Status of the Accelerator Complex Status of the Accelerator Complex - - PowerPoint PPT Presentation

Status of the Accelerator Complex Status of the Accelerator Complex

Ioanis Kourbanis Main Injector Department Fermilab Users’ Meeting June 2, 2010

Overview Overview

• Summer 09 shutdown.
• Proton Source performance and Issues.
• Main Injector high power operation and NuMI.
• Collider Run Plan and Performance.

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Summer 09 shutdown Summer 09 shutdown

• Successfully completed a 12 week summer shutdown.
• Removed the berm at two MI locations (MI-10, MI-40) in
• rder to install penetrations required for NOvA running.
• Seven gap clearing kickers were installed in MI that can become
• peration al after this coming shutdown.
• The rest of the Booster corrector magnets were installed.
• Extensive TeV repairs were performed.
• 8 housed were warmed at room temperature to fix vacuum leaks
• 88 TeV magnets were unrolled or moved.
• Pbar fixed a couple of magnets and installed new 4-8GHz

kickers in the Accumulator.

• NuMI fixed horn 2 water leak, replaced target and the

hadron monitor.

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MI Penetrations MI Penetrations

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Kicker penetrations Penetrations for kicker cooling MI-14 Service Building

MI-40 MI-10

MI Tunnel Penetrations MI Tunnel Penetrations

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Recycler MI Magnets at MI-10 covered with lead blankets for personnel protection Recycler magnets MI penetrations

MI MI-40 Gap Clearing Kickers 40 Gap Clearing Kickers

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Proton Source Performance Proton Source Performance

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MISSING RF STATION

• For pbar stacking and NuMI we

need 5Hz and 7.7E16 P/h.

• RF and beam losses is limiting the

rep rate and the total protons per hour.

• Had to reduce the rep rate while

running without spare rf station.

• Problems with the proton source

affected both the protons per hour and the beam quality out of Booster.

• We have started to see the effect of

the Booster correctors.

• More stable conditions for

tuning

• Better working point
• For NOvA we will need 9Hz rep

rate and 1.4E7P/h.

Booster Neutrino Beam Booster Neutrino Beam

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H- Source Problems Increased rep rate No spare Booster RF station

Fermilab Fermilab Pre Pre-Injectors Injectors

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• Two Cockroft-Walton pre-injectors each with a magnetron H- source.
• Only one source and one Cockcroft-Walton operational at any one time.
• We have been operating with one pre-Injector for almost a year.

I- H-

I- Source Problems Source Problems

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• Had to build a new accelerating

column.

• Problems with die off of sources

after that.

• Spend almost a year without it.
• It now up and running (run with it

the last 21/2 months)

H- Source Problems Source Problems

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• H- source has been un-stable since start-up
• The source has been taken out and rebuilt

twice.

• The ion pump has been replaced
• Improved regulation
• It is running better since March

Future Source Future Source

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• Replace the Cockcroft-Walton with a 200MHz RFQ.
• Replace the present magnetron source with a new one with a circular aperture.
• Similar to the BNL current per-accelerator

Booster RF Booster RF

• Booster is currently RF limited.
• We are still using the original Booster cavities.
• Currently we have one of the spare RF cavities installed in the

tunnel as a “hot spare” (cavity 19).

• A ceramic leak on cavity 19 forced us to have no “hot spare” for

almost 3 months.

• We are working on improving the reliability of the Booster RF

cavities with the Solid State Upgrade.

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• History of the Booster rf
• voltage. The voltage varies

depending how many rf stations are ON.

Booster RF Cavities Booster RF Cavities

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• Booster rf station with Solid State Upgrade.

Only the final power tube is in the tunnel.

• Plan to upgrade the rest of the 16 Booster

stations.

• Original Booster rf station. The whole driver

section of the final tetrode is in the tunnel. It includes 14 parallel connected tetrodes with water cooling.

Power tetrodes

MI Beam Power MI Beam Power

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• We have achieved 95% of the design MI power at 120 GeV.
• Losses in MI are currently preventing us of achieving 400KW.
• To address the losses we need the clearing gap kickers to become
• perational.
• MI uptime is 95%.
• RF Cavity water leaks are a source of concern.

MI Beam Power from 08/2008-04/09

GOAL

Beam to Beam to NuMI NuMI

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Switched to SS for NuMI Horn 1 replacement Horn 2 replacement

• Have delivered more that 2.2E20 protons this

year and more than 1E21P so far!

• No component failures in the NuMI beam line

and better MI performance.

MI RF water leaks MI RF water leaks

• MI is using the old Main Ring RF cavities.
• The driver section of all the MI cavities has been replaced

with solid state drivers (Solid State Upgrade) greatly increasing the reliability.

