• KAGRA
• KSC
• EducationTraining
• ResearchTopics

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)