# Fusion energy - Stage 4 (technology)

internal name `fusion-mk04` · tier 9 (Utility science pack, [tier 9](https://factorio.kalzumeus.com/tier/9.md))
HTML page: https://factorio.kalzumeus.com/tech/fusion-mk04/

## Cost

3600 units of (1 × [Utility science pack](https://factorio.kalzumeus.com/item/utility-science-pack.md), 2 × [pY science pack 4](https://factorio.kalzumeus.com/item/py-science-pack-4.md), 3 × [Production science pack](https://factorio.kalzumeus.com/item/production-science-pack.md), 6 × [pY science pack 3](https://factorio.kalzumeus.com/item/py-science-pack-3.md), 10 × [Chemical science pack](https://factorio.kalzumeus.com/item/chemical-science-pack.md), 20 × [pY science pack 2](https://factorio.kalzumeus.com/item/py-science-pack-2.md), 30 × [Logistic science pack](https://factorio.kalzumeus.com/item/logistic-science-pack.md), 60 × [pY science pack 1](https://factorio.kalzumeus.com/item/py-science-pack-1.md), 100 × [Automation science pack](https://factorio.kalzumeus.com/item/automation-science-pack.md), 20 × [Military science pack](https://factorio.kalzumeus.com/item/military-science-pack.md)), 600 s each.

## Requires (2)

- [Fusion energy - Stage 3](https://factorio.kalzumeus.com/tech/fusion-mk03.md)
- [Nucleosynthesis 3](https://factorio.kalzumeus.com/tech/nucleo-mk03.md)

## Leads to (0)

- none

## Unlocks (1 recipes)

### Fuse boron with a proton (`b-h`)

- 40 s · tier 9
- Ingredients: 20 × [Hydrogen proton](https://factorio.kalzumeus.com/fluid/proton.md), 20 × [Boron](https://factorio.kalzumeus.com/item/boron.md), 10 × [Liquid helium](https://factorio.kalzumeus.com/fluid/liquid-helium.md)
- Results: 10000 × [Neutron](https://factorio.kalzumeus.com/fluid/neutron.md) (4000°C), 160 × [Helium](https://factorio.kalzumeus.com/fluid/helium.md)
- Made in: Aneutronic fusion reactor
- Unlocked by: [Fusion energy - Stage 4](https://factorio.kalzumeus.com/tech/fusion-mk04.md)