• Lately we dealing with more and more water leaks in the RF

cavities.

• For the first time in MI we had to take a cavity out of the

tunnel in order to replace a water leak.

• One of the spare MI cavities that has been re-furbished for NOvA

replaced the leaking cavity.

• We plan to proactively address the cavity cooling problems.
• We are working on a new RF cavity prototype for MI

(Project X).

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MI RF Cavity water leak MI RF Cavity water leak

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Cavity water leak

MI Spare Cavity refurbished for NOvA operation

Collider Run Plan Collider Run Plan

• Emphasis is placed on optimizing Integrated

Luminosity.

• All major upgrades have been completed
• Complex is more stable, conditions are more reproducible.
• Use operational model based on recent data to

model the Accelerator performance and find the

• ptimum Pbar initial conditions for maximizing

integrated Luminosity.

• We are working on 3 major improvements
• Maximize Pbar production
• Reduction of the time we spend in HEP shot set-up
• Increase of the proton Brightness

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Response of the model Response of the model

10 20 30 40 50 60 70 80 90 100 200 300 400 500 600 700 Number Of Pbars (Stash size) E10

Intergrated lum. pb-1

Driven By Number of Pbars Driven By Pbars/luminosity lifetime & Pbar Production Rate

• 30 e10/hr Pbar production rate
• 20 e10/hr Pbar production rate

Driven By Pbar Production rate and Luminosity lifetime Driven By Collider Shot Setup Time

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Maximizing Pbar Production Maximizing Pbar Production

24 48 72 96 120 144 168 2005 2009 Hours per week Downtime Hours Study Hours Set-up Hours Stacking Hours

15% 1% Items addressed

• Reduced Shot setup time
• Optimize number of stacking cycles
• Increased Proton on Target

Along with a long list of machine improvements

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• Maximize Pbar production
• Shorting Pbar transfer to Recycler (maximizing

effective stacking rate) – TLG modification – Reducing interruption to stacking

» Interruption to stack was ~1 hour a 1.5 years ago now it 15 sec

– Improving Recycler Lifetime

» Adjusted the incoming beam parameter to maximize cooling efficiency of the machine

Shot Setup Time Reduction Shot Setup Time Reduction

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Optimizing Proton Brightness Optimizing Proton Brightness

• Done by scraping the Proton halo in the Main Injector at 8 GeV
• Improved Initial Luminosity ~3-4%
• Transfer/Acceleration efficiency improvement
• Improves Tevatron dynamic aperture of the machine, reduced

quenching

• Defined as:

Bunch Intensity/ ( Avg. Transverse Emittance X Longitudinal emittance)

y = -0.0011x2 + 1.2533x y = -0.0011x2 + 1.2996x 150 200 250 300 350 400 100 200 300 400 500 pre scraping stores Post scrape Store

• Poly. (pre scraping

stores)

• Poly. (Post scrape

Store)

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Pbars E10 Instantaneous Luminosity E30

Effects of the Source problems Effects of the Source problems

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Results to the improvements Results to the improvements

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7.5%

Sum of improvements made to the complex we see 7.5% improvement to initial luminosity for the same number of protons and pbars used

Record initial luminosity

TeV TeV Reliability Reliability

Year ar Store

• res

Norm rmal al Term rmin inat ations ions %Norm rmal l Term rmin inat ations ions Avg Store re Hrs/Week eek (out utside ide of plann nned ed shut hutdow

• wns

ns)

2003 186 55 30%

• FY04

162 106 65% 100 FY05 211 145 69% 110 FY06 163 101 62% 100 FY07 235 187 80% 110 FY08 304 242 80% 106 FY09 293 253 86% 108 FY10 272 234 86% 124

Improving Reliability

Collider Performance Collider Performance

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• Integrated Luminosity

above the red line.

• Averaging 58 1/pb per

week.

1 2 3 4 5 6 7 8 9 10 11 12 13

Luminosity Projection through FY11 Luminosity Projection through FY11

FY11 start Real data for FY02-FY09 12 fb-1 10 fb-1

Highest Int. Lum Lowest Int. Lum

FY10 start

Integrated luminosity (fb-1)

The green line assumes the same rate for delivered luminosity as in FY09, 50 pb-1/week

Summary Summary

• Successfully completed a 12 week long shutdown.
• Finished the installation of the Booster correctors.
• Finished the MI penetrations for NOvA and installed the

Gap Clearing Kickers.

• Very good overall performance of the accelerator

complex despite problems with aging systems.

• Record beam delivered to NuMI target.
• Record integrated and initial luminosity for Collider.
• We are developing a plan to upgrade our proton

source in order to meet the increasing proton demands.

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