# Mark's Sandbox

random text forming a paragraph

Suggested coordinate system for linear detector elements in a plane perpendicular to z.

Assume line direction is chosen to go in the positive $y$ direction. If the line is parallel to the x-axis, choose the positive direction to be the positive x direction. Then the angle of inclination of the line is an angle $\phi$, 0 <= phi < 180. The unit vector along the line is lhat = xhat cos phi + yhat sin phi, the unit vector normal to the line (in the detector plane) is nhat = -xhat sin phi + yhat cos phi. In this way, lhat and nhat satisfy the right hand rule, i. e., lhat cross nhat = zhat.

- here are some new bullets
- as a test

<img src="https://halldweb.jlab.org/wiki/images/5/5b/D00000-01-01-2000.png">

here is an edit

--marki 17:23, 6 October 2014 (EDT)