Thermal Gas Crackers

The TC series of thermal gas crackers rely on our successful electron beam heating technology. These instruments allow a very high dissociation efficiency of the molecular gas at low power. Furthermore, direct water cooling ensures that only the filament and the cracking tube are ever above 30oC, thus allowing extremely clean operation and no contamination.

Competitors thermal crackers employ a very hot (~2500oC) tungsten filament at high power (~400W), thus imposing an undesirable heat load on UHV systems. Also, those types of cracker are not very gas-efficient and of limited application (principally for H2) since tungsten is attacked by some gases, such as oxygen.

The Oxford Applied Research thermal gas crackers, models TC50 and TC4x50, exploit our established reactive gas-resistant e-beam heating technology. They incorporate fine bore inert cracker tubes which are connected directly to the gas lines, thus confining and minimising gas load, whilst providing a large surface area and long path length for high efficiency cracking at very low flow rates.

The catalytic nature of the cracker tube lowers the otherwise high temperature and power necessary to achieve substantial dissociation (>70%) at 60W. Also in contrast to tungsten filament crackers, they can be used to dissociate O₂, Cl₂ and other reactive gases. The graph above shows the dissociation of O₂, resulting in a decrease in the partial pressure of O₂ when the power to the cracker tube is applied at 10s The crackers are directly water cooled, which minimises outgassing, and are fitted with  a back-up electron emitter for prolonged operations. The TC50 contains a single cracker tube. The TC4x50 contains four cracker tubes with separate gas inlets thus allowing simultaneous dissociation of up to four gases.

Specifications

Brochure

Application Note

Radical Reactions with Organic Thin Film: Chemical Inte

• High dissociation efficiency
• Ultra-clean
• Low power
• Low Maintenance
• Back-up filament