Accelerator Operations and PIP

Accelerator Operations and PIP

Sergei NagaitsevDOE OHEP briefing6 March 2014

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Accelerator Operations

Fermilab operates a total of 16 km of accelerators and beamlines• A 400-MeV proton linear accelerator (0.15 km)• An 8-GeV Booster synchrotron (0.5 km)• An 8-GeV accumulator ring (3.3 km)• A 120-GeV synchrotron (3.3 km)• A Muon Campus Delivery ring (0.5 km)• Soon: the g-2 ring• Transfer lines and fixed target beam lines (8 km)• Two high power target stations, several low-power targetsAnd maintains• 130 buildings, structures, service bldgs,…

S. Nagaitsev | Operations and PIP

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Fermilab after the Tevatron

• Fermilab operates the largest accelerator complex in the U.S., 2nd largest in the world (even after termination of the Tevatron)

• Most economical, leanest operation of the largest accelerator complex in the US (maybe in the world)

• Apr 2012 – Sep 2013, ~18 months have been spent in shutdown and commissioning, adapting the accelerator complex after the end of the Tevatron era– Present mission: deliver high-intensity proton beams to explore

the Neutrino Sector and rare decays• Fermilab is now ready for the Intensity Frontier program and

investments!


Fermilab Accelerator Complex

Linac: NTF, MTABNB: MicroBooNENuMI: MINOS+, MINERvA, NOvAFixed Target: SeaQuest, Test Beam Facility, M-CenterMuon: g-2, Mu2e (future)

S. Nagaitsev | Operations and PIP4

Take-home message• Operational excellence is our guiding principle.

– 24/7 operation, 6-week/year shutdown, ~80% up-time

• The Proton Improvement Plan (PIP) is crucial to Fermilab accelerator operations– Reliability, availability and proton flux

• The success of Intensity Frontier program depends (from accelerator point of view) on:– Integrated number of protons on target (POT)– Target reliability


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Historic Fermilab Proton Flux


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Neutrino beam delivery over the last 15 years:

• Fermilab has already delivered 3.5 times the number of protons on target to its neutrino experiments than both Asia and Europe combined.

• No one does accelerator-based neutrinos better than Fermilab!


protons on target (x1020)K2K 0.92T2K 6.39OPERA/ICARUS 1.81 9.12 = total Asia + Europe

NuMI 13.90BNB 17.73 31.63 = total Fermilab

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Proton delivery scenario (approximate)


0

0.5

1

1.5

2

2.5

3

3.5

2014 2015 2016 2017 2018 2019 2020 2021 2022

POT/

quar

ter,

(x10

20)

FY

7.5 Hz

15 Hz (after PIP)

NuMI

BNB

mu2e

g-2

SY120“tax”

Total beam thru Booster

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High-power Targetry


• Target– Solid, Liquid, Rotating, Rastered

• Other production devices:– Collection optics (horns,

solenoids)– Monitors & Instrumentation (high

radiation/temperature)– Primary Beam window– Absorbers/Collimators

• Facility Operations:– Remote Handling– Shielding & Radiation Transport– Air Handling– Cooling Systems– Waste stream

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Neutrino Target Facility Comparison


NuMI (

FNAL)

NOvA (F

NAL)T2

K (J-P

ARC)

LBNE –1.2 MW (FNAL)

LBNE –2.4 MW(FNAL)

SNS (ORNL)for reference

CNGS (CERN)

Blue – Design Beam Power

Green – Actual Beam Power

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Main High-Power Target Challenges


Thermal Shock Radiation DamageBeam Windows

Also: radiation protection, remote handling


NuMI and NOvA targets

• NuMI target must fit inside horn 1 • target removed during

shutdown• NOvA target is installed upstream

of horn 1 (neutrino energy from off-axis angle)

• Physics requirements allowed for changes in the design

• mechanically more robust

120 GeV protons

Focusing Horns

2 m

675 m

15 m 30 m

NuMI target

Decay Pipe

π-

π+

νμ

νμ

NuMI

NOvA

New Fermilab Targets in the Next Decade• g-2 (previously P-bar Source Target Station):

