Fermilab Protons Robert Zwaska Fermilab June 27, 2006 Long Baseline Study Workshop

1
Fermilab ProtonsRobert ZwaskaFermilabJune
27, 2006Long Baseline Study Workshop
2
Introduction

• Current Fermilab Accelerator Complex
• Provides protons for antiproton and neutrino
  production
• About 250 kW (total) _at_ 120 GeV
• Programs to improve proton beam power
• Proton Plan ? underway
• Super NuMI ? in planning
• HINS (proton driver) ? in RD
• Projections power and timelines

3
Making Neutrino Beams

• Two operating neutrino 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
4
(No Transcript)
5
The Main Injector Today

• 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 _at_ 15
  Hz
• 4-5 1012 protons per Booster batch
• Total cycle time 1.4 s batches/15

Booster
NuMI
Batch 1 (PBar)
Batch 2
Batch 6
Main Injector
Batch 3
Batch 5
Batch 4
6
Past-Year NuMI Running

• Average power of 165 kW previous to the shutdown
• Maximum beam power of 270 kW down the NuMI line
  (stably for ½ hour)
• Peak intensity of 31013 ppp on the NuMI target

300
200
7
Proton Plan

• The implementation of slip stacking to NuMI in
  the Main Injector will gradually increase NuMI
  intensity to 4-5x1013 protons to NuMI per 2.2
  second cycle or about 3.5x1020 p/yr. (400 kW)
• This will increase by 20 as protons currently
  used for pbar production become available.
• The Booster rep. rate and efficiently must
  increase to accommodate this, and it is hoped
  that there will be enough excess capacity to
  continue to operate the BNB at the 2x1020 p/yr
  level throughout this period.

8
What the Booster Can Do

• Booster can inject gt 9x1012 protons
• Extract as much as 6.6x1012
• At 15 Hz 36 x 1016 /hr.
• Ultimate Booster Throughput?
• Losses are enormous, and not reliable
  cycle-to-cycle
• About 1200 J / cycle
• At 1 W/m 1 x 1016 /hr
• Running this way would maximize the number of
  protons per-batch, but severely limit the
  integrated number of protons delivered
• Booster does not run this way

7.E12
4.6E12
9
Limits to Proton Intensity

• Total proton rate from Proton Source
  (LinacBooster)
• Booster batch size
• 4-5E12 protons/batch
• Booster repetition rate
• 15 Hz instantaneous
• Prior to shutdown 7.5Hz average (pulsed
  components)
• Beam loss
• Damage and/or activation of Booster components
• Above ground radiation
• Total protons accelerated in Main Injector
• Maximum main injector load
• Six slots for booster batches (3E13)
• Up to 11 with slip stacking (4.5-5.5E13)
• Possible RF stability limitations (under study)
• Cycle time
• 1.4s loading time (1/15s per booster batch)

10
Slip-stacking

• Merge two booster batches through RF
  manipulations

K. Seiya et. al., PAC2003

• Doubles the azimuthal charge in the Main
  Injector
• Booster loading time is doubled

11
Main Injector Loading

• Initial NuMI operation (25)
• Two batches slip stacked for antiproton
  production.
• Five more batches loaded for NuMI
• All will be accelerated together.
• This is the current standard operation.
• Ultimate NuMI operation (29)
• 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.
• ? 440 kW of protons

12
(No Transcript)
13
MI-8 Dump Line
Relocated Septum
Dump
New Dump Line
14
MI-8 Collimator
Note marble cladding
15
Main injector large aperture quads
16
Booster Corrector Upgrades

• Prototype in progress
• Coils and cores complete
• Assembly beginning
• Ready for test beginning of June

• Stronger fields
• More poles
• Faster slew rates

17
SNuMI Stage 1 700 kWRecycler as an 8 GeV Proton
Pre-injector

• After the Collider program is terminated, we can
  use the Recycler as a proton pre-injector
• Use the Recycler to accumulate protons from the
  Booster while MI is running
• Save 0.4 s for each 6 Booster batches injected
• 6 batches (51012 p/batch) at 120 GeV every 1.333
  s ? 430 kW
• Recycler momentum aperture is large enough to
  allow slip-stacking operation in Recycler, for up
  to 12 Booster batches injected
• 4.31012 p/batch, 95 slip-stacking efficiency
• 4.91013 ppp at 120 GeV every 1.333 s ? 700 kW

18
SNuMI stage 2 1.2 MWMomentum stacking in the
Accumulator

• After the Collider program is terminated, we can
  also use the Accumulator as a proton ring
• Transfer beam from Booster to Accumulator
• Accumulator used for momentum stacking
• momentum stack 3 Booster batches (4.61012
  p/batch) every 200 ms
• no need to cog in the Booster when injecting
  into the Accumulator
• longitudinal emittance dilution of 20 instead
  of a factor 3 like in slip-stacking
• Box Car stack in the Recycler
• load in a new Accumulator batch every 200 ms
• place 6 Accumulator batches sequentially around
  the Recycler
• Load the Main Injector in a single turn
• 8.21013 ppp in MI every 1.333 s ? 1.2 MW

19
Momentum Stacking
20
SNuMI scenarios
21
SNuMI 700 kW organization
Main Injector I. Kourbanis

• Additional RF cavities

Engineering Support R. Reilly

• NuMI Target Hall and
• components (2 FTE)
• Proton delivery (1 FTE)
• Support from PPD on FEA

