= Possible research topics for graduate students and postdocs = <> == CRY (Cryogenics) related == === Thermal Noise === * Mechanical Q measurement (sapphire fiber, blade spring, bonding, coatings, ...) * Evaluation of sapphire suspension thermal noise * Evaluation of thermal noise of integrated cryo-payload * Design of new sapphire blade spring * Measurement of violin mode of sapphire suspension fibers and their subtraction from data === Cryogenics === * Development of high-sensitivity local displacement sensor at low temperature * Development of frosting removal on mirror by using CO2 laser or heater * Evaluation of low-magnetism black-coating (optical absorption at 1064nm ...) * Optical absorption measurement of the sapphire mirror at low temperature * Development of non-contact temperature measurement method of mirror == PEM (Physical Environment Monitoring) related == ===　Underground environment evaluation　=== * New environmental monitors * Seismometer analysis * Magnetometer analysis * Microphone analysis * Newtonian noise evaluation === Interferometer noise evaluation === * New environmental monitors * Power line monitor, GND survey * Correlation/coherent analysis (Close to commissioning) * Glitch, line noise evaluation (Close to DetChar) * Feedforward, offline noise subtraction * PEM injection test == VIS（Vibration Isolation System）related == ===　Sensor Development === * Development of new local sensor with high-sensitivity, wide-range, and cryogenic use, replaced from OSEM and photo-sensor * Development of new local sensor by using optical comb technology * Development of inertial sensor (seismometer, accelerometer) === Performance Improvement === * Optimization of control, development of active filter * Filter synthesis using modern methods, such as H2/H-infinity and mix-sensitivity methods [Terrence's suggestions]. * Control of low-frequency range by using GIF * Improvement of lower frequency performance of IP * Development of light and easy maintenance GAS filter * Seismic/sensor noise modeling and prediction. [Terrence's suggestions] * Towards Advanced Control Systems [Terrence's suggestions]: * Adaptive Seismometer feedforward/coupling-cancellation using adaptive LMS filters (Show that it works and somehow make it work in KAGRA). * Search for a potentially better control scheme (e.g. MPC, DMD with control, machine learning control, etc..), optimized it, and compare it to the current optimized control performance. * Major overhaul of the existing control interface so these control strategies are implementable. == CAL (Calibration) related == === DAC/CAL (Software) === * Timing correction * Line-noise subtraction * Optimization of avoidance method of dynamic range problem * Improvement of self-diagnosis of pipe-line * Improvement of interface of pipe-line, filter, injection and so on === Commissioning/CAL (Hardware) === * PCAL * Higher performance of calibration of integrating sphere (5% -> <1%) * Mitigation of scattered light(in O4) * Stabilization of Pcal laser * Correction of temperature dependence of integrating sphere * Evaluation of integrating sphere like injection angle of laser and opening size (in O5) * Development of Gcal == DMG (Data Management) related == * Operation of DMG * Development of data sharing way between low and high latency data * development of data base * GRID computing == IOO (Input & Output Optics) related == * R&D of Mach–Zehnder * Angular Sensing Control of Input Mode Cleaner * Redesign of IMMT TRANS breadboard * Intensity noise at IMC * Redesign of PSL optical path * Arrangement of cabling at around PSL and IMC * Improvement of ALS fiber noise canceling (FNC) * Improvement of ALS PLL == Laser related == === Evaluation and Introduction of High Power Laser === * Debug * Reduction of intensity noise * Built of EPICS control === New Technology Development === * Control by EPICS Learning == AOS (Auxiliary Optics) related == === stray-light mitigation === * Development and/or characterization of light-absorbing materials required for the large-scale interferometers * Stray-light mitigation in the actual KAGRA interferometer with ray-trace software simulation and their actual fabrication * Design, assembly, and evaluation of optical baffles and beam dumps for KAGRA, as well as the installation * Characterization of stray-light noises in KAGRA === TMS (Transmission monitor system) === * Characterization of the vibration-isolation stages TMS * Characterization of the optical setup of TMS == MIF (Main Interferometer) related == * RSE locking simulation and commissioning * Alignment sensing and controls simulation and commissioning * Laser frequency stabilization * Interferometer characterizations (optical parameters, mode content, birefringence, high power effect, etc.) * Parametric instability modeling and mitigation * Commissioning and upgrade of transmission monitor system (TMS-VIS, optical table cover, polarization monitor) * Output optics development (OMC, beam shutter, etc.) * In-vacuum RF PD and RF QPD development * Upgrade of Mach-Zehnder modulator == DGS (Digital System) related == === Timing synchronization === * Evaluation of accuracy and precision of received GPS (including automation) * Evaluation of accuracy of ADC/DAC synchronization for OMC, ETMX, and ETMY. * Measurement of timing delay === Other === * Interferometer diagnosis system == DetChar (Detector Characterization) related == === Glitch noise investigation === * Searching auxiliary channels which have many coincidence events with main interferometer signals * Glitch classification from glitch waveform (providing glitch catalogue) * Rejecting fake gravitational wave events by information of glitches on auxiliary channels * h(t) generation and comparison before and after glitch rejection === Narrowband noise (spectral lines) === * Automation of line identification (freq, Q, etc) and constructing line data base * Automation of calibration line removal and evaluation of robustness of removal method. * Know lines (such as reference signal) removal === Computing === * Constructing the system which receives GW alerts from GraceDB * Automation of launching glitch pipelines by using GW alerts * Construction database of known/unknown spectral lines === Others === * Evaluation of background noise of auxiliary channels, especially for environmental sensors * Searching safe channel (which is not affected by GWs) and evaluation coherence between safe channel and h(t) * Software noise removal by using safe channels == GIF(Geophysics Interferometer) == === Subjects on GIF observation data === * Origin of acoustic strain vibrations associated with felt earthquakes * Response of underground strains to rainfall and air pressure * Relations between earthquakes in the fault and strain changes * Relations between volcanic/seismic activities and regional strains === Subjects related to development of instruments === * Background noise of GIF and its improvement * Stable operation of KAGRA using strainmeter/seismometer data == Mirror related == * Q measurement of coating at cryogenic temperature * absorption measurement of sapphire bulks * absorption measurement of crystalline coatings * birefringence measurement of sapphire bulks * impact of birefringence in IFO (simulation) == AEL (Analogue Electronics) == == FCL (Facility) == == VAC (Vaccum) ==