What are neutrons?  And what do we have against them?

Posted by Rezwan on Jan 14, 2011 at 10:30 PM
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What gave you that idea?  We’re not neutron haters.  We just don’t want to produce any stray, rogue neutrons in a fusion reaction.

It’s not that neutrons are evil and we want to banish them all to the far reaches of the galaxy.  Neutrons are everywhere, adding mass to atoms (except hydrogen - a lone proton).  When neutrons sit there, bound up in a nucleus, we love them, couldn’t live without them.  Theyr’e a big part of us. 

And, when they’re being used to explore materials properties they are incredibly fascinating (see below). 

It’s those rogue neutrons we take issue with.  Yes, most neutrons are stable, law abiding citizens of a nucleus.  Well, OK, technically the “rogues” are also law (of physics) abiding.

The rogue neutrons fly around, unbound, unstoppable until they slam into the nucleus of some atom, either breaking it apart and causing chain reactions or leading to general instability of the new nucleus home (picture another neutron in the formerly stable nucleus now saying - “either he goes, or I go”).  In short, destabilization, chain reactions and radioactivity with a possibility of nuclear weapons material.

For those of you who don’t like the “neutron profiling” we’re doing, here is a broader perspective on neutrons.  Get in touch with them - opens up a world of materials science and particle physics.  Tons of fun!

History of Neutron Awareness

The neutron will be celebrating its 79th birthday this year.  James Chadwick won a Nobel Prize for identifying it in 1932.  Electrons and protons are a bit older:  JJ Thompson proposed the existence of electrons in 1898. 

ORNL Neutron source:
From Press Release, May 1, 2006.

One of the largest and most anticipated U.S. science construction projects of the past several decades has passed its most significant performance test. The Department of Energy’s Spallation Neutron Source, located at Oak Ridge National Laboratory, has generated its first neutrons.

Research conducted at the SNS will lay the groundwork for the next generation of materials research. Researchers think that the greatly improved ability to understand the structure of materials could lead to a virtually limitless number of innovations, including stronger and lighter airplanes, a new generation of batteries and fuel cells, and time-released drugs that target a specific body organ.  Just after 2 p.m. Friday, a pulse of protons from the SNS’s accelerator complex, traveling at nearly the speed of light, struck its mercury target. The protons “spalled” neutrons from the nuclei of mercury circulating inside the target. These first neutrons were recorded on equipment specially installed for the commissioning.

ORNL Home:  neutron sciences http://www.ornl.gov/ornlhome/neutron_science.shtml
http://neutrons.ornl.gov/facilities/SNS/ Spallation neutron source
http://neutrons.ornl.gov/facilities/SNS/works.shtml  How the spallation neutron source works.