Circulation cryostat DXNCMD

Description
The DXNCMD microscope continuous-flow cryostat is a continuous-flow refrigerant cooling system designed for integration with microscopes and spectrometers. It provides a two-stage cooling platform (sample stage and radiation shield), precise temperature control via a dedicated controller, and vacuum sample environment to prevent condensation and frost.

Features

• Designed for use under a microscope; top optical window standard, optional bottom window for transmission measurements (1 or 2 windows).
• Cooled with liquid nitrogen (LN2) or liquid helium (LHe); optional closed-cycle LHe configuration available.
• Multiple cryogenic electrical feedthrough options: oxygen-free copper enameled wire, low-thermal-conductivity phosphor bronze wire, cryogenic coaxial and triaxial cables.
• Maximum standard sample size: 20 × 20 mm (larger samples on request); adjustable sample distance for high-magnification objectives.
• Optional pressure-reduction device for LN2 to reach ~65 K minimum; optional sample holders and accessory modules (electrical, optical, magnetic, superconducting magnet, high-stage, 3D displacement).
• Automated temperature control with high stability and minimal vibration; low refrigerant consumption and fast cool-down.

Structure
Refrigerant is supplied from a self-pressurizing cryogenic storage tank through a supply tube into the cryostat where it vaporizes to provide cooling; exhaust gas is expelled via an outlet. The first cooling stage cools the sample stage while the second cools the surrounding radiation shield to improve temperature uniformity. A temperature sensor and heater are mounted on the sample stage; the sample chamber is evacuated to avoid condensation and frost during cooling and temperature regulation.

Parameters

• General temperature ranges: 80 K–500 K (LN2) and 6 K–500 K (LHe).
• DXNCMD model range: 3.2 K–325 K (expandable to 500 K for specific configurations).
• Typical cool-down times: room temperature to 78 K ≈ 45 min (LN2); room temperature to 5 K ≈ 90 min (LHe). Model-specific: DXNCMD ~20 min (fast cool-down option).
• Heating time to room temperature: < 40 min (LHe), < 20 min (LN2).
• Temperature stability: ≈ 50 mK (with LH101C controller).
• Interlayer vacuum: < 10⁻⁵ Pa; typical evacuation time ≈ 30 min (depends on pump).
• Windows: 1 or 2 fused silica windows, 20 mm diameter.
• Vacuum port interface: KF25. Temperature control interface: 6-pin vacuum connector.
• Cryogenic tank volumes: 10 L, 30 L, 50 L (standard), 100 L.
• Vibration amplitude: ≈ 20 nm; drift (1 h): ±1–150 nm (DXNCMD specification).
• Liquid helium consumption (approx.): ≈ 0.7 L/h at 5 K (DXNCMD).
• Weight (DXNCMD): ≈ 3.2 kg.

Technical specifications

• Model: DXNCMD.
• Temperature control (typical): LN2 80 K–500 K; LHe 6 K–500 K; DXNCMD 3.2 K–325 K (expandable to 500 K).
• Cooling performance: fast cool-down options (model-specific ≈ 20 min); general LN2/LHe cool-down as above.
• Temperature stability: ≈ 50 mK.
• Vacuum performance: interlayer vacuum < 10⁻⁵ Pa; evacuation time ≈ 30 min.
• Optical access: 1 or 2 fused silica windows, Ø 20 mm; top window standard, optional bottom window for transmission.
• Electrical interfaces: multiple cryogenic cable options; 6-pin vacuum connector for temperature control.
• Mechanical: compact design; optical cryostat family thickness < 50 mm (excluding stand) for DXNCMC/DXNCMD; weight ≈ 3.2 kg (DXNCMD).
• Vibration/drift: vibration ≈ 20 nm; drift (1 h) ±1–150 nm.
• Cryogen consumption and tanks: LHe ≈ 0.7 L/h at 5 K; tank volumes 10 / 30 / 50 / 100 L.
• Sample capacity: up to 20 × 20 mm (larger on request).