Questions About Quartz Infrared Heating Lamps Used in high-vacuum environments (P<1×10⁻⁵ Pa)

Original Questions about Quartz Infrared Heating Lamps Used in high-vacuum environments (P<1×10⁻⁵ Pa) :

1. Arc prevention with voltage ≤220V (preferably 110V).
2. Wire selection: Fiberglass-insulated wires vs. bare nickel wires with high-frequency ceramic standoffs?
3. Can gold-plated or ceramic reflective coatings be applied? Risks of coating volatilization/peeling causing arcing or other issues at 500°C?
4. For a 1m heating lamp, should cold-end length be 50mm or 200mm? Advantages of 200mm? Will it reduce sealing part temperature?
5. Connector recommendations for easy wiring and tube replacement.

Answer 1. Arc Prevention & Voltage Selection (220V vs. 110V)

Critical Issue: Minimal gas molecules in high vacuum elevate breakdown voltage, but field emission (micro-arcing) may occur due to small electrode gaps or surface contamination.

Solution: Prefer 110V operation; Maintain ≥10mm gap between cold-end wires.

Answer 2. Wire Selection: Insulated vs. Bare Wires with Ceramic Standoffs

Answer 3. Reflective Coating Risks (Gold vs. Ceramic)

Gold coating: Gold coating: There are Volatilizes at 500°C after a long time, contaminating vacuum and depositing on electrodes may cause short-circuit arcing.

Ceramic coating: Ceramic coating can resist high temperature more than 500℃, but it is still have a risk if coating fall off after a long working time.

Alternatives: No coating for quartz infrared lamps

Integrated quartz reflector: Installing high temperature resist reflect mirror

Answer 4. Cold-End Length Selection (50mm vs. 200mm)

In order to make lamps working longer time, the pinch sealing temperature should be ≤300°C .

Simulation Results for reference only:

Advantages of 200mm cold ending:

Lowers temperature to safe range (<300°C).

Reduces quartz cracking from thermal stress.

Enhancement: Add water cooling system around pinch sealing part

Answer 5. Connector Recommendations

Requirements: Vacuum-compatible, high-temp resistant, low contact resistance, quick-disconnect.

Solution:

Type: Metal-sealed quick-disconnect connectors (e.g., CF flange derivative).

Materials: Oxygen-free copper contacts + 304 stainless steel housing.

Insulation: Al₂O₃ ceramic spacers.

Summary of Recommendations