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I heard about this on the radio and was surprised I hadn't heard of Atomic Gardening before. Basically, farmers and gardeners would expose large quantities of s

I heard about this on the radio and was surprised I hadn't heard of Atomic Gardening before. Basically, farmers and gardeners would expose large quantities of seeds and plants to varying degrees of radiation, and look for useful mutations. Rio Red grapefruits, accounting for 3/4 of Texan-produced grapefruit, were originally created by Atomic Gardening! From the Grapefruit wiki, which links to the Atomic Gardening one : "Using radiation to trigger mutations, new varieties were developed to retain the red tones that typically faded to pink. The 'Rio Red' variety is a 2007 Texas grapefruit with registered trademarks Rio Star and Ruby-Sweet, also sometimes promoted as Reddest and Texas Choice. The 'Rio Red' is a mutation-bred variety that was developed by treatment of bud sticks with thermal neutrons. Its improved attributes of mutant variety are fruit and juice color, deeper red, and wide adaptation.[21]" [20] https://www.nytimes.com/2007/08/28/science/28crop.html?_r=1&pagewanted=print&oref=slogin https://www.nytimes.com/2007/08/28/science/28crop.html?_r=1&... [21] https://mvd.iaea.org/ https://mvd.iaea.org/

superkuh 5y ago
The Rio red variety was not developed in 2007. It was developed in the 1980s, in, you guessed it: Rio, Brazil. When I first heard about this some handful of years ago I was naturally curious about how a researcher in Rio in the 1980s had access to thermal neutrons without a fission reactor. After a lot of reference digging and discussion on physics forums we came to the conclusion it was most likely a penning trap style fusor with some thick moderator. The Mars Curiosity rover also had/has a penning style trap for generating neutrons to probe for underground water sources.
- pfdietz 5y ago
  What makes you think "Penning Trap"? Neutron generator tubes have been used since forever in the oil well logging industry. They use an electric field to accelerate deuterium ions into a solid target containing deuterium or tritium. As far as I know, fusors have never been commercially successful as neutron generators. Also, why would one use neutrons for plant mutagenesis? Photons are far easier to make. An x-ray tube will produce a given (biologically effective) dose at a very small fraction of the cost of a neutron generator.
- pfdietz 5y ago
  The Curiosity neutron source is indeed a conventional pulsed sealed-tube neutron source, not a Penning trap. https://www.researchgate.net/publication/5253560_The_Dynamic_Albedo_of_Neutrons_DAN_experiment_for_NASA's_2009_Mars_Science_Laboratory https://www.researchgate.net/publication/5253560_The_Dynamic...
  - superkuh 5y ago
    Sorry I wasn't clear. The DAN and other pulsed sealed tube neutron sources use a penning trap for their ion sources. But yeah, it was an incomplete and inaccurate wording.

superkuh 5y ago

The Rio red variety was not developed in 2007. It was developed in the 1980s, in, you guessed it: Rio, Brazil. When I first heard about this some handful of years ago I was naturally curious about how a researcher in Rio in the 1980s had access to thermal neutrons without a fission reactor. After a lot of reference digging and discussion on physics forums we came to the conclusion it was most likely a penning trap style fusor with some thick moderator. The Mars Curiosity rover also had/has a penning style trap for generating neutrons to probe for underground water sources.

pfdietz 5y ago
What makes you think "Penning Trap"? Neutron generator tubes have been used since forever in the oil well logging industry. They use an electric field to accelerate deuterium ions into a solid target containing deuterium or tritium. As far as I know, fusors have never been commercially successful as neutron generators. Also, why would one use neutrons for plant mutagenesis? Photons are far easier to make. An x-ray tube will produce a given (biologically effective) dose at a very small fraction of the cost of a neutron generator.
pfdietz 5y ago
The Curiosity neutron source is indeed a conventional pulsed sealed-tube neutron source, not a Penning trap. https://www.researchgate.net/publication/5253560_The_Dynamic_Albedo_of_Neutrons_DAN_experiment_for_NASA's_2009_Mars_Science_Laboratory https://www.researchgate.net/publication/5253560_The_Dynamic...
- superkuh 5y ago
  Sorry I wasn't clear. The DAN and other pulsed sealed tube neutron sources use a penning trap for their ion sources. But yeah, it was an incomplete and inaccurate wording.