# Presentation: 040725

## Overview of BNL’s Accelerator R&D Program 

- Vitaly Yakimenko
- April 18, 2006
- DOE Annual High Energy Physics Program Review
- Brookhaven National Laboratory

## Outline:

- Superconducting Magnet Division (SMD)
*  **Peter Wonder*
- Advanced Accelerator R&D group
-   *Robert Palmer*
- Accelerator Test Facility (ATF)
-  *Vitaly Yakimenko*
- Accelerator R&D at C-AD* *

## HEP Superconducting Magnet Program

- ILC Beam Delivery System R&D
- High Field Magnet R&D
- Superconducting Materials Development
- LARP - Magnets

## ILC Final Focus Magnet R&D - FY06/07

- FY06 accomplishments:
- 	Integrated design (beam optics + superconducting magnets) of 14 mrad IR
- 	Successful test of coil with active shielding of external magnetic field
- 	Measured motion of a cold magnet at the sensitivity needed at the ILC IR.

- FY07 plans:  Start 2m prototype magnet, continue beam optics work, continue vibration studies

## High Field Magnet R&D

- Nb3Sn React-and-Wind Common Coil (twin-aperture, 4cm gap) dipole completed and tested.  Reached conductor limit, 10 T.
- React-and-wind can also be used for high temperature superconductor.

- Program terminated due to lack of funding

## Superconducting Materials Development

- Close collaboration with Materials Science Dept. and industry: materials expertise + magnet expertise
- Low Temperature Superconductor (LTS) R&D
- Nb3Sn conductor development
- Leading LARP three-lab effort on Nb3Sn
- MgB2 wire development
- High Temperature Superconductor (HTS) R&D
- Bi-2223 tape and 2nd –generation YBCO tapes
- Strain sensitivity: Nb3Sn ≈ HTS  Nb3Sn experience & equipment useful with HTS.

## BNL LARP Magnet Program

-  GOAL:  test Nb3Sn long racetrack coils and support structure  input to LARP quadrupole design
-  Collaboration: FNAL (manager) + LBNL ( support structure) + BNL (coils)
-  STATUS: 30 cm racetrack coil + support structure ready to test
-  Transfer of “wind and react” technology from LBNL to BNL
-  PLANS:
-  test 3.6 m coils and support structure – December 2006
-  check effect of lengthening on coil, support structure
-  test additional 3.6 m coil – September 2007
-  check quad coil construction methods

## Summary

- Magnet program well aligned with the National goals: ILC, LARP. These elements receive direct programmatic funding.
- Distinguishing features of the program are:
- Direct wind technique
- HTS development (mostly outside HEP in BES/NP)
- Materials expertise
- React-and-Wind Nb3Sn development
- Full length fabrication and testing
- Base program support continues to be reduced
- High field magnet R&D terminated
- Cable testing terminated

## Advanced Accelerator R&D Group

- Working on
- Neutrino Factory & Muon Collider collaboration (NFMCC):
- Neutrino Factory & Muon Collider R&D
- Liquid Target Experiment MERIT
- Non NFMCC Advanced Accelerator work
- Solid Target Radiation Studies
- Fixed Field alternating Gradient (FFAG) Studies

## Advanced Accelerator R&D

## Advanced Accelerator R&D

## Neutrino Factory Design & Simulation (Part of NFMCC)

- Neutrino Factory Design & Simulation (Part of NFMCC)

**Mainly part of International Scoping Study (ISS)**
**Comparison of Schemes **
**Only 201 MHz Study 2A achieves**
- 1021 **mu decays per year goal**
**ISS current leanings:**
**201 MHz frequency ****OLD**
**Proton Energy ** **10 GeV ****NEW**
**5 bunch proton train (0.5 **μ**s sep)**
**to reduce loading and space charge problems ****NEW**

## Liquid Target Experiment MERIT (Part of NFMCC)

**Liquid Target Experiment MERIT (Part of NFMCC)**

**BNL,MIT,CERN,RAL,Princeton,Oak Ridge Collaboration ****Harold Kirk is one of two Spokespersons**
**Will expose mercury Jet to CERN proton beam**
**Probably only practical target at 4 MW**
**BNL oversight of 15 T pulsed magnet acquisition**
**   ****Magnet now at MIT for testing - below right**
**Instrumentation Department building Optics system**
**   ****to observe mercury dispersion by beam**

## Recent progress on MERIT

## Advanced Accelerator R&D

## Targetry R&D budget

- Liquid Target Studies		$50K
-  Engineering Support
- Solid Target Studies		$270K
-       Blip Beam Time
-       Hot Cell usage
-       Instrumentation
-       Materials
-       Horn/Target design
- Graduate Student		$50K
- Travel				$30K
- Total				$400K

- The bulk of the resources  is placed into our materials/irradiation studies.

