# Presentation: 870350

## Proton PlanORBUMP and 400 MeV Upgrades WBS 1.2.2 Director’s Review August 2005

- J. Lackey/F. G. Garcia

## Current Situation

- Booster supports
- Pbar production ~ 4.5X1012 protons/cycle @ ~1 Hz
- Collider protons ~ 3-4X1011 protons/coal. bunch
- MiniBooNE         ~ 3-4x1012 protons/cycle @ ~2-3 Hz
- NuMI                 ~ 4.5x1012 protons/cycle @ ~2.0 Hz
- Switchyard 120  ~ 8.3x1011 protons/cycle @ ~ 0.3 Hz
- Protons deliverable by Booster are limited by
-  Activation of beam line components
-  Rate at which certain elements are capable of running
- Currently limited to 7.5 Hz
- The injection bump (OrBump) system is a limiting factor!
-  OrBump limitations
-  Magnets
- Limited to 7.5 Hz due to temperature
-  Power supply:
- Charging supply reliability questionable beyond ~ 9 Hz
- Age of electrical components raise longevity concerns

## A little bit of history...

-  Rate limitation was not a concern prior to MiniBooNE.
-  Initial efforts to achieve higher rates was moderately successful.
- Common failures were temperature related
- Limiting factor was power supply component failures
- In May’04 all the capacitors were changed and the power supply failures decreased considerably

**Time**

## OrBump Temperature History

- Power Supply
- Better stability even at high temperature
- Rate
- Increase from
- 3-4.5  Hz range to
- 5-6.5  Hz range
- Magnets
- Temperature of the magnets became the limiting factor
- Biggest concern is how soon the magnets will fail due to thermal cycling

## Goal and Requirements

- GOAL
- Making Booster capable of running beam at 15 Hz
-  Requirements
- Eliminate OrBump limiting factors
- OrBump System Improvements
- OrBump Power Supply (WBS 1.2.2.2)
- Operational supply capable of running at 9 Hz
- New supply been built will be capable of running at 15 Hz
-  OrBump Magnets (WBS 1.2.2.1)
- Operational magnets are limited by heating to 7.5 Hz
- New magnets will be LCW cooled for temperature regulation

## OrBump Power Supply

- _Power Supply specifications_
- Nominal pulse amplitude = 15 kA
- Maximum pulse amplitude = 17.5 kA
- Maximum flat top duration = 50 μsec
- Rise/Fall time
- Minimum = 30 μsec
- Maximum = 40 μsec
- Nominal repetition rate = 15 Hz

**MP02 Power Supply**

- _Current Status_
-  Charging supply assembly underway
-  Cabinet assembly underway
-  Ready for installation beginning of Nov’05

- New OrBump PS
-   will look like this one

## OrBump Magnet

| Parameter | Value | Units |
| --- | --- | --- |
| ∫By dl @ 15 kA | 0.1676 | T-m |
| Ferrite length | 523.3 | mm |
| Effective length | 558.5 | mm |
| Aperture gap | 65.1 | mm |
| Aperture width | 135.1 | mm |
| Inductance | 1.83 | μH |
| Resistance | <1 | mΩ |
| Quadrupole | 1x10-4 | mm-1 |

- Ferrite core

- Single turn conductor

- Power leads

- Cooling water leads

- Vacuum skin

- Asymmetry produces gradient

- Courtesy of D. Harding

- _Current Status_
-  4(6) magnets assembled
-  Field shape development continues
-  Magnets production complete in Oct’05

- Backups
- 29,30

## Plan of action

- OrBump replacement is targeted for 2005 shutdown
- Initial plan
- Replace 4 magnets and 1 power supply in current injection scheme
- The injection girder is a high radiation area and presents a hazard during installation
- L1 activation is ~ 600 mr/hr @ 1 foot
- Plan evolves to remove the girder and install a new one
- Complete rebuild of the injection section is needed
-  Alternative injection scheme layout was pursued
- Workable layout was found
- (BEAMS-DOC-1784-v1, M. Popovic)

## Current Injection Scheme

- 4-bump injection scheme
- DC septum magnet bends the injected beam parallel to the circulating beam
- The circulating beam is “bumped out” so that the injected and circulated beam pass together through the injection foil

## Current Injection Girder

## New Injection Scheme

- 3-bump injection scheme
- No need for DC septum magnet
- Reducing the radiation hazard during installation
- Increase vertical aperture entering OrBump from 1.5” to 3.25”
- Line is simpler
- Less components
- The 3-bump scheme requires only 15 kA rather than 30 kA from the power supply
- OrBump magnets are further apart from each other
- Reduce focusing edge effects

## Girder Layout

## Transfer Line Activation History

- ~70% reduction in tunnel activation without DC Septum

## ComparisonCurrent Scheme      vs            New Scheme

- Vertical beta function is somewhat smaller (~23%)
- Better matching to the horizontal/vertical dispersion seems promising

## New  Injection (cont.)

|  | Vertical | Horizontal |
| --- | --- | --- |
| Betatron | negligible | negligible |
| Dispersion | ~1% | ~7% |

- The lattice matching section shows flexibility for Booster injection tune
-      (bands represent  20% variation of injection beam parameters)

