Antiproton Acceptance

1
Antiproton Acceptance

• Two Projects
• High Gradient Lithium Lens
• Project Leader Jim Morgan
• AP2 Beamline and Debuncher Acceptance
  Improvements
• Project Leader Keith Gollwitzer

2
Antiproton AcceptanceBasic Layout

• Scope of Antiproton Acceptance projects
• Target station - downstream of target
• AP2 beamline
• Debuncher ring

3
Antiproton AcceptanceMotivation

• Increase the number of antiprotons collected from
  the target by
• increasing the gradient of the collection lens
• increasing the admittance of the AP2 beamline
  and the Debuncher

MARS model ofp phase space distribution at the
center of the target Dp/p lt 2.25, contains
onlyps within acceptance of Li Lens
4
Antiproton AcceptanceHigh Gradient Lithium Lens
- Parameters
Present Upgrade
Gradient 745 T/m 1000 T/m
Radius 1.0 cm 1.0 cm
Lifetime 9106 pulses 10106 pulses
5
Antiproton AcceptanceHigh Gradient Lithium Lens
- Motivation

• 10 increase inp yield by raising the gradient
  from 745 T/m to 1000 T/m
• Factor of 2.3 increase inp yield by raising the
  gradient to 1000 T/m and doubling the
  AP2/Debuncher Admittance
• Note Thep yield improvement per gradient
  increase is greater at larger admittances

6
Antiproton AcceptanceHigh Gradient Lithium Lens
Present Performance
Gradient (T/m) Average Number of Pulses to Failure
1000 lt500,000
900 1,000,000
800 3,000,000
745 9,000,000
700 gt10,000,000

• With the present design, the gradient would have
  to be lowered to 700 T/m to achieve a lifetime of
  10,000,000 pulses.

7
Antiproton AcceptanceHigh Gradient Lithium Lens
Goals Action Plan

• Goal Operate a Lithium lens --
• at a gradient of at least 1000 T/m
• for at least 10 million pulses
• Action Plan (in process for past 5 years)
• Liquid Li Lens development at BINP
• Improvement to present design
• FEA model of present design
• Autopsies of failed lenses
• New solid Li Lens design

8
Antiproton AcceptanceHigh Gradient Lithium Lens
Present Li Lens
9
Antiproton AcceptanceHigh Gradient Lithium Lens
Status

• Liquid Lithium Lens development
• Project terminated in FY 2002 without producing
  a viable
• lens prototype.
• Existing Lens improvements
• FEA Peak stresses during lens operation are well
  below the fatigue strength of the titanium septum
• ? failure initiated by another mechanism
• Autopsies of five failed lenses
• 4 septum fractures, 1 water leak (control)
• Preliminary analysis suggests that cracking had
  been initiated
• prior to pulsing the lens
• Result Improved quality control during
  fabrication of new lenses

10
Antiproton AcceptanceHigh Gradient Lithium Lens
New design

• Features
• Diffusion bonded titanium body
• Thicker septum
• Li buffer volumes eliminated

Prototype 1 is under construction
11
Antiproton AcceptanceHigh Gradient Lithium Lens
Near Future

• Complete and test new lens design prototype 1
• Lens 22 autopsy
• Longest lived lens, did not fail during pulsing
• Refine and expand FEA model
• Operate a lens constructed with improved quality
  control procedures
• Operate for 1 month at 745 T/m then increase to
  820 T/m
• Construct 2 new lenses with a thicker septum (20
  50 thicker)

12
Antiproton AcceptanceAP2 Debuncher Acceptance
Motivation
p phase space distribution exiting the lens for
a gradient of 750 T/m. Dp/p lt 2.25 Beamline
optics have been adjusted to match Li lens
aperture. Blue dots are horizontal, Red dots
are vertical (i.e. 2 points perp).

• Goal 40 p mm-mrad transverse admittance

13
Antiproton AcceptanceAP2 Debuncher Acceptance
Parameters
Recent Measurements Physical Aperture Goal
Horizontal (mm-mrad) 20 1.5 p 40 p 40 p
Vertical (p mm-mrad) 12 1.5 p 40 p 40 p
Momentum 2.25 2.25 2.25
14
Antiproton AcceptanceAP2 Debuncher Acceptance
Issues

• Identification of limiting apertures
• Correction of known limiting apertures
• Beamline element alignment
• Orbit control
• More AP2 trim dipoles
• Debuncher moveable quad stands
• Element redesign
• Instrumentation issues
• BPMs

15
Antiproton AcceptanceAP2 Debuncher Acceptance
Status

• The following projects are presently underway
• AP2 and Debuncher documentation survey (TD)
• Determine physical aperture everywhere in
  beamline from drawings and other documentation
• AP2 line trim dipoles
• 4 NDB dipole trims have been installed in the AP2
  line during the past year
• Install moveable stands on selected Debuncher
  quads
• Cables were pulled during the January 2003
  shutdown. No new stands have been installed.
• Beam studies
• 88 Hours of beam studies in past year (next
  slide)
• Debuncher BPM upgrade
• Have completed beam testing of a single BPM
  electronics prototype
• One sector of the Debuncher was instrumented
  during the January 2003 shutdown with upgraded
  BPM electronics

16
Antiproton AcceptanceAP2 Debuncher Acceptance
Completed Studies

• Beam studies completed within the past year
• Reverse proton studies
• Re-commission and develop various beam
  manipulation procedures (Debuncher, AP2, DRF3,
  DRF1) (36 hr)
• Problem have not yet been able to see beam on
  AP2 BPMs
• Debuncher BPMs (Re-commission old electronics and
  prototype testing of new electronics) (8 hr)
• Aperture measurements (4 hr)
• Stacking studies
• AP2 line orbit correction (12 hr)
• Measure AP2 Debuncher admittance
• (develop measurement techniques) (20 hr)
• Measure AP2 Debuncher momentum aperture (8 hr)

17
Antiproton AcceptanceAP2 Debuncher Acceptance
The Future

• Complete documentation survey
• Complete Debuncher BPM upgrade
• Install Debuncher moveable quad stands
• Build prototype portable quad alignment device
• Element redesign
• Beam Studies
• Commission new hardware
• Develop procedures (upgrade and test software
  controls)
• Correct AP2 and Debuncher orbits
• Note much of the studies plan requires the new
  Debuncher BPMs and/or completed installation of
  the moveable quad stands.

18
Antiproton AcceptanceConclusion

• Presentp yield
• 17?10-6 p/POT
• Expectedp yield
• 40?10-6 p/POT
• ? 58 ?1010p/hr
• delivered to the Accumulator for stacking
• For
• 8?1012 POT/pulse
• (slip stacking)
• 2.0 sec cycle time