The researchers also found that single atoms of metal could transmit up to 100 microamperes of current. The extracted beam current is 400 microamperes and can be extracted simultaneously in any split ratio from two extraction ports on opposite sides of the cyclotron. While earlier systems required about 500 microamperes at five volts now it is less than 100 microamperes.
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about 4,047 square metres (0.405 hectares) (see below). While all modern variants of the acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends on which yard it is based.
There are 43,560 square feet in an acre. An acre is also equal to 4046.86 square meters or 4840 square yards. If you want to convert any unit of area to other you can use these : Land Area Calculator.