Akiba Group

Experimental Equipment

Low Temperature & High Magnetic Field

• Cryogen-free He3 Refrigerator (Niki Kogei)

  

  Achieves a base temperature of 300 mK without using liquid cryogens such as helium or nitrogen. A cryogen-free superconducting magnet capable of generating up to 9 T will be installed soon.

• Superconducting Magnet (Cryomagnetics, Inc.)

  

  Generates up to 9 T when cooled with liquid helium (up to 11 T when used with a lambda-point refrigerator). Temperature can be controlled from 1.5 K to 300 K using a variable temperature insert (VTI).

High Pressure

• Indenter-type Pressure Cell [T. C. Kobayashi et al., Rev. Sci. Instrum. 78, 023909 (2007)]

  

  Pressure is generated by pressing a tungsten carbide indenter into a NiCrAl alloy cavity filled with liquid medium. The standard sample space is about 1 mm in diameter, with a maximum pressure of approximately 4 GPa. Combined with a custom magnetic field rotation mechanism, it enables measurement of physical quantities' magnetic field directional dependence under pressure.

• Opposed Anvil Pressure Cell [K. Kitagawa et al., J. Phys. Soc. Jpn. 79, 024001 (2010)]

  

  Pressure is generated by compressing a metal gasket with a central hole filled with liquid medium between two tungsten carbide anvils. The standard sample space is about 2.5 mm in diameter, and the maximum pressure reaches about 10 GPa. This cell balances a relatively large sample space with high attainable pressure.

• Piston Cylinder Pressure Cell (C&T Factory)

  

  Pressure is applied by compressing a Teflon capsule filled and sealed with liquid medium. Cells with cylinder inner diameters of 4, 5, and 6 mm are available, with a maximum pressure of about 3 GPa. Allows a variety of measurements utilizing the wide sample space.

• Diamond Anvil Cell (HMD)

  

  Pressure is generated by compressing a metal gasket with a central hole filled with liquid or soft solid medium between two diamonds. Maximum pressure exceeds 10 GPa. We plan to set up and use this equipment for measurements in our lab in the near future.

Measurement Instruments

• AC Resistance Bridge (Model 372, Lake Shore Cryotronics)

• Temperature Controller (Model 335, Lake Shore Cryotronics)

• Digital Lock-in Amplifier (LI5650, NF Circuit Design Block)

• Low Noise Amplifier (SA-410F3, NF Circuit Design Block)

• Voltage-to-Current Converter Module (VI-309F1, NF Circuit Design Block)

• Low Noise DC Power Supply (LP5392, NF Circuit Design Block)

• DC Voltage/Current Source (TR6142, Advantest)

• Function Generator (DG4202, RIGOL)

• DC Stabilized Power Supply (PA600-0.1B, Texio Technology)

• Capacitance Bridge (2500A, Andeen-Hagerling, Inc.)

• Oscilloscope (4262, Pico Technology)

• Digital Multimeter (DMM6500, Keithley-Tektronix)

• Pre-amplifier (Analog Devices AD524, Homemade)

Numerical Computing

• AMD Ryzen™ 9 Cluster Computer (Homemade)

  

  A homemade cluster computer with a total of 64 cores assembled from commercial parts. Used for first-principles calculations (Quantum ESPRESSO) and other small- to medium-scale numerical computations.

Others

• Hydraulic Press (RIKEN Equipment)

  

  A hydraulic press capable of applying a maximum load of 200 kN (~20 tons). Used for pressurizing indenter, piston-cylinder, and opposed anvil pressure cells.

• Stereomicroscope (Evident)

  

  A stereomicroscope that can magnify samples up to 63 times. Used for detailed sample setup work. Real-time observation on PC screen, shape measurement, and image saving are possible via a USB digital camera.

• Drill Press (SK11) & Lathe (PROXXON)

  

  Tabletop machine tools capable of simple metal machining. Used for making pressure cell parts and custom measurement devices.

• 3D Printer (Bambu Lab)

  

  Used for manufacturing prototypes and resin parts.