SLAC MEMORANDUM 	September 19, 2005

To:		Zach Wolf
cc:		Carl Rago, Roger Carr
From:		Paul Emma
Subject:		Everson-Tesla (‘ET’) Quadrupole Magnetic Measurements for LCLS

This note describes magnetic measurements to be performed on the first ‘ET’ quadrupole magnet.  I would like to measure the length-integrated gradient, Gdl, over several current settings, exploring the up and down cycles as well as small adjustments around these cycles.  Please perform the following measurements:

1)	Connect the magnet to a 10-A power supply.

2)	Run the magnet up to 5 A for ~30 minutes to warm it up.

3)	Standardize the magnet through ~3 cycles from 0 to 10 A, finally ending at zero (use a linear ramp rate of 2 A/sec and flat top pause of 5 sec).

4)	Measure Gdl from 0 to 10 A in 0.5-A steps (21 ‘up’ measurements).

5)	Measure Gdl back down, from 10 A to 0 in 0.5-A steps (21 ‘down’ measurements).

6)	Starting from the end of the last step (maintaining the history of the previous steps), measure Gdl at the following currents and in the indicated order:
[5.0 A,  5.5 A,  6.0 A,  5.5 A,  5.0 A,  4.5 A,  4.0 A]