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Institute for Basic Science have been constructing Superconducting LINAC composed of quarter wave resonator (QWR) and half wave resonator (HWR). All QWR cavities have been completely fabricated and successfully tested to be assembled in QWR cryomodules. For now, we have been testing HWR cavities over 50%. For the testing period, the success rate experienced up and downs like we went through during the QWR tests. In many cases, we observed that some cavities did not reach requirement performance 2K although they showed high performance at 4K. We increased the temperature of heat treatment to cure the rapid Q drop at the high gradient and observed most cavities passed the test after heat treatment., Proceedings of the 20th International Conference on RF Superconductivity, SRF2021, East Lansing, MI, USA

All HWRs (half-wave resonator superconducting cavities) have been fabricated and installed in the low energy section of the LINAC in IBS. All HWR cavities have been tested (vertical tests, VT) both at 4.2 K and 2.1 K cryogenic surroundings although operating temperature of HWRs is 2.1 K. Good cavities of high quality factors showed the Q drop tendency of 2.1 k were very similar to that of 4.2 K. However, in many cases, Q drop tendency of 2.1 K were not similar with 4.2 K, rather Q decreased more rapidly than 4.2 K which means the surface resistance of the cavity rapidly increased at 2 K surrounding. In this study, we will report that various Q results of HWRs and compare their Q drop tendency as a function of temperature, 2.1 K and 4.2 K., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

RF test for quarter-wave resonator (QWR) and half-wave resonator (HWR) superconducting cavities is performed at low temperature. The quality factors of the superconducting cavities are measured as a function of accelerating field. The magnetic heating effect for the quarter-wave resonator (QWR) is studied. For the half-wave resonator (HWR), the Q slope degradation is investigated with x-ray radiation and field emission., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

The conservation of quality factor under relativistic motion is applied to the superconducting cavity as well as the heartbeat of mammal. The quality factor of the superconducting cavity is conserved under relativistic motion. The frequency of the cavity decreases and the decay time increases as the velocity and acceleration are increased. The quality factor of the superconducting cavity is comparable with the total heartbeat of the mammal. The quality factor for the heartbeat of the mammal representing the total number of heartbeat is also conserved under relativistic motion. Therefore, the heart rate is inversely proportional to the life expectancy under relativistic motion., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

Nuestro trabajo analiza experiencias obtenidas en la ejecución de la asignatura Proyecto de Licenciatura, para la carrera de Ingeniería Civil Industrial de la U. de Talca, durante los últimos 10 años. La asignatura se encuentra en el 8vo. semestre de la carrera y es la última asignatura que los estudiantes deben aprobar para la obtención del grado de Licenciado en Ciencias de la Ingeniería. La asignatura tiene por objetivo desarrollar un proyecto que integre conocimiento de los módulos previos de la carrera con énfasis en Gestión de operaciones, y que además fortalezca competencias transversales de investigación, trabajo en equipo y resolución de problemas. Los estudiantes trabajan en grupos, normalmente de tamaño 4, y seleccionan un problema del dominio con el cual trabajan durante todo el semestre. En este contexto, presentamos la estructura y metodología utilizada en el curso, además de experiencias obtenidas en diversos aspectos, como lo son: trabajo en grupos, asesoría del equipo de profesores a los grupos, generación de temas en los cuales se realizan los proyectos, importancia de búsquedas de información, relación con temas de innovación, actividades evaluativas y pautas de evaluación.

Vertical tests of a prototype half-wave resonator cavity are being tested. The performance of the cavities, such as quality factor and accelerating electrical field, are measured and compared to the target design value. In previous study, we reported the effect of the heat treatment on a prototype bare HWR cavity. We baked a jacketed HWR cavity to improve a performance for 10 h at 650°C. In this study, we will report the effect of the heat treatment on the jacketed HWR cavity., Proceedings of the 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany

A prototype of half-wave resonator (HWR) cryomodules is fabricated and tested. Cables and tray are installed for horizontal test. The design and the piping and instrumentation diagram (P&ID) of the HWR cryomodule are presented. The HWR cryomodule is tested with developed programmable logic controller (PLC) and experimental physics and industrial control system (EPICS) control systems. The heat loads of the HWR cryomodule for static and dynamic are measured., Proceedings of the 29\textsuperscript{th} Linear Accelerator Conf., LINAC2018, Beijing, China

Construction of the RAON heavy ion accelerator facility is in-progress in Korea. The driver linac is a superconducting linac with 200 MeV/u for uranium beam and 400 kW beam power. Prototyping of major components and their tests are proceeding including superconducting cavities, superconducting magnets and cryomodules. December 2016, the RFQ accelerated oxygen beam. Status report of the RAON accelerator systems is presented., Proceedings of the 18th Int. Conf. on RF Superconductivity, SRF2017, Lanzhou, China

Heat treatment, 650C for 10hrs, was carried out to improve the performance of a half-wave resonator cavity. In this presentation, we report how the heat treatment was performed. X-ray diffraction analysis and residual gas analysis were performed to investigate the effect of the heat treatment on the cavity performance., Proceedings of the 29\textsuperscript{th} Linear Accelerator Conf., LINAC2018, Beijing, China

A quarter-wave resonator (QWR) and a half-wave resonator (HWR) cryomodules and the control systems such as programmable logic controller (PLC) are developed. Temperature sensors such as Cernox-1050 are calibrated and applied to the cryomodules. Preparation of vertical test is introduced. QWR and HWR cryomodules are fabricated and tested by using the developed PLC control system. The PLC rack and temperature monitors are shown and the human machine interfaces (HMI) screen is shown when the HWR cryomodules is tested at 2 K., Proceedings of the 61\textsuperscript{st} ICFA ABDW on High-Intensity and High-Brightness Hadron Beams, HB2018, Daejeon, Korea

Quarter-wave resonator (QWR), half-wave resonator (HWR) and single-spoke resonator (SSR) cryomodules are used for RAON accelerator. The layout of RAON accelerator and three types of cryomodules such as QWR, HWR and SSR are shown in the linac. SRF test facility which consists of cryoplant, cleanroom, vertical test facility and horizontal test facility is constructed. Cleanroom has high pressure rinsing (HPR), ultrasonic cleaning (USC), buffered chemical polishing (BCP), high vacuum furnace and cavity assemble place. The test plan for cavity and cryomodules is presented., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

Residual resistance ratio (RRR) of 300-grade niobium has been analyzed to find optimal welding condition for a superconducting cavity. RRR values were not only measured along the welding directions, but also perpendicular to the welding lines. In this presentation, we will show the RRR analysis as a function of the distance, the welding speed, and the welding pressure., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

Quarter-wave resonator (QWR) cryomodule is developed for linac demonstraction. The plan and layout of the linac demonstration are shown. 3D drawing and P&ID are shown for the quarter-wave resonator (QWR) cryomodule. The QWR cryomodule consists of cavity, coupler, tuner, liquid helium reservoir, thermal shield and magnetic shield. PLC rack is fabricated to control the QWR cryomodules. The PLC controls and monitors pumps, heaters, cryogenic valves, solenoid valves, gate valves and temperature sensors., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA