# Presentation: 223631

## Project X Linac

**Giorgio Apollinari**
**Fermilab Accelerator Advisory Committee**
**August 8****th**** - 10****th**** , 2007**

## Outline

**Introduction**
**Description of Project X Linac**
- Beam Line Components and Considerations
- RF Power, Civil and Cryogenics Considerations
**Conclusions**

## Introduction

**An 8 GeV Linac coupled with an upgraded FNAL facilities is required to get above 2 MW at 120 GeV (MI)**
**The 8 GeV Linac idea* incorporates concepts from the ILC, the Spallation Neutron Source and RIA.**
- Copy SNS, RIA, and JPARC Linac design up to 1.3 GeV
- Use ILC-like  Cryomodules (=1 cav.)  from  1.3 - 8 GeV
- H- Injection at 8 GeV in Main Injector
**	***** ***The 8 GeV Linac concept actually originated with Vinod Bharadwaj and Bob Noble in 1994,when it was realized that the MI would benefit from a Linac injector. Gradients of 4-5 Mev/m did not make the proposal cost effective at the time. Idea revived and expanded by GWF in 2004 with the advent of 20-25 MeV/m gradients.*

## ILC LINAC

- 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**

## FY06 start of  HINS (High Intensity Neutrino Source) R&D Program with availability of Neutrino Initiative funds
Establishment of collaborations
Beam dynamic studies in realistic conditions (misalignments, beam correctors, etc.)
Address major R&D Issues
Started full alignment of =1 section with ILC technology
Based on concept of ILC RF Unit: 
9 cavities – 8 cavities/1 quad – 9 cavities 
“Reference” Linac design with 8 ILC RF-Units

**FY06 start of  **_**HINS**_** (High Intensity Neutrino Source) R&D Program with availability of Neutrino Initiative funds**
- Establishment of collaborations
- Beam dynamic studies in realistic conditions (misalignments, beam correctors, etc.)
- Address major R&D Issues
**Started full alignment of ********=1 section with ILC technology**
- Based on concept of ILC RF Unit:
- 9 cavities – 8 cavities/1 quad – 9 cavities
- “Reference” Linac design with 8 ILC RF-Units

- Toward an ILC-Project X Alignment:“Reference” Design

## Emphasis on number of ILC RF units:
8 ILC units with 208 ILC-identical cavities and 24 ILC-identical cryomodules
In addition
ILC-1 section with 63 ILC-identical cavities and 9 ILC-like cryomodules
S-ILC section with 56 ILC-like cavities and 7 ILC-like cryomodules
Compromise on accelerating fields in ILC cavities and presence of S-ILC:
167 ILC-identical cavities operating at 31.5 MeV/m
104 ILC-like cavities operating at 18.3 MeV/m

- Project X: “Reference” design

**Emphasis on number of ILC RF units:**
- 8 ILC units with 208 _ILC-identical_ cavities and 24 _ILC-identical_ cryomodules
- In addition
- ILC-1 section with 63 _ILC-identical_ cavities and 9 _ILC-like_ cryomodules
- S-ILC section with 56 _ILC-like_ cavities and 7 _ILC-like_ cryomodules
**Compromise on accelerating fields in ILC cavities and presence of S-ILC:**
- 167 _ILC-identical_ cavities operating at 31.5 MeV/m
- 104 _ILC-like_ cavities operating at 18.3 MeV/m

## “Reference” design Beam Parameters

- “Reference” design Beam Parameters

## Project X: “8/9” Design

**ILC Preliminary RDR release in February ’07**
- .....
- FNAL Steering Group for accelerator-based HEP program
- Project X proposal (July 07):
**8 GeV Linac as “ILC-identical” as possible.**
- Same beam  parameters
- 9mA with 1 ms long pulse at a rate of 5 HZ
- Same configuration
- ILC cryomodules  for  = 1
- RF distribution and cryogenic distribution for =1, etc.

## Project X: “8/9” Design

**Basic tenets:**
- Use ILC RF units for high energy (>0.9) Linac
- Use ILC cavities (and slightly-modified ILC cryomodules) operated in 8/9 mode (P. Ostroumov – ANL) at intermediate energies
- All cavities operated at ILC parameters
- 31.5 MeV/m, 9 mA, 1 ms, etc.
- Frequency transition (325 MHz to 1300 MHz) at 600 MeV
**At 1.3 GHz, all cavities have ********=1 ILC design operating at 31.5 MeV/m.**

## Tables and pictures worth 1000’s words

## Tables and pictures worth 1000’s words

**ILC-2***: 12 cryomodules, 96 cavities, 12 quads**	**	**2.4 – 5.2 GeV*

**ILC ***: 12 cryomodules, 104 cavities, 4 quads**	**	**5.2 – 8.0 GeV*

- +

- +

**“****ILC-identical” Cavities/Cryomodules:****	****	****305/24**
**“****ILC-like” Cavities/Cryomodules:****	****	****N.A./15**

## Tables and pictures worth 1000’s words

## Why 8/9

- Analytical Field Distribution

- Transit Time Factor

- 3D ILC Cavity Simulation

- TRACK Beam Dynam.

