1 Magnet field testing Kevin Tilley, Paul Flower, Mark Rayner, Henry Nebrensky, 16 th November Upstream magnets:- Dipole B1 Quadrupoles Q1-Q3 Downstream magnets:- Dipole B2 Quadrupoles Q4-Q9

2 2 Upstream dipole – B1 – completed tests Upstream dipole critical to extract beam from synchrotron vault. Performed functional tests prior to installation in July. Performed electrical/water tests (AN talk) Field map & L_effective as expected Central field versus current to 250Amps. Measurements agreed perfectly with tables & theory (Leff) to 250A. Not tested to full field.

3 3 Upstream dipole – B1 – future tests Polarity in situ Full B.v.I tests (into saturation) Determine rqd reproducibility (B/I) Measure hysteresis & complete standardisation if rqd. Scheduled for w/c 14 th Jan’08 Note, some discussion about changing pole tip of this magnet for non-tapered pole (homogeneities) – use same tests May monitor the field of this measurement directly during running if hysteresis significant.

4 4 Upstream quadrupole – Q1 – completed tests Performed functional tests prior to installation in July. Performed electrical/water tests (AN talk) Measured g.v.I, hysteresis Measured (g, magnetic centre, skew)

5 5 Upstream quadrupole – Q1 – completed tests Jig allows measurement of field relative to mechanical centre & known rotation – survey references. Sample field along 3 lines -> extract 4 parameters, then solve for (g,magnetic centre(x,y), skew). Errors in magnetic centre ~ ±0.1mm no significant magnetic centre displacement no significant skew. g.v. I as expected. hysteresis measured at ~0.5% - magnet works ok.

6 6 Upstream quadrupoles – Q1-Q3 –future tests Polarity in situ Scheduled for w/c 14 th Jan’08

7 7 Downstream dipole – B2 – future tests Polarity in situ Full B.v.I tests (into saturation) Determine rqd reproducibility (B/I) Measure hysteresis & complete standardisation if rqd. Scheduled for w/c 9 th Jan’08 or early December if services available.

8 8 Downstream quadrupoles – Q4-Q9 – present tests Perform basic tests.…to qualify as early as possible if any problems exist.… Pole tip fields to determine ~g.v.I Field balance on each pole tip / colloid. If indications, potential to perform detailed checks with jig. Expected to begin this week, turnaround time <1week per magnet.

9 9 Downstream quadrupoles – Q4-Q9 – present tests We have only incomplete field specifications for the Q35s! Detailed tests on at least two Q35s complete with mirror plates. Measure one magnet with each of the two coil types for reference data. L_effective. Adaptor & jig -> detailed (g,magnetic centre(x,y), skew) as before. g.v.I Determine required reproducibility. Hysteresis. Standardisation if required. In ~2-3weeks

10 Summary. Upstream magnets:- Dipole:- performs well to 250A. Checks of full current, polarity, hysteresis in situ. w/c Jan 14th Quadrupoles: one magnet tested – performs well. Polarity of all in situ. w/c Jan14th. Downstream magnets:- Dipole:- to be tested early December or w/c Jan 9 th. Quadrupoles: basic testing schedule commencing this week. Detailed measurements on at least two of differing coil types for reference data.