# Presentation: 682592

## Proton Upgrades at FermilabRobert ZwaskaFermilabSept. 16, 2006Long Baseline Study Update

## Introduction

- Potential neutrino experiments at Fermilab, soon: Minerva and NOvA
- NOvA requires proton exposure 5-10x that of MINOS
- Additionally, studies are always underway on how to use many, many protons
- Outline
- Current Fermilab Accelerator Complex
- Provides protons for antiproton and neutrino production
- About 250 kW (total) @ 120 GeV
- Programs to improve proton beam power
- Proton Plan  underway
- Super NuMI  in planning
- HINS (proton driver)  in R&D
- Projections: power and timelines
- Neutrino line notes

## Slide 3

## The Main Injector Today

**(Double) 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 ≥ 1.4 s + batches/15

**NuMI**

## 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 ~ 1⁄2 hour)
-  Peak intensity of 3×1013 ppp on the NuMI target

## 
Slip stacking to NuMI in the Main Injector will gradually increase  NuMI intensity to 3.7x1013 protons to NuMI per 2.2 second cycle or about 3x1020 p/yr. (~320 kW)

This will increase by ~30% as protons currently used for pbar production become available. (430 kW)

The Booster rep. rate and efficiency must increase to accommodate this

- Slip stacking to NuMI in the Main Injector will gradually increase  NuMI intensity to 3.7x1013 protons to NuMI per 2.2 second cycle or about 3x1020 p/yr. (~320 kW)
- This will increase by ~30% as protons currently used for pbar production become available. (430 kW)
- The Booster rep. rate and efficiency must increase to accommodate this

## Slide 7

## What the Booster Can Do

- Booster can inject > 9x1012 protons
- Extract as much as 6.6x1012
- At 15 Hz: 36 x 1016 /hr.
- Ultimate Booster Throughput?
- Losses are enormous
- 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

## Limits to Proton Intensity

- Total proton rate from Proton Source (Linac+Booster):
- 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
- Current performance: near 1017 protons/hour recently
- Total protons accelerated in Main Injector:
- Maximum Main Injector load
- Six “slots” for booster batches (3E13)
- Up to ~11 with slip stacking (4-5E13)
- Possible RF stability limitations (under study)
- Cycle time:
- 1.4s + loading time (1/15s per booster batch)

## Prototype in progress
Fabricated and assembled
Testing in Progress
System to be installed 08-09

- Prototype in progress
- Fabricated and assembled
- Testing in Progress
- System to be installed 08-09

- Stronger fields
- More poles
- Faster slew rates
- Major part of Booster upgrades

## Slip-stacking

**Merge two booster batches through RF manipulations**

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

**K. Seiya et. al., PAC2003/5**

## Main Injector Loading

- Present NuMI operation (“2+5”):
- Two batches slip stacked for antiproton production.
- Five more batches loaded for NuMI
- All batches accelerated together.
- Ultimate NuMI operation (“2+9”):
- 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 nine for NuMI.

## SNuMI (Super-NuMI)

- Evolving set of upgrades that take advantage of the present accelerator complex
- Tevatron will be shutdown end of 2009
- (LHC willing)
- No new rings
- Many new devices/tunnels
- Phase I: Recycler Ring: 700 kW
- Allows shorter repetition time
- In active planning
- Phase II: Accumulator Ring: 1.2 MW
- Allows higher intensity
- Under consideration

## SNuMI Stage 1: 700 kWRecycler 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 (5×1012 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
- 4.3×1012 p/batch, 95% slip-stacking efficiency
- 4.9×1013 ppp at 120 GeV every 1.333 s  700 kW

## Sample Timeline

- 0.0 s

- 0.2

- 0.4

- 0.6

- 0.8

- 1.0

- 1.2

- 1.4

- 1.6 s

***Booster***

***Recycler***

- Injection Orbit

- Slipping Orbit

***Main Injector***

*Previous Cycle*

*Next Cycle*

***To NuMI***

## SNuMI 700 kW organization

**Engineering Support**
- R. Reilly

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

**Main Injector**
- I. Kourbanis

-  Additional RF cavities

## Recycler Modifications

-  **Take anti-proton specific devices out**
-  **Build new transfer lines**
-  direct injection into RR
-  new extraction line at RR-30
-  rework RR-30 straight section
-  **Build 5 new kickers**
-  **53 MHz RF system for Recycler**