22
Introduction 8 GeV SC Linac

• New idea incorporating concepts from the ILC,
  the Spallation Neutron Source, RIA and APT.
• Copy SNS, RIA, and JPARC Linac design up to 1.3
  GeV
• Use ILC Cryomodules from 1.3 - 8 GeV
• H- Injection at 8 GeV in Main Injector
• Super Beams in Fermilab Main Injector
• 2 MW Beam power at both 8 GeV and 120 GeV
• Small emittances gt Small losses in Main
  Injector
• Minimum (1.5 sec) cycle time (or less)
• MI Beam Power Independent of Beam Energy
  flexible program
• The 8 GeV Linac concept actually originated
  with Vinod Bharadwaj and Bob Noble in
  1994,when it made no sense because the SCRF
  gradients werent there. Revived and expanded by
  G.W.Foster in 2004

23
8 GeV Superconducting Linac
Anti- Proton
24
Two Design Points for 8 GeV Linac

• Initial 0.5 MW Linac Beam Power (BASELINE)
• 8.3 mA x 3 msec x 2.5 Hz x 8 GeV 0.5 MW
• 11 Klystrons Required
• Ultimate 2 MW Linac Beam Power
• 25 mA x 1 msec x 10 Hz x 8 GeV 2.0 MW
• 33 Klystrons Required
• Either Option Supports
• 1.5E14 x 0.85 Hz x 120 GeV
• 2.4 MW Beam Power from MI

25
0.5 MW Initial 8 GeV Linac
PULSED RIA Front End Linac 325 MHz 0-110 MeV
Single 3 MW JPARC Klystron
Modulator
Multi-Cavity Fanout at 10 - 50 kW/cavity Phase
and Amplitude Control w/ Ferrite Tuners
11 Klystrons (2 types) 449 Cavities 51
Cryomodules
H-
RFQ
MEBT
RTSR
SSR
DSR
DSR
ßlt1 ILC LINAC
10 MW ILC Multi-Beam Klystrons
Modulator
1300 MHz 0.1-1.2 GeV
48 Cavites / Klystron
2 Klystrons 96 Elliptical Cavities 12 Cryomodules
ß.81
ß.81
ß.81
ß.81
ß.81
ß.81
8 Cavites / Cryomodule
8 Klystrons 288 Cavities in 36 Cryomodules
ILC LINAC
1300 MHz ß1
80 of the Production Cost
Modulator
Modulator
Modulator
Modulator
10 MW ILC Klystrons
36 Cavites / Klystron
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
Modulator
Modulator
Modulator
Modulator
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
ß1
26
Front End - Beam Line Layout

• Ion source H-, LEBT 50 keV
• Radio Frequency Quadrupole 4-5 m, 2.5 MeV
• MEBT (2 bunchers, 3 SC sol., chopper) 4 m
• RT TSR section (16 resonators, 16 SC solenoid)
  10 m 10 Mev
• SSR1 section (18 resonators, 18 SC solenoids)
  14 m 30 MeV
• SSR2 section (22 resonators, 12 SC solenoids)
  20 m 90 MeV

Frequency 325 MHz Total length 55 m Limited by
Meson Building
SSR1 (b0.22)
SSR2 (b0.4)
RT -CHSR
MEBT
RFQ
IS
2.5
0.050
90
10
W (MeV)
30
27
325 MHz Front Endaka One Klystron Linac
MODULATOR FNAL/TTF Reconfigurable for 1,2 or 3
msec beam pulse
110 kV
10 kV
Single Klystron 325MHz 3 MW
10kV
RF Couplers
40 kW max
120 kW max
60 kW max
600kW
Fast Ferrite Isolated I/Q Modulators
Cables to Tunnel
Room Temperature Copper Cavities (162)
Radio Frequency Quadrupole
Cryomodule 1-2 SSR1 (18)
Cryomodule 3-4 SSR2 (22)
28
Motivation and Timeline

• Motivation Demonstrate key and un-tested
  technologies important to the low-energy
  front-end (ßlt0.4) section of the proposed 8 GeV
  H- Linac
• Timeline Accomplish the RD necessary to
  establish technical credibility and cost basis
  for the Linac front-end by 2010

29
325 MHz 2.5MW Klystron
30
4.5 msec Klystron Pulse Transformer
31
325 MHz Waveguide Circulator
32
HINS Collaborations

• ANL Ongoing
• Beam Dynamics
• Spoke Cavities Processing
• MSU Ongoing
• b0.81 Elliptical Cavities development
• LBL - Starting
• Electron Cloud Effects in MI
• Buncher Cavities
• BNL Under negotiation
• Injection Studies
• Stripping Foil Simulation Engineering
• Laser Beam Profiler

33
Schedule Proton Power Projections
Note 1.7107 s/yr (effective, at peak power)

• Proton plan (in progress)
• Ramp to a capacity of 440 kW in 2009
• SNuMI Recycler/Accumulator upgrades (in design
  not approved yet)
• 1 year shutdown in 2010
• Ramp to 1.3 MW (700 kW) in 2012
• High Intensity Neutrino Source (under
  consideration / RD)
• 2 MW sometime in the future

34
Old Sawtooth Ramp

• This is a poor approximation

35
Lowering the primary proton energy ?

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

D. Wolff

• this is achievable now (conservative)
• Faster ramps possible (with PS upgrades)

36
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

37
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 1.3 MW upgrades are under study (likely
  if NOnA)
• SNuMI ? A. Marchionni et al.
• 2 MW beams are under consideration active RD
• HINS ? G. Appolinari et al.
• Primary proton energy needs to be considered
• Lowering proton energy below 120 GeV always
  reduces the beam power on target
• Lower primary proton energies need to be well
  justified, if requested