In topology, long time ago, I was taught that these are indeed 'intersection curves of surfaces of the second order'. Emphasis on surface being second order, not the curve. This was in Russian, which means that the English terms may be different. You might also encounter 'intersection curves of quadric surfaces'. There are seventeen types of quadric surfaces (including real and imaginary ones) and they're a right pain in the neck to calculate intersections of.
Artem > Dear All - > > if memory serves me right, the intersection curve of > a cone with a cylinder (like in a powder diffraction camera) is > not an ellipse, but a "Schnittfigur zweiter Ordnung", > loosly translated as 'intersection curve of second order'. > > Is there a correct English term for that type of curve? > > Thx, br > ----------------------------------------------------------------- > Bernhard Rupp > 001 (925) 209-7429 > +43 (676) 571-0536 > [EMAIL PROTECTED] > [EMAIL PROTECTED] > http://www.ruppweb.org/ > ----------------------------------------------------------------- > The hard part about playing chicken > is to know when to flinch > ----------------------------------------------------------------- >