**Injection line from MI-8 to RR**

**Extraction line in the RR-30 section**

## Elements of the 700 kW Upgrade

- Transfer lines (2)
- Kickers (many)
- Injection(twice), extraction, abort, cleaning
- Recycler 53 MHz RF System
- 300 kV, low R/Q design
- Recycler instrumentation
- BPMs, dampers
- Main Injector ramp time (power supplies)
- Beam Loss Control
- Beam: same intensity as Proton Plan, but comes every 1.333 s, instead of 2.2 s
- Fallback: slip-stacking is expected to be made operational by the Proton Plan
- If slip-stacking is untenable, this upgrade still provides 30% increased beam power through repetition rate and may be able to support other stacking methods

## SNuMI stage 2:  1.2 MWMomentum 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
- Booster must be able to run at 15 Hz
-  Accumulator used for momentum stacking
-  momentum stack 3 Booster batches (4.6×1012 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
-  8.2×1013 ppp in MI every 1.333 s  1.2 MW
- Requires RF upgrade

## Momentum Stacking

- Beam is injected, accelerated, and debunched
- Multiple injections can be brought together
- Different momentum beams separated horizontally
- Beam is accumulated until the momentum aperture of the Main Injector is reached
- 4 injections shown – 3 planned for SNuMI

## Accumulator transfer lines

-  The Booster is connected to the Accumulator via a re-built AP4 Line
-  AP4 must cross underneath the Debuncher and rise to the same elevation as the accumulator
-  The Accumulator is connected to MI-8 line for SNUMI injection via the new AP5 Line
-  The AP5 line must drop ~13’ during the bend to reach the MI-8 elevation
-  Started on conceptual design of AP4 and AP5

- Booster

- To Main Injector

## SNuMI scenarios

|  | Recycler without slip stacking | Recycler with slip stacking | Accumulator momentum stacking |
| --- | --- | --- | --- |
| Booster batch intensity | 4.7E12 | 4.3E12 | 4.6E12 |
| No. Booster batches | 6 | 12 | 18 |
| Booster average rep rate (Hz) | 6 | 10.5 | 15 |
| MI cycle time (s) | 1.333 | 1.333 | 1.333 |
| MI intensity (ppp) | 2.8E13 | 4.9E13 | 8.3E13 |
| Beam power to NuMI (kW) | 400 | 700 | 1200 |
| Protons/hr | 7.6E16 | 1.3E17 | 2.2E17 |

## 8 GeV SC Linaca.k.a. Proton Drivera.k.a. High Intensity Neutrino Source (HINS)

- New* idea incorporating concepts from the ILC, the Spallation Neutron Source, RIA and APT.
- Copy SNS, RIA, and J-PARC 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
- 150x1012 protons per cycle
-  Small emittances => Small losses in Main Injector
-  Minimum (1.5 sec) cycle time (or less)
- 	* ***The 8 GeV Linac concept actually originated with Vinod Bharadwaj and Bob Noble in   ******	******1994,when it made no sense because the SCRF gradients weren’t there. Revived and ******	******expanded by G.W.Foster in 2004***

## 80 % of the Production Cost

- β=1

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- Modulator

- 36 Cavites / Klystron

**ILC LINAC**

*8 Klystrons*
*288 Cavities in 36 Cryomodules *

- 1300 MHz  β=1

**β****<1**** ILC LINAC**

*2 Klystrons*
*96 Elliptical Cavities*
*12 Cryomodules** *

- 1300 MHz     0.1-1.2 GeV

- β=1

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- β=1

- Modulator

- β=1

- β=1

- β=1

- β=1

- Modulator

- 10 MW
- ILC
- Multi-Beam
- Klystrons

- 48 Cavites / Klystron

- β=.81

- Modulator

- β=.81

- β=.81

- β=.81

- β=.81

- β=.81

- 8 Cavites / Cryomodule

**0.5 MW Initial **
**8 GeV Linac**

- 11  Klystrons  (2 types)
- 449 Cavities
- 51  Cryomodules

**“****PULSED RIA”**
- Front End Linac
- 325 MHz
- 0-110 MeV

- H-

- RFQ

- MEBT

- RTSR

- SSR

- DSR

- Single
- 3 MW
- JPARC
- Klystron

- Multi-Cavity Fanout at 10 - 50 kW/cavity
- Phase and Amplitude Control w/ Ferrite Tuners

- DSR

- Modulator

**10 MW**
**ILC**
**Klystrons**

## 325 MHz Front Enda.k.a. One Klystron Linac

- 10 kV

- 110 kV

**MODULATOR:**  FNAL/TTF Reconfigurable for 1,2 or 3 msec beam pulse

**Single **
**Klystron**
**325MHz**
**3 MW**

- Cables to
-  Tunnel

- Fast Ferrite
- Isolated I/Q Modulators

- RF Couplers

**600kW**

**40 kW**
**max**

**120 kW**
**max**

**10kV**

- Room Temperature
- Copper Cavities (16+2)

