←back to thread

New records on Wendelstein 7-X

(www.iter.org)
243 points greesil | 2 comments | 21 Jul 25 15:18 UTC | HN request time: 0s | source
Show context
bradleyy ◴[21 Jul 25 15:50 UTC] No.44636650[source]▶
In any future fusion power plant, a plasma with a high triple product must be maintained for long periods.

I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"

replies(5): >>44636712 #>>44636920 #>>44637043 #>>44637170 #>>44637243 #
dmbche ◴[21 Jul 25 15:55 UTC] No.44636712[source]▶
I believe it's "for as long as the reactor is to be operating", and they contrast that with the previous longest times being less than 45 seconds.
replies(1): >>44637497 #
Analemma_ ◴[21 Jul 25 16:59 UTC] No.44637497[source]▶
I thought the expectation was that actually-operating fusion plants would operate in pulses rather than continuously, but I could be misremembering.
replies(1): >>44637640 #
smallerize ◴[21 Jul 25 17:09 UTC] No.44637640[source]▶
Toroidal reactors have to operate in pulses. Stellarators can be operated in steady-state (although sometimes they are pulsed to achieve higher energy).
replies(2): >>44638284 #>>44640468 #
riffraff ◴[21 Jul 25 17:57 UTC] No.44638284{3}[source]▶
But don't you need to "refuel" now and then?
replies(2): >>44638515 #>>44640722 #
1. tetha ◴[21 Jul 25 18:16 UTC] No.44638515{4}[source]▶
W7x has a pellet injection system now.

This is shared in the better article here: https://www.ipp.mpg.de/5532945/w7x

> During the record-setting experiment, about 90 frozen hydrogen pellets, each about a millimeter in size, were injected over 43 seconds, while powerful microwaves simultaneously heated the plasma. Precise coordination between heating and pellet injection was crucial to achieve the optimal balance between heating power and fuel supply.

replies(1): >>44659956 #
2. riffraff ◴[23 Jul 25 14:58 UTC] No.44659956[source]▶
Neat, thanks