The Cryogenic System and Planned Cryogenic Tests For the Future High Luminosity LHC IT Magnet String

The high luminosity upgrade of the Large Hadron Collider will require the replacement of the triplet of final focusing superconducting magnets at interaction points 1 and 5 with a new set of helium II cooled magnets. To validate the technologies and assembly procedures and to investigate the collective effects, a string of magnets representative of the final HL-LHC configuration, will be installed in the SM18 test facility at CERN in 2021. The local cryogenic distribution connected to the string of magnets will also be representative of the final configuration. This paper first describes the cryogenic configuration of the magnet string and the functional cryogenic requirements for the operation and test program. The cryogenic parameters for the different circuits and operation phases are presented. The paper details the cryogenic test program foreseen to investigate the specific challenges of cooling Nb3Sn magnets and their beam screens during high heat load (several hundred watts at 1.9 K), steady state, and transient operation. The paper presents the complete cryogenic system planned for the string, its integration into the SM18 facility, the required adaptation of the SM18 cryogenic infrastructure, and the conceptual design of the main components

The Influence of Personality Type on Patient Outcome Measures and Therapeutic Alliance in Patients with Low Back Pain

Background: Low back pain (LBP) has been shown to have various biological, psychological, and social factors that affect prognosis. However, it is unclear how personality may influence self-reported outcome measures and therapeutic alliance (TA). Methods: Eysenck’s personality inventory was used to assess personality, while the numeric pain rating scale (NPRS), Oswestry Disability Index (ODI), Tampa Scale of Kinesiophobia (TSK), Global Rating of Change (GROC), and the Working Alliance Inventory (WAI) measured patient progress and relationship strength. All outcome measures were formulated in a single survey that both the therapist and patient completed electronically. Results: Sixty-seven patients with LBP and twenty-two licensed physical therapists participated. For personality measures, there was a significant positive correlation between neuroticism and GROC (rho = 0.295, p = 0.015) and a significant negative correlation between extraversion and WAI (rho = −0.243, p = 0.048). Significant correlations were found between ODI and TSK (rho = 0.462, p ≤ 0.001) and between ODI and GROC (rho = −0.416, p ≤ 0.001). A significant negative correlation was found between TSK and GROC (rho = −0.301, p = 0.013). Conclusions: Patients with higher levels of disability seemed to report higher levels of kinesiophobia and less overall improvement in physical therapy. Patients classified as neurotic reported higher levels of improvement while extraverted patients demonstrated a weaker therapeutic alliance with their therapist

A New Cryogenic Test Facility for Large and Heavy Superconducting Magnets

CERN has recently designed and constructed a new cryogenic facility for testing large and heavy superconducting magnets at liquid helium temperatures. The facility, erected in a large assembly hall with cranes capable of up to 100 t, provides a cooling capacity of 1.2 kW at 4.5 K equivalent, 15-kW LN$_2$ cooling and warming capabilities for up to three magnets in parallel. The facility provides the required technical infrastructure for continuous and reliable operation. Test capabilities comprise electrical, cryogenics, vacuum and mechanical verification, and validation at ambient and liquid helium temperatures. A comprehensive survey and magnetic measurement system, comprising a hall-probe mapper, a rotating-coil magnetometer, a stretched wire, a translating fluxmeter, and a laser tracker, allows the detailed measurement of the magnetic field strength and quality on a large volume. The magnetic axes of the quadrupoles can be established within $\pm 0.2$ mm at $1 \sigma$ accuracy. The facility has been equipped with power supplies, three converters of $\pm 500$ A/120 V, and six converters of $\pm 600$ A/40 V, as well as the required energy extraction, quench protection, data acquisition, and interlocks for the testing of superconducting magnets for the FAIR project, currently under construction at the GSI Research Center, in Darmstadt, Germany. The versatile design of the facility, its layout, and testing capabilities complements CERN's other test infrastructures for large superconducting magnets. We report on the design, construction, and commissioning of the facility as well as the expected capabilities and performances for future tests of large and heavy superconducting magnets