## Is 8/9possible for ILC Cavities ?

- TESLA 1998-20
- Outstanding feature: 8/9 mode is only 0.8 MHz away from fundamental p mode
**Tuning Issue: once ILC cavity is produce, “stretch” it to tune ******** mode to 1.3008 GHz**
**In ILC, +/-300 kHz tuning range**
- 8/9 mode is not within the expected nominal ILC tuning range but should be achievable

## Project X Linac Design

**We propose at least two designs exploiting alignment between Project X and ILC**
- The “Reference” design emphasizes the number of ILC-RF units
- 1.3 GHz from 0.4 GeV to 8 GeV
- S-ILC Cavities
- Operates 40% of ILC-Cavities at 18 MeV/m
- The “8/9” design emphasizes the number of ILC Cavities operated at 31.5 MeV/m
- 1.3 GHz from 0.6 GeV to 8 GeV
- Only =1 ILC-identical cavities (305) operated at 31.5 MeV/m
**Linac Front-End (Webber’s talk)**

## RF Power Considerations and Distribution

**325 MHz Power**
- Will need five 325 MHz, 2.5 MW klystrons for the 0-600 MeV Linac
- Low , beam phase and possible cavities field variations will require use of IQM modulators
- 40 kW ~ 120 kW
- Phase: +/- 45 degree, Amplitude: +/- 1.5 db
- 1 degree/1sec
**1300 MHz Power**
- Planning on ILC Modulator and 10 MW ILC klystron
- Longitudinal dynamics of the non-relativistic H- beam and possible cavities field variations over time (SNS experience) will require use of IQM modulators throughout the Linac with the exception of the final four ILC 9-8-9 RF units
- Need of additional RF simulation/experience on cavities field uniformity to prove the ability to control the RF distribution through LLRF under beam-loading conditions in the in the HE part of the Linac.

## Cryogenic Considerations

**Cryogenic system temperature and pressure levels determined by choice of ILC-style cryomodules**
- ILC section cold mass operates at 2K
- 325 MHz Front End cooled by 2-phase He at 4.5 K
**8 GeV Linac cryogenic system will be similar, in scale, to the Spallation Neutron Source system.**
**Challenges (face by ILC as well):**
- Liquid level control in long strings
- Uncertainty in heat load estimates
- Optimization of capital vs. operating costs
- Protection from over-pressurization due to abnormal operating conditions
- Compliance with engineering standards

## Civil Site Considerations

**Considerable efforts placed on the investigation of site location at the time of the Proton Driver proposal (several constraints on injection into MR or Recycler)**
**No additional evidence suggesting a more suitable location than inside the southern half of the Tevatron Ring**
**Site characterized professionally**
- Wet land impact (120-160 acres)

## SCRF Facilities available at FNAL
Cold String assembly line (MP9)
Cryomodule Assembly Facility (ICB) 
BCP/EP at ANL/FNAL and VTS @ FNAL 
Project X in line with other ILC activities at FNAL 
Project X will contribute to the industrialization of ILC components and SCRF technology:
~300 ILC cavities and ~100 Spoke Resonators
Cavities Companies: AES (ILC), Roark (ILC, HINS)
~40 ILC cryomodules and ~50 ILC quadrupoles
 PHPK (HTS), Meyer Tools (LHC cryomodules and ANL SSR),...
~400 Power Couplers: 
CPI (XFEL-Desy), Ability Engineering (HINS SSR PCs)

- Cold String assembly line (MP9)
- Cryomodule Assembly Facility (ICB)
- BCP/EP at ANL/FNAL and VTS @ FNAL
- Project X in line with other ILC activities at FNAL
**Project X will contribute to the industrialization of ILC components and SCRF technology:**
- ~300 ILC cavities and ~100 Spoke Resonators
- Cavities Companies: AES (ILC), Roark (ILC, HINS)
- ~40 ILC cryomodules and ~50 ILC quadrupoles
-  PHPK (HTS), Meyer Tools (LHC cryomodules and ANL SSR),...
- ~400 Power Couplers:
- CPI (XFEL-Desy), Ability Engineering (HINS SSR PCs)

- Project X Linac at FNAL

## Conclusions

**The Project X Linac has been designed to have a very large “commonality” with the ILC project.**
- (At least) Two designs with large number of features overlapping the ILC
**Major R&D issues are being addressed in a separate HINS R&D program or are common with standard ILC issues (cavities gradient, MBK klys, etc).**
**Future work will include (in addition to HINS R&D):**
- Demonstration of  8/9 mode operations for ILC cavities
- Transient beam dynamics analysis with realistic RF distribution and feedback
- Definition and analysis of potential upgrades not excluded by the design
**The scale of the US regional industrialization effort for the ILC is at the same level of the number of cryomodules needed for the Project X Linac**