Beta-plus (Î² +) radiation is the emission of positrons, which are the antimatter form of electrons. When a positron slows to speeds similar to those of electrons in the material, the positron will annihilate an electron, releasing two gamma photons of 511 keV in the process.
The Congressional Budget Office puts the cut-off lower, at $347,000 in 2007, or $252,000 after subtracting federal taxes and adding back transfers. Measured by net worth, rather than income, the top 1% started at $6.9m in 2009, according to the Federal Reserve, down 23% from 2007.
A look at the big picture. The latest numbers from the IRSâbased data from 2013 tax returnsâshow what it takes to be among the top 1% of income earners: At least $428,713 of adjusted gross income. Thatâs about $6,000 less than it took to buy into this rarified status a year earlier.