validation and their production, SRF infrastructure status and plan shall be addressed. The information that can be relevant for future large scale proton/ion SRF linacs will also be provided.

The Facility for Rare Isotope Beams under construction at Michigan State University, a new national user facility funded by the U. S. Department of Energy Office of Science will provide exotic rare isotope beams at energies of at least 200 MeV/u at a beam power of 400 kW. The proposed FRIB fragment separator has a preseparator consisting of the hot-cell and vertical section in the first stage followed by two more stages. Two large high performance dipole magnets with a 50° bend are required in the vertical section of the preseparator. Both cost and space constraints in the vertical section along with technical scope have pushed the requirement of the superconducting dipole peak field to 2.0 T. The design of a large magnetic gap (0.2 m), superferric dipole with magnetic rigidity as high as 8 T-m and effective length of 3.49 m is presented. The current design is a “warm iron” H-shaped magnet with nominal yoke length of 3.39 m and magnetic half-gap of 0.10 m. The major challenges are tight spaces in the vertical section, the compact coil and cryostat design and the unbalanced forces. The coil design is based on wet wound epoxy impregnated Formvar insulated conductor that provides ample current and temperature margins. This paper also presents the detailed magnet design including coil forces, coil restraint system, coil properties, conductor stability, quench analysis and full mechanical details.

One of the challenges in the Facility for Rare Isotope Beams at Michigan State University is the 30 degree bending dipoles in the fragment separator operating in a high radiation environment. It is known that high temperature superconductors (HTS) have a much larger thermal margin due to high critical temperature $>$ 90 K and high upper critical field $>$ 100 T, which allows HTS magnets to operate stably so as to tolerate very high heat loads due to radiation. The HTS dipole magnets will utilize ReBCO conductor technology and operate at 38 K cooled by helium gas. High radiation deposits a large amount of heat into the iron yoke, cryostat, bobbin and HTS coil itself. For certain beams, over-bent particles will hit the cryostat with high intensity in the beam down-stream. Another difficulty is that the dipole coils generate significant Lorentz forces that need to be contained. All of these challenges have been analyzed separately and then integrated to find novel approaches. These approaches have been applied to optimize the magnet structure and enhance the 38 K helium gas cooling system. We present project status and progress of this HTS ReBCO dipole magnets and lay out a plan for magnet manufacturing.

A superconducting solenoid-based focusing lens was designed and built for use in the SSR1 cryomodule of PXIE test facility at FNAL. As the cryomodule contains superconducting spoke-type cavities, one of main goals during design stage was minimization of magnetic field on walls of the cavities. The design also attempted minimization of the uncertainty of the magnetic axis position in the lens. This report describes main features of the design and summarizes results of performance tests and magnetic axis position measurements.

The use of high-temperature superconductors (HTS) for cryogen-free gyrotron magnets will greatly reduce the power requirement and overall physical size of the system. Because some gyrotron systems are mounted on a vehicle and need to be mobile, the refrigeration system must be as lightweight and compact as possible. Cryomagnetics previously built a BSCCO magnet based on the design of a NbTi magnet. The limiting factors with this magnet were the cost of the BSCCO material and the excessive weight due to the necessity of field-shaping iron. Since it is projected that the cost of 2G YBCO tape will become significantly lower than BSCCO, and the critical current will also increase, the next generation of these magnets will mitigate those problems. The first objective was to study quench behavior in HTS coils. Cryomagnetics has also designed, built and successfully tested a 3.57 T magnet wound with 2G YBCO tape. This is the first full-scale magnet of its kind built using 2G YBCO tape. It consists of 10 double-pancakes operating at 140 A and 20 K. A single-stage cryocooler is used to cool the magnet. Because the performance of YBCO material is improving quickly, future magnets will be able to operate at lower current, higher temperature and will be lighter weight.

Cryomagnetics' new “C-Mag Optical” Magneto-Optic Property Measurement System is a versatile materials and device characterization system that allows the researcher to simultaneously control the applied magnetic field and temperature of a sample while studying its electrical and optic properties. The system integrates a totally liquid cryogen-free 6T superconducting split-pair magnet with a variable temperature sample space, both cooled using a single 4.2K pulse tube refrigerator. To avoid warming the magnet when operating a sample at elevated temperatures, a novel heat switch was developed. The heat switch allows the sample temperature to be varied from 10K to 300K while maintaining the magnet at 4.2K or below. In this paper, the design and performance of the overall magnet system and the heat switch will be presented. New concepts for the next generation system will also be discussed.

A program is currently under way to develop a compact, power-efficient, robust gyrotron. Gyrotrons require a very precise magnetic field, typically generated by a NbTi superconducting magnet, to form the environment necessary for the microwave power generation. The use of high-temperature superconductor (HTS) material for a liquid cryogen-free gyrotron magnet will significantly reduce the input power requirements for the cryocooler compressor and the overall size of the magnet system. Cryomagnetics has designed, built and successfully tested a magnet wound with BSCCO-2223 tape to be used in the gyrotron. The HTS magnet was designed such that it can replace the current LTS (NbTi) cryogen-free gyrotron magnet in form, fit and function. The HTS magnet consists of 11 double-pancakes and provides stable 3.57 T operation at 37 K with a current of 120 A. Magnetic field shape, which is extremely important in gyrotron applications, was a considerable challenge since NbTi operating at 4.2 K is capable of a much higher current density than BSCCO operating at 37 K. Overall refrigeration requirements were reduced from /spl sim/8 kW in the LTS system to /spl sim/4 kW in the HTS system. A single-stage GM cryocooler was used to cool the HTS magnet. Comprehensive tests of the HTS magnet, including operation with the gyrotron tube, have been successfully completed.

Superconducting low-beta quadrupole magnets for the LHC insertion regions are being developed at KEK as part of the collaboration between CERN and KEK. Magnet production technology developed at KEK has been transferred to a manufacturer of production magnets. In order to verify the production technology, fabrication jigs, tools, and procedures, the first full-scale prototype, MQXA-P1, was fabricated. Mechanical characteristics of MQXA-P1 were measured during magnet assembly process, and it satisfied specifications needed for the production magnets. Validity of the magnet design and fabrication method was confirmed.

LHC low-beta quadrupole magnets are being developed at KEK as part of the collaboration between CERN and KEK. Based on R&D progress of five 1-m long: model magnets, a full-scale 6.7-m long prototype was developed and excitation tests were performed at KEK. A magnet protection scheme for the full-scale magnet is very important in case of the quench because a large stored energy has to be fully dissipated into the coils. The quench protection system which consists of heaters and power supplies was examined in a series of heater tests for the prototype. It was concluded that the quench protection system will protect the production magnet even in the worst quench situation.

High gradient 70 mm aperture superconducting low-beta quadrupole magnets have been developed at KEK as part of the collaboration between CERN and KEK for the Large Hadron Collider (LHC). After development of two I m model magnets, the third model magnet with the new coil design was built and excitation tests were completed. The third model successfully reached the design field gradient of 240 T/m and showed training memory after full thermal cycles. Other quench tests were performed and it was verified that the third model exhibited reliable quench performance and sufficient safety margin during operation.

Development of low-/spl beta/ quadrupole magnets for the LHC beam interaction regions has been carried out. The magnet is designed with a field gradient of 240 T/m in a coil aperture of 70 mm, and is to be operated at /spl les/215 T/m with absorption of beam loss heating. Three 1-m models with the final design have been developed and tested with satisfying requirements of field quality and training characteristics. A full-scale (6.3-m) prototype has been developed, and is being tested. Progress of the LHC low-/spl beta/ quadrupole development at KEK is reported.