**Radio Frequency**
**Quadrupole**

**Cryomodule #1-2             **
**SSR1 (18)**

**Cryomodule #3-4 SSR2 (22)**

**60 kW**
**max**

- 325 MHz Front Enda.k.a. One Klystron Linac

## Proton Math

- Current complex
- No Improvements
- Shared Beam
- NuMI Alone
- Proton Plan
- Increase Beam Intensity
- Shared Beam
- NuMI Alone
- SNuMI – Recycler
- Reduce Cycle Time
- SNuMI – Accumulator
- Increase Beam Intensity
- HINS
- Increase Beam Intensity

- Protons ÷ 	Cycle Time =	Power
- 25 x 1012	2.4 s	200 kW
- 30 x 1012	2 s	280 kW
- 37 x 1012	2.2 s	320 kW
- 49 x 1012	2.2 s	430 kW
- 49 x 1012	1.33 s	700 kW
- 83 x 1012	1.33 s	1200 kW
- 150 x 1012	1.33 s	2200 kW

## Rough Proton Power Projections

- Proton plan (in progress)
- Ramp to a capacity of 430 kW in 2009
- SNuMI Recycler/Accumulator upgrades (in design – not approved yet)
- Long shutdowns in 2010 & 2011
- Ramp to 1.2 MW (700 kW) in 2013 (2012)
- High Intensity Neutrino Source (under consideration / R&D)
- 2+ MW sometime in the future

*Note: ~ 1.7**×10**7** s/yr  (effective, at peak power)*

- FERMILAB-BEAMS-DOC-2393

## NuMI Line Capabilities 

- Proton line: beam losses and repetition rate
- Targetry: survival
- Horns: survival
- Note: downtime due to target hall components has been a significant limit on NuMI throughput
- Cooling and survival of other components
- Target hall shielding
- Decay Pipe and windows
- Hadron absorber
- Instrumentation
- Bottom line, so far: 700 kW is not to difficult; greater power will take effort

## Shorter Cycle for NuMI Beamline

- From 1.9 1.33 second rep-rate
- Replace some magnets (QQM 3Q120 Quads)
**25-30 year old magnets  **
**Coils do not have direct cooling.**
**Limited number of spares**
- Build 6 new quadrupole
-  QQB design
- Internal Coil Cooling
- Fewer turns, higher field/amp
- More robust

## Medium Energy Target

- Medium Energy Fin design:
-    Does not need to fit into the horn
-    Graphite fins clamped with cooling plates
-    Provides more water cooling
-    Same graphite as the LE target

## Target Design for yet higher power

- Provides an integrity of the target core and keeps it even in the case of thermo-mechanical or radiation damages of some segments
- Prevents a direct contact of the cooling water with the heated surface of graphite
- Provides a good thermal contact between graphite and metal pipe

- Encapsulation of graphite cylinders (segments) with a prestress of about 10 MPa into stainless steel or aluminum thin-walled pipe:

- Suitable for higher beam power (maybe even 2 MW)
-      but  ~10% fewer neutrinos / POT

- Annular
-  channel
-  for water
-  cooling

## Target Pile Temperature

- 340 F

- Preliminary Calculation
- (from A. Stefanik)
- Uses 2D approximation
- Overestimates temperature rise for present 200 kW ops.
- For 800 kW find 340 F in the steel shielding

- Most of energy deposition is in the first ~1 inch of the shielding
- Add ~1 inch thick water cooled plates for 1.2 MW operations?

## Lowering the primary proton energy ?

- D. Wolff

- Some ideas for neutrino beams have lower primary energy
-  MI Cycle has some irreducible time

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

## Proton Energy Scaling

- Some ideas for neutrino beams have lower primary energy
- Reducing proton beam energy does not results in an equal reduction in cycle time
- Worst for upgrades where Booster is heavily utilized
- Neutrino beams based on lower-energy protons will have lower beam power

- HINS

- SNuMI – Accum.

- SNuMI – Recyc.

- Prot. Plan

- Current

- Sawtooth

## Summary

- Fermilab proton complex can be upgraded to produce a Neutrino Superbeam
- 270 kW peak (170 kW ave.) available today
- 430 kW upgrades are in progress
- Proton Plan → E. Prebys *et al.*
- 700 kW & 1.2 MW upgrades are under study (likely if NOA)
- SNuMI → A. Marchionni (N. Grossman)* et al.*
- ≥ 2 MW beams are under consideration – active R&D
- HINS → G. Appolinari* et al.*
- The upgrades are technically feasible for the accelerators
- Limitations are resources and the capacity of the NuMI (or future) line