f Antiproton Acceptance Two Projects: 1. High Gradient Lithium Lens
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Transcript f Antiproton Acceptance Two Projects: 1. High Gradient Lithium Lens
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Antiproton Acceptance
Two Projects:
1. High Gradient Lithium Lens
Project Leader: Jim Morgan
2. AP2 Beamline and Debuncher Acceptance
Improvements
Project Leader: Keith Gollwitzer
2/5/2003
Steve Werkema
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Antiproton Acceptance
Basic Layout
Scope of Antiproton
Acceptance
projects:
Target station downstream of
target
AP2 beamline
Debuncher ring
2/5/2003
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Antiproton Acceptance
Motivation
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 of`p phase space distribution at the center of the target
Dp/p < 2.25%, contains only`p’s within acceptance of Li Lens
2/5/2003
Steve Werkema
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Antiproton Acceptance
High Gradient Lithium Lens - Parameters
Gradient
Radius
Lifetime
29 cm
Present
Upgrade
745 T/m
1000 T/m
1.0 cm
1.0 cm
9106 pulses
10106 pulses
81cm
2/5/2003
Pulsed
Magnet
Li Lens
Target
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Antiproton Acceptance
High Gradient Lithium Lens - Motivation
10% increase in`p
yield by raising the
gradient from 745
T/m to 1000 T/m
Factor of 2.3
increase in`p yield
by raising the
gradient to 1000 T/m
and doubling the
AP2/Debuncher
Admittance
Note: The`p yield
improvement per gradient
increase is greater at
larger admittances
2/5/2003
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Antiproton Acceptance
High Gradient Lithium Lens – Present Performance
Gradient
(T/m)
1000
900
800
745
700
Average Number of
Pulses to Failure
<500,000
1,000,000
3,000,000
9,000,000
>10,000,000
With the present design, the gradient would have to be
lowered to 700 T/m to achieve a lifetime of 10,000,000 pulses.
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Antiproton Acceptance
High 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
2/5/2003
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2/5/2003
Antiproton Acceptance
High Gradient Lithium Lens – Present Li Lens
Steve Werkema
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Antiproton Acceptance
High 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:
o 4 septum fractures, 1 water leak (control)
o Preliminary analysis suggests that cracking had been initiated
prior to pulsing the lens
Result: Improved quality control during fabrication of
new lenses
2/5/2003
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Antiproton Acceptance
High Gradient Lithium Lens – New design
Features:
Diffusion bonded titanium body
Thicker septum
Li buffer volumes eliminated
2/5/2003
Steve Werkema
Prototype #1 is
under construction
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Antiproton Acceptance
High 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)
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Antiproton Acceptance
AP2 & Debuncher Acceptance – Motivation
`p phase space
distribution exiting the
lens for a gradient of
750 T/m.
Dp/p < 2.25%
Beamline optics have
been adjusted to match
Li lens aperture.
Blue dots are horizontal,
Red dots are vertical
(i.e. 2 points per`p).
Goal: 40 p mm-mrad transverse admittance
2/5/2003
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Antiproton Acceptance
AP2 & 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%
2/5/2003
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Antiproton Acceptance
AP2 & 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
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AP2 & 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
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AP2 & 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
Measure AP2 + Debuncher admittance
(develop measurement techniques)
Measure AP2 + Debuncher momentum aperture
2/5/2003
Steve Werkema
(12 hr)
(20 hr)
(8 hr)
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Antiproton Acceptance
AP2 & 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.
2/5/2003
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Antiproton Acceptance
Conclusion
Present`p yield:
1710-6 `p/POT
Expected`p yield:
4010-6 `p/POT
58 1010`p/hr
delivered to the
Accumulator for
stacking
For:
81012 POT/pulse
(slip stacking)
2.0 sec cycle time
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