NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Primary Beams for Mini-BooNE

&NuMI

18 March, 2002

Mini-BooNE inputs from Craig Moore and Al RussellIncludes NuMI inputs from Bob Ducar, Peter Lucas,

John Johnstone and Alberto Marchionni

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Very Different Primary Energies –but Common Goals

MiniBooNE:Primary Beam Momentum- 8.9 GeV/c from Booster.

Intensity goal - 5x1012 ppp at 5 Hz cycle rate.

Goal: ∫ Protons = 5 x 1020 p/year - An annual flux > than the sum of all previous FNAL Booster operation over 30 yrs.

NuMI:Primary Beam Momentum- 120 GeV/c from Main Injector.

Intensity Goal: to 4x1013 ppp at 1.87 sec. cycle rate.

An annual beam power comparable to the sum of all previous Fermilab fixed target operation.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Mini-BooNE Primary Beam - Overview

Primary Beam Momentum- 8.9 GeV/c Spill length 1.6 microsecondsIntensity - 5x1012 ppp Rep rate 15 Hz (5 Hz Beam) 2x107 seconds/yr

∫ Protons = 5 x 1020 p/yearInvariant Emittance 20 Pi mm.mr – 95% beam envelope

Targeting Parameters:· Target 9 mm diameter cylinder· 99% spot size < 8mm diameter· Targeting angle and beam divergence < 4.6 mr· Position stability < 1 mm

The greatest concern – achieving essential radiation level improvements for Fermilab Booster – discussed in Radiation Protection Session

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Schematic Layout of MiniBooNE Beamline

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Design Process Improvement: MiniBooNE Primary

The most significant design improvement since original design efforts has been a change to much larger aperture dipoles and quads (considerable magnet refurbishing, but use of existing magnets)

Early Design: EPB dipoles (37 mm aperture) and 3Q quads (75 mm)

Upgrade Design: 6-3-120 dipoles (75 mm aperture) and LEP quads (125 mm)

The following figures show an original beam transport envelope plot leading to the early stage aperture upgrade.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Vertical Clearance – 99% EnvelopeBEFORE Improved Apertures

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

MiniBooNE Beam Envelope and Apertures - Horizontal

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Mini-BooNE Beam Monitoring - Electronic Berm

By measuring the difference in two well calibrated intensity monitors at the beginning and end of beamline, can detect losses and abort beam.

If this is done in a failsafe manner, can substitute for some shielding.or other electronic radiation monitoring.

BooNE is looking to measure a 2% loss averaged over several pulses or >6% over 1 pulse.

Significant improvement over previous similar usage at Fermilab

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Other Features – BooNE Primary

·Much standard instrumentation·Multiwire profile SEM monitors ·Beam Loss Monitors·BPM’s (noninteracting position monitors)

·< 0.5 mm resolution for targeting units·Power supply stability upgrades (FNAL standard

packages)·Autotune beam position control – very successful in

several previous uses.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Schedule: BooNE Primary Commissioning

• Beam enclosures complete

• Technical component installation ongoing & well advanced.

• Project initial beam commissioning effort by June ‘02

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)NuMI Primary Beam

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Some NuMI Primary Beam

Parameters

• Highest possible intensity from Main Injector- Near term projection ~ 2.5x1013 protons per pulse, 120

GeV at 1.87 sec. cycle time (Goal to 4x1013 ppp)- Kicker extraction 5 batches each of 1.6 µsec - Simultaneous operation with PBAR stacking

• Targeting parameters- Beam sigma 0.7mm (h) x 1.4mm (v)- No dispersion & minimal divergence at target- Position control ~ 0.25 mm; angle to 70 µrad.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)NuMI Facility(elevation view)

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

• Some significant NuMI primary beam constraints.« Very high primary intensity ~ 80% of Main Injector

capability.« Transport of this intense beam in a tunnel located in the

protected groundwater aquifer region. Effective shielding not a practical option.

« Initial beam transport design constraints imposed by long drift region (430’) from glacial till to pre-target tunnel in mined dolomite.

• Solution accomplished by a rigorous approach for primary beam control involving transport design, power supply stability, instrumentation usage, control algorithms and comprehensive beam permit system.

NuMI Primary Beam Constraints

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Beam Loss Model Geometry

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Beam Loss Limits from MARS14

Calculations

• Results indicate average beam loss fraction limits of 110-4

to 610-3 of the high intensity primary beam flux, dependent on tunnel location. A loss fraction limit of 10-6 of the beam is seen in lined regions of the carrier tunnel. However, in this region geometry constraints preclude direct primary beam loss except for fault modes such as a vacuum pipe collapse or a magnet coil failure.

• Maintaining average beam loss fraction levels at ~ 10-4 or less is also well matched to need for control of component residual activity. Sustained localized beam loss of this level leads to ~ 150 mrem/hr readings on near magnet outside surfaces.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)System for Beam & Beam Loss

Control

• Most important is a well functioning beam transport line« Apertures / optics design enabling clean beam transmission, minimal

sensitivity to normal variations of beam parameters - emittance, momentum spread, bunch rotation, etc.

« Quantitative understanding of Main Injector extracted beam parameters.• Power supply stability

« Design for long term ~ 60ppm for major bends, 200ppm for smaller bends. (One supply at these limits gives < 1 mm change along transport, 0.25mm for targeting.) Pulse to pulse variations are much less.

• Comprehensive loss monitor coverage « Sensitivity to all beam loss modes, redundancy of loss coverage,

continuous checks for loss monitor function, calibrated response and dynamic range for fractional beam loss from 10-5 of the high intensity beam to a full beam loss

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)System for Beam Control (cont)

• Capability for precise and rapid correction of beam position problems due to system drifts« AUTOTUNE beam position control

• Comprehensive alarms and limits monitoring• Comprehensive beam permit system to preclude beam

extraction to NuMI when an identifiable problem exists« Beam test prototyping of hardware ongoing

All of these are patterned after previous successful efforts.

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Characterization of Main Injector Beam Parameters

D. Jensen, G.M. Koizumi, V. Makeev, A. Marchionni FermilabB.C. Choudhary CalTech

Measurements of transverse and longitudinal beam profiles in MI as a function of beam intensity

Additional measurements of momentum spread in P1

Plan for the future

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Bunch length from Resistive Wall

Monitor @flattop

Intensity RF (MV) Bunch half-length

(2) (ns)p/p l (eVs)

1 1012 2.8 0.95 5.6 10-4 0.20

2 1012 2.8 1.15 6.7 10-4 0.29

4 1012 2.8 1.95 1.1 10-3 0.83

Observed variations of ~ 10%

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)Bunch Length during Bunch Rotation

Time (t=0.188 ms)

Aver

age

2 (n

s)

From RTD720

BLMON

2.5 ms

2.5 ms

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Baseline Beam Envelope with Apertures

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Improved Beam Envelope with Apertures

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

Beta & Eta Functions:Projected Design

NuMI

PrimaryBooNE / NuMI

S. Childress (FNAL)

• A significant number of essential improvements to NuMI primary design and planning have been seen over recent months – to address some severe design constraints.

• Efforts are ongoing to incorporate these into the project plan.

• Technical construction funding available Oct.’02. Priority then moves to building systems.

• Major installation ramp up late ’03 when Service Bldg. and tunnel outfitting complete.

• Beam commissioning late ’04 – early ’05.

NuMI Primary Summary