– Commissioning in 2016-17– High-Z rotating target (inconel 718 alloy)– Lithium lens at ~12 Hz (average)– Pulsed Magnet (Momentum selection)

• Mu2e– Commissioning in 2019-20– High-Z, radiatively cooled target (tungsten)– Mounted in large SC solenoid– Only 8 kW beam power, but radiation protection

issues are a challenge due to solenoid• LBNE

– Commissioning in 2023-24– 1.2 MW beam power– Low-Z target (graphite/beryllium?)– Difficult target, horn, beam window, radiation

protection, remote handling challenges.


p-bar lithium lens

Mu2e target concept

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Fermilab Booster


• Booster is a resonant machine running at 15 Hz • RF is pulsed, limited to ~7.5 Hz

– at higher frequencies the cavities spark– at higher frequencies the tuners overheat– Refurbishment plan to achieve 15 Hz is part of PIP

• There is an RF pre-pulse associated with beam cycles– It means that the beam pulse rate is less than 7.5 Hz

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Booster performance

• In FY14, we expect to meet the Booster beam performance metric.


Accelerator Performance for NuMI• Started delivering protons to NuMI in 2005

– ~1.55e21 in 7 years: NOvA goal is 3.6e21 – Most intense high energy neutrino beam in the world


320 kW on target

• Previous operation:– H- linac at ~35 mA – Charge exchange injection into Booster 10-11 turns: 4.3e12– 9 pulses (at 15 Hz) into Main Injector with RF slip stacking– Ramp to 120 GeV at 204 GeV/s and extract to NuMI target– 3.7e13 / 2.2 sec cycle 323 kW


Increasing Beam Power to 700 kW

• Move slip-stacking to recycler

• 11 batch -> 12 batch• Increase Main Injector

ramp rate (204 GeV/s -> 240 GeV/s)

• 330 (380) -> 700kW with only ~10% increase in per-pulse intensity

• Peak intensity 10% just more frequent

Mai

n In

ject

orRe

cycl

er


The Plan

• Booster at 4.3e12 ppp, 7.5 Hz ✔• Begin NuMI operation with MI only ✔

– 2.5e13 0.6 Hz (1.67 s cycle)– ~290 kW peak

• Commission Recycler as a proton machine– Injection, extraction, instrumentation, slip stacking ✔– Operational in May 2014– Considering several scenarios on how to ramp the

beam power up• Began SY120 operation at 2e11 ✔

– Raised intensity to 2e12 in January ✔– 8e12 per spill in March


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Main Injector Performance

• We are working hard to meet the challenging POT performance metric


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Recycler status

• 12 Booster batches slip-stacked in the Recycler, transferred to MI and extracted to NuMI target

• Next step: increase beam intensity


SY120 (slow extraction program)

• ~10% Tax on the NuMI program• SeaQuest is running since November• Fermilab Test Beam Facility: very successful

– FY14: scheduled more than 20 experiments• Meson Center test beam:

– Capable of delivering 5 – 85 GeV/c secondaries of either sign.

– Using the same secondary configuration as the MIPP experiment – proven design.

– Initial user will be LArIAT (liquid argon detector test).– May be ready to commission in late March.– Shielding Assessment Approved


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PIP


• The PIP campaign has several goals:– Increased reliability of the Linac/Booster complex– Control of beam losses– Increased proton flux

• Main challenge: keep beam losses constant while increasing the protons on target– Beam loss limits are set at levels for personnel safety