## Advanced Accelerator R&D

## Advanced Accelerator R&D Summary

## BNL Accelerator Test Facility - ATF 

- The ATF is a proposal-driven, advisory committee reviewed USER FACILITY for long-term R&D into the Physics of Beams.
- The ATF serves the whole community: National Labs, universities, industry and international collaborations.
- ATF contributes to Education in Beam Physics. **(~2 PhD / year)**
- In-house R&D on photoinjectors, lasers, diagnostics, computer control and more **(~3 Phys. Rev. X / year)**
- Support from HEP and BES.

- The ATF features:
**High brightness electron gun **
**75 Mev Linac**
- High power lasers beam-synchronized at the picosec level (**TW level CO2 laser**)
- 4 beam lines + controls

## ATF Statistics

- Run time: ~ 1000 hour / year
- Graduated students: 22
- Current number of experiments: 14
- Staff members: 11, 1 visitor
- Phys Rev X: ~ 3 / year since 1995

## ATF Terawatt CO2 Laser Story (past and present)

- 1995              2000	     2005		2010

**Inverse**
**Cherenkov**
**accelerator**

**IFEL**
**accelerator**

**Thomson**
**X-ray source**

**HGHG**

**STELLA**

**Ion and**
**Proton**
**source**

**Resonant**
**PWA**

**Seeded**
**LWFA**

**LACARA**

**PASER**

- 3 TW

- 300 GW

- 30 GW

- 3 GW

**Nonlinear Thomson**
**scattering**

**EUV source**

## Why we need better emittance 

- To match laser accelerating or FEL beam and electron beam;
- or to transport through small (high frequency) accelerating channel

## Ion generation experiment 

## Monochromatic beams with CO2 laser

- Proton energy spectrum from a structured target. (a) Solid state laser with =1m. (b) CO2  laser with =10m. The CO2 laser produces a much narrower proton spectrum because of the narrower phase space fill.

## Plasma Wakefield experiments at ATF

- Multi-bunch Plasma Wakefield Acceleration at ATF, AE31. Spokepersons T. Katsouleas and P. Muggli, Univ. Southern California.
- Laser Wakefield Acceleration Driven by a CO2 Laser, AE32, Spokesperson W. Kimura, STI Optronics
- Ion Motion in Intense Beam-Driven Plasma Wakefield (UCLA, J. Rosenzweig)
- Plasma density measurement 1016-1019 by Stark broadening

## Beam splitting during compression

- Interaction of the Coherent Synchrotron Radiation (CSR) with the beam itself leads to energy modulation along the beam.
- It produces two distinct beams (due to two stages of compression: chicane and dog-leg) very useful for some experiments at ATF (two beam PWA).
- X band linac section is needed to deliver clean, low energy spread compressed beam to user experiments
- Structure is available, ATF has a spare modulator, SLAC needs $350K to manufacture  X-band klystron for ATF
- Three experimental groups will immediately benefit.

- Chicane

- Dog-leg

- Linac

- Experimental beam line

- Spectrometer

- E

- E

- ~2%

- ~2%

- x-band

## Optical Stochastic Cooling

- It is feasible to cool gold and protons beams at full energy in RHIC and possibly Pb at LHC with multistage optical amplifier.
- Optical parametric amplifier based on CaGeAs was suggested and experimentally tested at ATF
- Bypass experiment with electron beam at ATF
- Will prove lattice control, optical amplifier and adequate diagnostics
- It is similar to previously successful at ATF staged laser accelerator (STELLA and STELLA II) experiments.
- requires dedicated manpower.

## Polarized Positron Source (PPS) summary

- Compton back-scattering based PPS is a backup scheme for ILC and the only choice for CLIC
- We propose Compton-based PPS inside optical cavity of CO2 laser beam and 6 GeV e-beam produced by linac.
- The proposal utilizes commercially available units for laser and accelerator systems.
- The proposal requires high power picoseconds CO2 laser mode of operation developed at ATF. (ATF is the only facility in the world with operational Joule/picosecond CO2 laser system.)
- 3 year laser R&D is needed to verify laser operation in the non standard regime.

## Conclusion

- The experimental program at ATF is strong, broad and relevant to HEP
- It is aimed at near, intermediate and long term accelerator R&D:
- Beam brightness, compression (LCLS)
- Polarized Positron Source (ILC and CLIC)
- Optical Stochastic Cooling (RHIC and LHC upgrade)
- Beam and laser based Plasma Wakefield Accelerators (PWA), ion movement in the PWA (ILC upgrade)
- Laser based accelerators (post ILC)
- Compact, high brightness laser based proton, ion and neutron sources (medical applications, injector, security...)
- ATF plays important role in education of accelerator scientists
- The support and progress of the user experiments is seriously limited by the accelerator staff level

## Accelerator R&D at C-ADfrom V. Litvinenko (non HEP funding)

- High current super-conducting energy recovery linacs (ERL)
- High current super-conducting RF guns
- Generation and transport of ultra-high brightness electron beams in ERLs
- Secondary emission (diamond) photo-cathodes
- High energy electron cooling of ions and protons in collider mode
- Stochastic cooling of bunched beams
- Development of polarized SRF electron gun (with MIT)
- Development of FFAG (fixed-filed alternating-gradient) accelerator lattices for protons and ions
- Development of rapid cycling proton synchrotron for medical applications