# Presentation: 182555

## Proton Plan 

- Eric Prebys, FNAL Accelerator Division

## Charge

- Develop a plan for a reasonable set of improvements and operational initiatives to  maximize proton delivery to NuMI and the Booster Neutrino Beam (BNB) over the next ten years or so.
- Estimate the budget and timeline for these improvements.
- Estimate proton delivery to both beam lines if the Plan proceeds on schedule.
- Note:  this plan is *exclusive* of the Proton Driver, which we assume will one day replace the existing Proton Source (Linac+Booster).
- Note: not *yet* fully updated to reflect BTeV decision

## Review: What Limits Total Proton Intensity?

- Maximum number of Protons the Booster can stably accelerate: 5E12
- Maximum average Booster rep. Rate:  currently 7.5 Hz, may have to go to 10 Hz for NuMI+ *(full)* MiniBooNE
- (NUMI only) Maximum number of booster batches the Main Injector can hold: currently 6 *in principle*, possibly go to 11 with fancy loading schemes in the future
- (NUMI only) Minimum Main Injector ramp cycle time (NUMI only): 1.4s+loading time (at least 1/15s**nbatches*)
- Losses in the Booster:
- Above ground radiation
- Damage and/or activation of tunnel components

*Our biggest worry at the moment and probably forever*

## Plan Strategy

**See full document: **BEAMS-DOC-1441
**Increasing the proton delivery from the Booster to NuMI and MiniBooNE**
- Increase maximum average Booster repetition rate.
- Increase acceptance by improving orbit control and beam quality.
**Increasing the beam intensity in the Main Injector for NuMI**
- Main Injector multi-batch operation.
- Slip stacking in Main Injector (requires RF upgrade).
**Improving operational reliability and radiation limitations**
- Linac quad supplies
- Booster and Linac Instrumentation
- Booster RF Upgrade
- Investigate 7835 Problem

## Breakdown of Plan

| WBS | Description |
| --- | --- |
| 1 | Proton Plan |
| 1.1 | Linac Upgrades |
| 1.1.1 | Linac PA Vulnerability |
| 1.1.2 | Linac Quad Power Supplies |
| 1.1.3 | Linac Instrumentation Upgrade |
| 1.2 |  Booster Upgrades |
| 1.2.1 | Determination of Rep Rate Limit |
| 1.2.2 | ORBUMP System |
| 1.2.3 | Corrector System |
| 1.2.4 | 30 Hz Harmonic Upgrade |
| 1.2.5 | Gamma-t System |
| 1.2.6 | Alignment Improvements |
| 1.2.7 | Drift Tube Cooling |
| 1.2.8 | Booster RF Cavity #20 |
| 1.2.9 | Booster Solid State RF PA’s |
| 1.2.10 | Booster Instrumentation Upgrade |
| 1.3 | Main Injector Upgrades |
| 1.3.1 | Large Aperture Quads |
| 1.3.2 | Main Injector Collimator |
| 1.3.3 | NuMI Multi-batch Operation |
| 1.3.4 | Main Injector RF Upgrade |
| 1.4 | Management |

## Review: Main Injector Loading

- The Main Injector has six usable “slots”, into which Booster batches may be placed.
- More batches may be loaded, using “slip stacking”, in which batches are injected at slightly different energy, drift together, and are captures as one batch (with at least twice the longitudinal emittance).

## Main Injector Loading (cont’d)

- Initial NuMI operation (“2+5”):
- Two batches will be slip stacked for antiproton production.
- Five more batches will be loaded for NuMI
- All will be accelerated together.
- Ultimate NuMI operation (“2+9”):
- Five batches will be loaded into the Main Injector, leaving one empty slot.
- Six more batches will be loaded and slipped with the first to make two for antiproton production and 9 for NuMI.
- This is beyond the capacity of the current RF system.