- Best emittance dilution
-       while matching
-      Booster injection

- Still an improvement over
- current condition

## Other sources of emittance dilution

| Possible sources | Emittance dilution (%) |
| --- | --- |
| Power supply jitter
( 1% stability) | ~1%   (position only)
~10% (angle and position) |
| Incoming beam variation | ~10% (both planes) |
| OrBump magnet 
(Quadrupole component) | negligible |
| Closed orbit variation | negligible |

- Besides the amplitude and dispersion mismatch, there are
-   other potential sources of emittance dilution

- Backups
- 26,27,28

## List of  Overall Improvements

- 100% duty factor operation possible
- Edge focusing effects minimized
- Vertical Lattice distortions reduced
- Smaller beam size
- Larger effective aperture
- PS current reduced by 1/2
- Lower rms current
- Lower heating effects
- Injection apertures larger
- Injection Beam losses lower
- Injecting onto ideal machine orbit
- Injection phase space painting now a possibility

## Commissioning Plan

- We plan to establish beam onto 8 GeV dump prior normal operation resumes
- Prerequisite of commissioning
- After reinstallation of line components a series of checks will be carried out, such as
- Magnet connections and polarities
- Visual check and confirmation that all LCW valves are working properly
- Visual inspection of the vacuum valve positions
- Instrumentation function and readout polarity
- And so on....
- Initial beam commissioning
- Start at lower intensity and rep rate
- Establish beam onto Linac dump
- Transport beam onto injection girder. Apply theoretical tune on quads belonging to the matching section to Booster
- Initial checks of beam optics and rough correction as needed
- Correct beam trajectories along transport using correctors
- Evaluate any beam loss concerns and tightest aperture clearance
- Establish circulating beam
- Increase intensity and start tuning for efficiency
- Commissioning period expect to last a couple of weeks

## Management

-  AD Electrical Tech
-  AD Mechanical Tech
-  TD Electrical Tech
-  TD Mechanical Tech

-  AD Electrical Tech
-  AD Mechanical Tech
-  PPD Survey Tech

-  AD Electrical Tech
-  AD Mechanical Tech
-  PPD Survey Tech
-  Contractor Tech

- Personnel

## OrBump SystemSchedule Information

## OrBump System Cost Information

- RunII

## Manpower issues

- Installation is scheduled to happen during holiday season
- Available manpower could be reduced due to vacation request during holiday season
- For instance, if 2 people take vacation during holiday the project will slide for ~1.3 days
- There is always a risk for manpower been removed from one task to resolve a crisis situation at another task.

## Risk Analysis

- _Risk 1:_ Expose workers to a high radiation area
- _Mitigation:_  Follow ALARA. Plan under development.
- Plan the tasks carefully
- Conduct a radiation survey 1 week prior the job start
- After removal of components, redo survey and respond to the findings accordingly
- _Risk 2_: Poor transmission into Booster due to change on injection scheme
- _Mitigation_:  Internal review was conducted in Apr’05. No major concerns were raised related to the injection scheme and magnet reorganization. One could overcome the poor transmission by tuning.
- _Risk 3_: Infant mortality of the new equipment
- _Mitigation_:  Bench testing prior to installation and commissioning period will be performed on the magnets and power supply.

## Conclusion

- OrBump magnets and power supply need to be upgraded in order to allow Booster achieve operations at 15 Hz.
-  A new injection scheme has been proposed
- Benefits of 3-bump injection scheme
- OrBump installation and 400 MeV reconfiguration will take place during next shutdown.
- Project duration fits into the framework of the 2005 shutdown.

## BACKUP SLIDES

## Emittance dilution due to Amplitude and Dispersion function mismatch

## Emittance dilution due toposition mismatch

- Emittance dilution due toposition mismatch

**Reference:** M.J. Syphers, *Injection Mismatch and Phase Space Dilution, *p29

-  Power supply jitter: 1%
-     xeq= 1.5 mm
-     x’  = 0.2 mrad
-  Incoming beam variation

## Quadrupole Field in the OrBump Magnet

- The result of the beam passing through different locations of the quadrupole field is a net dipole effect on the closed orbit
- The amplitude of this dipole error changes as the OrBump power supply ramps down
- The maximum distortion is ~ 0.7mm

## Field Measurements

- NEW

-  OLD

##                 OrBumps

- Operational OrBumpS
- Designed to run at 15 kA max, 300 Arms,
- 20% duty factor.  NO cooling.
- Presently running at ~50% duty factor.
- Heating, Injection Error, Sextupole, Radiation damage.
- New OrBumps
- Designed to run at 15 kA max, 1500 Arms,
- 100% duty factor.  ~16% Stronger.
- Built with ferrite and coil cooling.
- Radiation hardened construction.
- Fit in the same footprint as existing magnets.
- New Power Supply

## Tracking Study of New Injection

## Tracking Study of New Injection

- From Drozhdin’s paper, p3

## Tracking Study of New Injection

- From Drozhdin’s paper, p8

## Tracking Study of New Injection

## Current vs New Injection Scheme Layout

- Current Scheme

- New Scheme

- Girder

## Girder Layout

## New Injection Layout

- girder