# hot cathode

> type of electrode.

**Wikidata**: [Q1365473](https://www.wikidata.org/wiki/Q1365473)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Hot_cathode)  
**Source**: https://4ort.xyz/entity/hot-cathode

## Summary
A hot cathode is a type of electrode that emits electrons when heated, serving as an essential component in vacuum tubes and gas-discharge lamps. It belongs to the broader class of cathodes, which are electrodes from which conventional current exits an electrical device.

## Key Facts
- **Aliases**: 热阴极, 熱陰極
- **Part of**: vacuum tube, gas-discharge lamp
- **Subclass of**: cathode
- **Freebase ID**: /m/08b2vt
- **Encyclopedia of China ID**: 124969
- **Microsoft Academic ID (discontinued)**: 47645306
- **Wikipedia languages**: de, en, fa, fr, id, ko, nn, pl, pt (9 languages total)
- **Site link count**: 9 (hot cathode); 70 (parent cathode class)
- **Store ID (Google Play)**: glødekatode

## FAQs
### Q: What is a hot cathode?
A: A hot cathode is a type of electrode designed to emit electrons through heating, commonly used in vacuum tubes and gas-discharge lamps.

### Q: How does a hot cathode differ from a cold cathode?
A: The source does not provide comparative details between hot and cold cathodes; hot cathodes are explicitly defined as electrodes within cathode subclass and devices like vacuum tubes.

### Q: In which devices are hot cathodes typically found?
A: They are integral components of vacuum tubes and gas-discharge lamps, as specified in their "part_of" classification.

### Q: What identifiers exist for hot cathode?
A: It has Freebase ID /m/08b2vt, Microsoft Academic ID 47645306, and Encyclopedia of China ID 124969.

## Why It Matters
Hot cathodes enable the operation of foundational electronic devices like vacuum tubes and gas-discharge lamps by providing a controllable source of electron emission. Their role in these technologies has historically supported telecommunications, lighting, and early computing systems. By facilitating electron flow through heating, they solved the challenge of initiating and sustaining electrical discharges in sealed environments, making them pivotal for mid-20th century electronics despite obsolescence in many applications.

## Notable For
- **Exclusive use in high-emission devices**: Exclusively applied in vacuum tubes and gas-discharge lamps where heated electron emission is required.
- **Cross-linguistic recognition**: Features in 9 Wikipedia language editions, including major languages like English, German, French, and Korean.
- **Academic classification**: Explicitly categorized as a subclass of cathode, distinguishing it by function in electrical devices.
- **Historical documentation**: Included in the Encyclopedia of China (Third Edition) under ID 124969, reflecting its technical significance.

## Body
### Definition
A hot cathode is a type of electrode that emits electrons when heated. It belongs to the cathode class, defined as an electrode from which conventional current exits a polarized electrical device.

### Applications
- Part of vacuum tubes
- Component in gas-discharge lamps

### Identifiers
- **Freebase ID**: /m/08b2vt (referenced from Wikidata item Q15241312, published October 28, 2013)
- **Microsoft Academic ID**: 47645306 (discontinued)
- **Encyclopedia of China ID**: 124969 (Third Edition)

### Language Presence
Wikipedia articles exist in 9 languages: de, en, fa, fr, id, ko, nn, pl, pt.

### Related Entities
- Parent class: cathode (70 site links)
- Aliases: 热阴极, 熱陰極  
- Google Play store ID: glødekatode

## References

1. Freebase Data Dumps. 2013
2. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)