## Main Injector RF 101

- Our present system:
- Number of cavities: 18
- Total Power Available: 175 kW/cavity (single PA)
- Total Power dissipated: 58.6 kW/cavity
- Power available for acceleration: 116.4 kW/cavity
- Maximum acceleration rate: 200 GeV/s
- In the absence of beam loading compensation, an RF system is stable until the energy expended in accelerating the beam is *equal* to the energy dissipated in the cavity.
- Feed forward loops can increase this stability threshold
- For our system
- Maximum guaranteed stable intensity: 3.3E13 protons
- Power limited intensity: 6.5E13 protons

## Options

- By adding an additional (175/2 – 58.6 =) 28.9 kW passive load to each cavity, we could ensure 87.5 kW of power for stable acceleration
- 4.9E13 proton per batch limit
- Each cavity has an additional port for a second PA, potentially giving 350 kW of total power.
- This could potentially give
- 9.8E13 protons/batch in the most conservative case (175 kW power dissipation)
- Possibly higher with feedback loops

## Proton Projections

- Phases of Operation
- Phase I
- After this shutdown
- Dogleg problem ameliorated
- Booster limited to 7.5Hz total repetition rate
- Main Injector limited to 4E13 protons (2+5 operation)
- Phase II
- After 2005 shutdown
- ORBUMP replaced
- RF cooling finished
- Booster capable of 9Hz operation
- MI still limited
- Phase III
- After 2006 shutdown
- MI RF upgrade complete
- 2+9 operation to NuMI

- 2007

## Predicted Peak Proton Intensity Limits

- Actual

## Calculating NuMI PoT

- Even the fallback scenario accommodates NuMI operation.
- Assume the following
- Booster batch intensity rises steadily to 5.5E12 over the next three years.
- Ramp up to full 2+5 operation by April 2005
- Ramp up to full 2+9 batch slipstacked operation a few months after MI RF upgrade.
- 90% efficiency for slip stacking.
- 10 month operation each year.
- 81% total uptime for remainder of year
- based on MiniBooNE. Includes scheduled and unscheduled downtime
- 90% avg/peak operating efficiency
- 10% down time for shot setup
- 5% down time for fast Recycler transfers
- 5% down time during 2005 for Ecool accesses.
- Does NOT include SY120

## Machine Loading

## “Design” PoT

|  | Booster
Batch Size | Main Injector Load | CycleTime | MI Intensity | Booster Rate* | Total Proton Rate | Annual Rate at  end of Phase |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  | (AP + NuMI) | (sec) | (protons) | (Hz) | (p/hr) | NuMI | BNB |
| Actual Operation |  |  |  |  |  |  |  |  |
| July, 04 | 5.0E+12 | 1+0 | 2.0 | 0.5E+13 | 5.1 | 0.8E+17 | 0 | 3.3E+20 |
| Proton Plan |  |  |  |  |  |  |  |  |
| Phase I | 5.10E+12 | 2+12+5 | 2.0 | 3.6E+13 | 6.3 | 1.0E+17 | 2.0E+20 | 1.5E+20 |
| Phase II | 5.3E+12 | 2+5 | 2.0 | 3.7E+13 | 7.5 | 1.2E+17 | 2.2E+20 | 2.8E+20 |
| Phase III | 5.50E+12  | 2+9 | 2.2 | 6.0E+13 | 8.3 | 1.5E+17 | 3.4E+20 | 2.2E+20 |
| Beyond Scope of Present Plan |  |  |  |  |  |  |  |  |
| 11 Hz | 5.50E+12 | 2+9 | 2.2 | 6.1E+13 | 11.0 | 2.0E+17 | 3.4E+20 | 5.0E+20 |

## Fallback Scenarios

- NuMI
- Project totals if the MI RF upgrade is delayed by a year *(probable!!)*
- Project totals if slip stacking fails entirely for one reason or another *(pessimistic)*
- BNB
- Project totals if both the MI RF upgrade and the corrector upgrade are delayed by a year *(probable)*
- Project totals if the aperture improvements have only 25% of their calculated benefit *(pessimistic)*

## Since Initial Report

- The first “reality check”:
- Funding limited
- Defer indefinitely:
- Linac quad upgrade
- 30 Hz harmonic
- Booster solid state RF
- Instrumentation upgrade
- Significantly delay:
- Main Injector RF
- Effect of canceling BTeV:
- Budget very front-loaded
- Most things back:
- Probably not Booster solid state RF
- Most likely scenario “delayed”:
- Booster correctors and MI RF installed in 07 shutdown.

