{"id":3712,"date":"2026-02-02T11:30:13","date_gmt":"2026-02-02T02:30:13","guid":{"rendered":"http:\/\/kyotofusioneering.com\/kfwp\/?post_type=news&p=3712"},"modified":"2026-04-13T23:02:48","modified_gmt":"2026-04-13T14:02:48","slug":"the-fusion-era-fusion-101-vacuum-is-essential-for-fusion","status":"publish","type":"news","link":"https:\/\/kyotofusioneering.com\/en\/news\/2026\/02\/02\/3712","title":{"rendered":"THE FUSION ERA \u2013 Fusion 101 \/ Vacuum is Essential for Fusion"},"content":{"rendered":"\n
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In December last year, we attended a vacuum engineering conference in Tokyo, which brought together companies and organizations involved in innovating vacuum technologies. <\/p>\n\n\n\n

Kyoto Fusioneering (KF) also exhibited, and our CEO Satoshi Konishi gave a presentation highlighting the deep connection between vacuum technologies and fusion energy.<\/p>\n\n\n\n

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Let\u2019s start with the basics\u2014 \u201cWhat exactly is a vacuum?\u201d<\/em>\u2014and then learn why vacuum technologies are critical for fusion, the role of vacuum pumps, and KF\u2019s ongoing collaborative development efforts with Japanese manufacturing companies to bring world-class vacuum pumps to the fusion market.<\/p>\n\n\n\n

What Exactly is a Vacuum?<\/strong><\/h3>\n\n\n\n

When you hear the word \u201cvacuum,\u201d you might imagine a space completely devoid of air, like a vacuum-sealed food package. But that\u2019s not quite accurate.<\/p>\n\n\n\n

According to the Japanese Industrial Standards (JIS), a vacuum<\/em> is defined as \u201ca space filled with gas at a pressure lower than atmospheric pressure.\u201d <\/em>This means that even if some air or gas remains in a chamber, as long as the pressure is reduced below atmospheric levels using pumps or other equipment, it can be called a vacuum.<\/p>\n\n\n\n

Furthermore, vacuum conditions are categorized by pressure levels: \u201clow vacuum\u201d and \u201chigh vacuum\u201d, etc.<\/p>\n\n\n\n

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Illustration of air being drawn out of a bag to create a vacuum. Even the middle bag qualifies as a vacuum<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

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Vacuum in Everyday Life<\/strong><\/h3>\n\n\n\n

Vacuum exists around us more frequently than you might think.<\/p>\n\n\n\n

Food preservation<\/strong>
Coffee beans are often packaged in a vacuum, by removing air from the bag. Reducing oxygen exposure prevents oxidation of coffee beans, which helps to maintain aroma and flavor.<\/p>\n\n\n\n

Insulated bottles<\/strong>
A thermos or vacuum flask maintains the temperature of its contents by creating a vacuum layer between the inner and outer walls. In this vacuum layer, heat transfer via air is reduced, helping hot drinks stay hot and cold drinks stay cold.<\/p>\n\n\n\n

Straws<\/strong>
Even drinking through a straw relies on vacuum principles. When you suck the air out and lower the air pressure inside the straw, the difference between internal and external pressure pushes the liquid upward.<\/p>\n\n\n\n

Vacuum in Fusion<\/strong><\/h3>\n\n\n\n

Fusion power plants are sometimes described as \u201clarge, complex vacuum systems.\u201d<\/em> Vacuum technology is essential for fusion\u2014but why?<\/p>\n\n\n\n

There are two main reasons:<\/p>\n\n\n\n

Reason 1. Creating the environment required for fusion reactions to occur<\/strong>
To make fusion possible, hydrogen isotopes (deuterium and tritium) must be heated to hundreds of millions of degrees Celsius until they become plasma\u2014the fourth state of matter, where atoms split into electrons and nuclei and create a soup of electrically charged particles that move freely. <\/p>\n\n\n\n

But plasma cannot exist in ordinary air. Molecules of air (nitrogen, oxygen, and water vapor) would collide with and cool the plasma instantly, contaminate the fuel, and prevent the particles from reaching the temperatures and energies required for fusion. <\/p>\n\n\n\n

For this reason, the inside of a fusion reactor core must be almost completely emptied of air before the fuel is injected and heated.<\/p>\n\n\n\n

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\u00a0Illustration of the four states of matter.<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

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The presence of vacuum is especially important in magnetic confinement fusion\u2014where magnetic fields generated by powerful magnets are used to confine plasma and force fuel particles to collide.<\/p>\n\n\n\n

Because of this, vacuum pumps that create and sustain the required vacuum environment are indispensable devices for enabling fusion reactions.
(For more on confinement methods, please refer to another Fusion 101<\/em> blog post here<\/a>.)<\/p>\n\n\n\n

2. Circulating Fuel Efficiently and Continuously<\/strong>
Fusion plants require a fusion fuel cycle system to clean and recycle unreacted hydrogen isotopes as the fuel. In a fusion fuel cycle, plasma that is cooled to gas containing unused fuel is collected, impurities like oxygen and nitrogen removed, and the purified fuel is fed back into the fusion reactor\u00a0core.<\/p>\n\n\n\n

Furthermore, movement of hydrogen isotopes (tritium and deuterium) must be carefully and efficiently controlled because hydrogen, the lightest element, can permeate into many materials. Importantly, tritium, being radioactive, must be prevented from leaking for safety. <\/p>\n\n\n\n

Operating the fuel cycle under vacuum ensures that hydrogen can flow smoothly through the system, prevents leaks and contamination, and allows the fuel to be continuously purified and returned to the reactor with high efficiency.<\/a><\/p>\n\n\n\n

What Makes Vacuum Pumps for Fusion Special?<\/strong><\/h3>\n\n\n\n

Vacuum pumps used in fusion plants must meet several demanding requirements.<\/p>\n\n\n\n

1. Tritium compatibility<\/strong>
Tritium reacts with organic materials like rubber or resins, causing these materials to degrade over prolonged exposure to tritium.
Therefore, fusion pumps must be:<\/p>\n\n\n\n