Continuous Versus Average Cross Section
Cross sections depend strongly on the incoming particle speed. In the case of a beam with multiple particle speeds, the reaction rate R is integrated over the whole range of energy:
Where σ(E) is the continuous cross section, Φ(E) the differential flux and N the target atom density.
In order to obtain a formulation equivalent to the mono energetic case, an average cross section is defined:
Where Φ= Φ(E) dE is the integral flux.
Using the definition of the integral flux Φ and the average cross section σ, the same formulation as before is found:
Read more about this topic: Neutron Cross Section
Famous quotes containing the words continuous, average, cross and/or section:
“The problem, thus, is not whether or not women are to combine marriage and motherhood with work or career but how they are to do so—concomitantly in a two-role continuous pattern or sequentially in a pattern involving job or career discontinuities.”
—Jessie Bernard (20th century)
“Today everything is different. I can’t even get decent food. Right after I got here I ordered some spaghetti with marinara sauce and I got egg noodles and catsup. I’m an average nobody, I get to live the rest of my life like a schnook.”
—Nicholas Pileggi, U.S. screenwriter, and Martin Scorsese. Henry Hill (Ray Liotta)
“You might say that Lyndon Johnson is a cross between a Baptist preacher and a cowboy.”
—Lyndon Baines Johnson (1908–1973)
“To look at the cross-section of any plan of a big city is to look at something like the section of a fibrous tumor.”
—Frank Lloyd Wright (1869–1959)