Phobos Magnet Status

1
Phobos Magnet Status

• Leslie Rosenberg Patrick Decowski, MIT
• Technical Advisory Committee
• November 1998

2
Magnet Design

• Phobos Magnet is
• Double dipole
• Resistive coils
• 2 Tesla in spectrometer
• Low Field outside of spectrometer

100 MeV/c
1 GeV/c
3
The Phobos Magnet _at_ Danfysik
4
Manifolding
5
More Manifolding
6
Coils
7
Factory Acceptance Tests

• Factory Acceptance tests were conducted on Oct 1
  2 _at_ Danfysik
• Voltage drop, Pressure drop, Temperature rise
  were measured. All according to Specs
• At 1/7 of the nominal magnet current
• B 0.4 T in center
• Field is uniform, no surprises
• No measurable deflection at this reduced current
  setting.

Magnet passed Factory Acceptance tests!
8
Magnet Arrival _at_ BNL
9
Safety Review

• The Phobos Magnet was reviewed by the Safety
  Commitee in Feb. 98
• Some action items arose, a response to the action
  items was submitted to the Safety Committee
• We are working with J. Scaduto to generate
  procedures for operating the magnet. These will
  be refined while the magnet is at the AGS
• Magnet Stand was designed
• Seismic tie-down (action item from the safety
  review)
• 3-axis adjustment

10
Magnet Stand Design
Top View
Horizontal Movers
Side View
Vertical Adjustment
Bolts screw into bolt holes in yoke
Tie-down to the tunnel floor
11
Field Mapping
Determining number of points for field map
By field in y0 plane
Max. absolute By gradient
12
Field Mapping II
By field weighted by the gradient

• Strategy
• measure one arm in detail, other in a few points,
  use symmetry
• 45 deg trajectories
• 3cm spacing between trajectories (40
  trajectories)
• B measurement every 1cm along trajectory
• 3cm vertical spacing (5 planes in gap)
• 1 trajectory 1/2 hrs

Trajectories of probe
40x5x0.5 100hrs for one current setting
13
Schedule

• Nov 3 Magnet arrives _at_ BNL
• Nov 3 - Dec 2 Commissioning of magnet _at_ AGS
• Assembly of components
• Interlock sensors
• Manifolding Buss-bars
• B-field and mechanical tests _at_ full power
• Dec 7 Move magnet to RHIC
• Dec 8 - 18 Commissioning of magnet _at_ RHIC
• Power and cooling
• Hook up with RHIC controls
• Dec 21 - Jan 29, 99 Mapping of magnet
• AGS magnet mapping group

14
Summary

• Phobos Magnet is on-track!
• Magnet is delivered to BNL
• Full power tests will be conducted at the AGS
  this month
• The magnet will be moved to RHIC in early
  December
• Magnet mapping will start in January