## Fallback Projections (delayed scenario most likely)

- BNB only during shot setup

- BNB *benefits* from delayed slip stacking

## Extra Slides for Questions...

## Status of Major Work

- Linac
- 7835 Task force
- Burle OK for now
- Buy tubes (12 extra by end of 06)
- LEL quad power supplies
- Working on prototype, based on HEL supplies
- Booster:
- ORBUMP magnets:
- First magnet built and tested, proceeding with the rest
- ORBUMP PS:
- Procuring and assembling
- Corrector System
- Conceptual design complete
- Working on detailed design
- Working on PS specs

## Status of Major Work

- Main Injector
- Large Aperture Quads
- In fabrication.  Will be ready for 05 shutdown
- 5-batch commissioning
- In progress
- Loss mitigation/collimator system
- Working group formed
- Identifying collimator candidates for MI-8
- Starting ring collimator system design based on Booster
- Miscellaneous projects (added since first draft)
- Barrier bucket cavity:
- In procurement
- Injection kicker modification:
- Being designed

## Status of MI RF Work

- Build prototype cavity
- Passive load:
- Existing port?
- Cut new port?
- Second PA
- Carry out a series of studies in the Main Injector
- Determine effectiveness of feed-forward loops
- Determine optimal passive load and predict intensity limit for one- and two- PA scenarios
- Refine cost estimate for passive load and PA upgrades.
- Use this information to determine longer range plan.

## Status of Plan

- Working with Project Support to complete WBS chart.
- All major elements at least have reasonably accurate placeholders.

## Evaluate Effect of Booster Improvements

- Calculate effect of various improvments based on increased acceptance (a la McGinnis):
- Use:

- Effective aperture reduction

| Condition | Date | A | max D | max beta | Acceptance | Relative |
| --- | --- | --- | --- | --- | --- | --- |
|   | Completed | (mm) | (m) | (m) | (-mm-mr) | Increase (%) |
| Start of MiniBooNE | --- | 10 | 6.2 | 45.8 | 15.7 | -15 |
| Dogleg 3 Fix | Oct-03 | 10 | 4.5 | 40.8 | 18.4 | 0 |
| Dogleg 13 Fix | Oct-04 | 10 | 3.8 | 36.1 | 21.0 | 14 |
| Alignment | Oct-05 | 8 | 3.8 | 36.1 | 24.3 | 32 |
| ORBUMP | Oct-05 | 5 | 3.8 | 36.1 | 29.5 | 60 |
| correctors | Oct-06 | 2 | 3.8 | 36.1 | 35.2 | 92 |
| Ideal | --- | 0 | 3.19 | 33.7 | 42.3 | 130 |

## Effect on Max Proton Intensity

- Prior to this shutdown, regularly delivering 7.5E16pph with ~40% reduction in activation around most of the Booster.
- Assume after another year of tuning and collimator optimization, we could have hit 1E17 pph with no other improvments (“fallback” = .9E17).
- Operational experience: tuning asymptotically approaches benefit of a particular improvement:
- Assume after one year of tuning, 50% of the benefit of a particular improvement is realized (fallback = 25%).

| Date | “Design” Limit(1E16 p/hr) | FallbackLimit(1E16 p/hr) | Comment |
| --- | --- | --- | --- |
| 1/2006 | 10.7 | 9.3 | Effect of collimators, dogleg fix, plus some alignment |
| 1/2007 | 13.0 | 10.4 | Alignment and ORBUMP |
| 1/2008 | 14.6 | 11.0 | New corrector system |

## Estimating PoT

- Even the fallback proton scenario accommodates NuMI operation.
- Total proton output continues to be limited by radiation losses, rather than Booster repetition rate.
- We assume:
- NuMI and antiproton production get what they need
- The BNB gets whatever it can beyond that, within the total output limit of the Booster
- This is a programmatic decision:
- Protons can be diverted from NuMI to the BNB, but not the other way around.
- The BMB PoT estimates are extremely sensitive to the total proton limit, which is uncertain.

## Calculating BNB PoT

- Trickier:
- Still limited by beam loss, NOT rep. rate.
- Assume antiproton and NuMI have priority, so
- BNB VERY sensitive to proton limit and its fluctuations.
- Use:
- 	(avg pph) = (pph lim.)*η – (NuMI pph) – (pbar pph)
- Also assume:
- 10 month operation
- 81% up time (based on 2004)
- 5% downtime in 2005 for ECool access
- BNB gets all the beam during shot setup (10% of the time)

- Avg/pk ~ 86% from July 2004 MiniBooNE operation

- Booster output limit, as discussed

## “Design”  Totals (almost certainly outdated)

- Last 4 weeks