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
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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
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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
9106 pulses
10106 pulses
81cm
2/5/2003
Pulsed
Magnet
Li Lens
Target
3
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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
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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.
2/5/2003
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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
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2/5/2003
Antiproton Acceptance
High Gradient Lithium Lens – Present Li Lens
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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
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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
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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%
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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.
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Antiproton Acceptance
Conclusion
Present`p yield:
1710-6 `p/POT
Expected`p yield:
4010-6 `p/POT
 58 1010`p/hr
delivered to the
Accumulator for
stacking
For:
81012 POT/pulse
(slip stacking)
2.0 sec cycle time
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