Proton Plans at Fermilab

Robert Zwaska - Fermilab

Science and Engineering at Henderson-

DUSEL Capstone WorkshopStony Brook University

May 5, 2006

Outline

I. Introduction to the accelerator complex

II. Planned and possible upgrades

III. Proton power projections

Making Neutrino Beams• Two operating beams at Fermilab

– Use 8 or 120 GeV protons– Secondaries produced with solid target and focused

• A rough figure of merit: proton power on target– Average current × Beam energy– 120 GeV beam does better

• Other factors (not covered):– Neutrino beam elements & design– Detector size & design

NuMI

The Main Injector Today

Batch 1 (PBar)

Batch 2

Batch 3

Batch 4

Batch 5

Batch 6

Booster

Main Injector

• Provides high power, 120 GeV proton beam– 80 kW for antiproton production– 170 kW for neutrino production

• Takes 6 or 7 batches from the 8 GeV Booster @ 15 Hz– 4-5 × 1012 protons per Booster batch

• Total cycle time ≥ 1.467 s + batches/15

NuMI

Past-Year NuMI Running• Average power of 165 kW in the last few months

• Maximum beam power of 270 kW down the NuMI line (stably for ~ ½ hour)

• Peak intensity of 3×1013 ppp on the NuMI target

Pro

ton s

per

pu

l se

(10

1 2)

May 1 ‘05

10

20

30

March 1‘06

Pow

er (

kW)

100

May 1‘05

March 1‘06

200

300

1st Booster Batch Injected into MI

2nd Booster Batch

Merged bunch train in MI

E

1st Batch 2nd Batch

Decelerate

Accelerate

Time

• Merge two booster batches through RF manipulations

K. Seiya et. al., PAC2003

Slip-stacking (Proton Plan)

Doubles the azimuthal charge in the Main InjectorBooster loading time is doubled

→ 440 kW of protons

SnuMI: Recycler as an 8 GeV proton accumulator

• After the Collider program is terminated, we can use the Recycler as a proton accumulator

– Booster batches are injected at 15 Hz rep rate

• Accumulate protons from the Booster while MI is running

– save 0.4 s for each 6 Booster batches injected

• Can also slip-stack beam in the Recycler

– Up to 12 Booster batches injected (save 0.8 s)

• 5.4×1013 ppp every 1.467 s → 700 kW

D. McGinnis, Beams-doc-1782, 2138

SNuMI: Momentum stacking in the Accumulator

• After the Collider program is terminated, we can also use the Accumulator

in the Anti-proton Source as a proton accumulator

– Momentum stack 4 (3) Booster in Accumulator batches every 267 (200) ms

– Limit Booster batch size to ~ 4×1012 protons

– Box Car stack in the Recycler

– Load in a new Accumulator batch every 267 (200) ms

• 6 Accumulator (24 or 18 Booster) batches

in Recycler

• Load the Main Injector in a single turn

• 9.1×1013 every 1.6 s → 1.1 MW

– 7.2×1013 every 1.33 s → 1.0 MW

D. McGinnis, Beams-doc-1782, 2138

High Intensity Neutrino Source• 8 GeV Superconducting Linac as replacement for Booster

– Nominal injection charge ~1.5×1014 ppp

• Cycling every 1.4 s corresponds to a beam power of 2 MW at 120 GeV– Requires major upgrades to Main Injector RF

• Significant MI RF and magnet upgrades could reduce acceleration time– Maybe up to 4 MW

Proton Power Projections

• Proton plan (in progress)– Ramp to 440 kW in 2009

• Recycler/Accumulator upgrades (in design – not approved yet)– One year shutdown in 2010

– Ramp to 1.1 MW (700 kW) in 2012

• High Intensity Neutrino Source (under consideration)– 2 MW sometime in the future

0200400600800

100012001400160018002000

Pea

k B

eam

Po

wer

(k

W)

2006 2008 2010 2012 20xx

Note: ~ 1.7×107 s/yr (effective, at peak power)

Lowering the primary proton energy ?

D. Wolff

Injection dwell time 80 ms Flattop time 50 ms Maximum dp/dt 240 GeV/s

120 GeV, 1.34 s

50 GeV, 0.81 s

40 GeV, 0.73 s

30 GeV, 0.62 s

this is achievable now (conservative) limit injection dwell time to ~ 30 ms ? faster down ramp ?

Proton Energy Scaling• Reducing proton beam energy does not results in an equal reduction in cycle time

– Worst for cases where Booster is heavily utilized

• Neutrino beams based on lower-energy protons will have lower beam power

0

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1000

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20 40 60 80 100 120

Primary Proton Energy (GeV)

Pea

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kW

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CurrentProton PlanRecyclerAccumulatorHINS

Conclusions• Fermilab proton complex can be upgraded to produce a Neutrino Superbeam

– 320 kW peak (250 kW ave.) available today

– 440 kW upgrades are in progress • Proton Plan → E. Prebys et al.

– 700 kW & 1.1 MW upgrades are under study (likely?)• SNuMI → A. Marchionni et al.

– ≥ 2 MW beams are under consideration• HINS → G. Appolinari et al.

• Primary proton energy needs to be understood– Lowering proton energy below 120 GeV always reduces the beam power on target

• Neutrino beam production needs to be considered– There is no beamline to Henderson

– Does not need to be a conventional beam:• Neutrino Factory (A. Tollestrup et al.)

• Beta Beam (A. Jansson)