(ALARA) and equipment serviceability

WBS L3 FY14 FY15 FY16 FY17 FY18+ Total by WBS Deliverables1.0 Management 0.5 0.5 0.5 0.5 0.5 2.51.1.1 200 MHz RF 2.3 3.2 8.1 4.4 7.3 25.3 Reliability1.1.2 Linac Acceleraror Physics 0.5 0.3 0.3 0.3 0.3 1.7 Loss control, proton flux1.1.5 Linac Utilities 0.4 0.4 0.8 Reliability1.2.1 Booster RF 5.6 6 4.1 10 5.3 31 15 Hz pulsing capability1.2.2 Booster Accelerator Physics 0.9 1.2 1 0.8 0.6 4.5 Loss control, proton flux1.2.3 Booster Instrumentation 0.6 0.3 0.9 Loss control, proton flux1.2.5 Booster Utilities 0.2 0.1 0.3 ReliabilityTotal by Fiscal Year 11 12 14 16 14 67

PIP profile

• Notes:• Values are $M TPC including M&S, SWF, and indirects.• Schedule is matched to the funding profile as well as it is known - though some long-lead items are

not far from technically limited.• FY14 is based on formal budget numbers.• FY15 and FY16 are based on preliminary budget guidance.• FY17 and FY18+ are base on previous funding profiles updated for the above guidance (a fully

updated profile has not been produced).


critical path to 15 Hz rf pulsing critical path to 15 Hz beam and flux

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Linac Modulators – From tube based to solid state


9-cell construction

IGBT, Snubber, and Main Storage Capacitor

IGBT

Voltage Transients Test

The Linac DTL 7835 tube modulator is ~45 years old and is increasingly difficult to maintain. Rebuild and replace (old or obsolete parts) was considered but a fully modern system was decided.

Designs being considered: In house IGBT (EE/PS dept)SLAC – Marx generator

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Linac 200 MHz Power Systems 7835 triode

• Burle 7835 triode RF power amplifier tubes for DTL: Consume 8 per year (~250k$ each new)– High vulnerability: poor lifetime, problems with supplier

• This has been a concern for many years for FNAL and other laboratories. After considering several options which looked at cost, labor, schedules and risk, a plan was developed and approved by laboratory management.

1. Inventory buildup: a 4-year supply of tubes2. Design and build a new solid state modulator (keep 7835)3. Replace tube systems in driver with Solid State when

possible4. Investigate 7835 replacement


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Tube replacement


The purchase of a 200 MHz Klystron has just been completed. The device will arrive in FY15 and then tested. This will be the first of its kind and will need to be fully tested before proceeding.

Some key specs:5 MW Single Beam Klystron450µs pulseHorizontal tube~19 feet (floor space issues)

Present78357835 socket

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Booster RF cavities

July 1970 Flatbed semi delivering Booster RF cavity pair

Cavities built by GE


Booster rf cavities• Booster has 22 slots for rf cavities• We can not run (4.3e12) beam with fewer than 17

cavities.• We have 19 cavities on hand

– At any given time: 17 are installed, 2 are out for repair– each cavity requires 3 tuners. Tuners require 3 weeks to

rebuild during the 10-week refurbishment process. • Cavity #20 is the old 1st prototype cavity. It presently

has no tuners and thus can not be used. Cavity itself is being repaired.

• We are planning to procure 10 new prototype tuners (enough for 3 cavities)– delivery date is not determined since some ferrite did not

meet our requirements


Booster PIP - Refurbishment of 40 year old cavities (facelift)


Cavity Removal

Cool-downRemove Tuners

Rebuild - Cones & TunersRebuild Stems/Flanges

Re-AssembleTesting

Weeks0 10

Cavity Removal - Stripping Tuners Rebuild Rebuild and Test


Booster PIP - Cavity Refurbishment Timeline

Refurbishment: “Fun” facts and beyond• All cavities in tunnel need to be refurbished before higher rep

rate (15 Hz) is possible• After refurbishment is completed – higher flux will require time• After refurbishment is completed – the cavities will still be OLD• There is likely to be failures as cavities are run harder• Even if we have 20 cavities installed in the ring, this leaves us

with no spares.• The plan is to procure 3 more cavities in FY16,17

– same type as present cavities– larger bore– install 2 in ring as hot spares


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Summary

• Operational excellence

• High-power targetry

• PIP

• Fermilab is ready for Intensity Frontier investments


Accelerator Operations and PIP

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