FFAG Studies at BNL Alessandro G. Ruggiero Brookhaven National Laboratory FFAG’06 - KURRI, Osaka, Japan - November 6-10, 2006

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'062 of 17 FFAG Studies at Brookhaven South Corner: Muons Palmer, Berg, … North Corner: Protons Ruggiero, Trbojevic Dejan->Medical, Gantry, eRHIC,… Sandro->AGS-FFAG, Neutrino Factory, MA-LE-PD, (RIA, electrons,…)

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'063 of 17 AGS-FFAG New AGS Injector for Upgrade to 1-4 MW at 28 GeV Rep Rate Hz Protons10 14 ppp Circumference809 m FFAGFDF Triplet Non-Scaling Lattice Linear Field Profile LinacFFAG AGS After-Burner 400 MeV 1.5 GeV 20 GeV 40 GeV All in the same AGS Tunnel FFAG Reference Design

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'064 of 17 NuFact - Requirements Kinetic Energy GeV11.6 GeV Average Power4 MW 4 MW Repetition Rate50 Hz50 Hz Number of Bunches Bunch Length (rms)1 - 3 ns2 ns Number of Protons4.31 x per pulse Protons per Bunch0.862 x 10 13

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'065 of 17 Accelerator Architectures Rapid-Cycling Synchrotrons Super-Conducting Linacs FFAG (cyclotrons, RLA, microtrons, …) SCL CEBAF Dog-Bone FFAG The case for a Non-Scaling FFAG A.G. Ruggiero, BNL Report C-A/AP/219, Oct also in proceedings of NuFact’06, Frascati, June 2005

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'066 of 17 FFAG Accelerators for Proton Driver Single-turn Extraction Single-turn Transfer 400-MeV Injector 3 FFAG Rings GeV GeV GeV Multi-turn Injection FFAG’s are Non-Scaling of about the same circumference and similar structure, located in the same enclosure. Bunch Compression is done in the last ring at the end of acceleration. The scheme allows flexibility of choice of energy, intensity, rep rate. It can suit any requirements for muon production and collection

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'067 of 17 Three - FFAG Accelerator Rings (1) Injector Ring * Low-Energy Ring High-Energy Ring Kinetic Energy: Inj. Ext. GeV  Inj. Ext  p/p ±% Circumferencem No. of Periods136 Period Lengthm Harmonic Number RF  = m MHz MHz/ms * A.G. Ruggiero, “1.5-GeV FFAG Proton Accelerator for the AGS Upgrade”, Invited Talk to EPAC-04, July 6-11, 2004, Lucerne, Switzerland. T a = 10 ms

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'068 of 17 Lattice Parameters D FF SS gg Non-Scaling Lattice Injector Ring Low-Energy Ring High-Energy Ring Drifts: S g mmmm 2 x x x F-sector: Length Field min Field max Gradient m kG kG/m D-sector: Length Field min Field max Gradient m kG kG/m  x max, in F in D cm

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'069 of 17 Linear Field Distribution (kG vs. cm) Injector Ring High-Energy Ring Low-Energy Ring

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0610 of 17 Lattice Functions Phase Adv. / Cell H V o o Betatron Tune, H V Nat. Chromaticity, H V Transition Energy,  T i All Rings Linear Field Profile Injection Extraction

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0611 of 17 Tune Variation & Radial Compactness same result for all Rings  = (p - p inj) / p inj F D F Half a Period

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0612 of 17 Three - FFAG Accelerator Rings (2) Injector Ring Low-Energy Ring High-Energy Ring Energy Gain / TurnMeV No. of Revolutions RF Peak VoltageMVolt Acceleration Periodms Injection Periodms Repetition RateHz Gap VoltagekVolt50 Gaps per Cavity222 No. of Cavities51020

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0613 of 17 Three - FFAG Accelerator Rings (3) Injector Ring Low-Energy Ring High-Energy Ring Protons / Cycle4.31 x Average CurrentmA0.345 Average PowerMW Nor. Emittance (full)  mm-mrad 400 Act. Inj. Emittance  mm-mrad Half Vert. Beam Sizecm Half Hor. Beam Sizecm Bunching Factor, B  /  √2π rms Bunch Length,  ns Tune-Shift Injection

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0614 of 17 RF Frequency & Power Injector Ring Low-Energy Ring High-Energy Ring MHz MW # turns MW 250 kW/cavity

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0615 of 17 Injector Ring and Injection Injection EnergyMeV400 H – Source CurrentmA35 RFQ Transmission%80 Chopping Ratio%5/75 x 75 Inject. Beam CurrentmA1.4 Inj. Protons / turn0.33 x Injected Turns1306 Pulse Lengthms4.924 Duty Cycle0.246 Chopping FrequencyMHz1.326 B1 B2 C1 Foil C2 From DTL Injection Orbit Bump Orbit RF Ion Source ?

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0616 of 17 Extraction and Targetting The Revolution Period at Extraction from the High-Energy Ring T 0 = 2.70 µs Beam Bunches are extracted individually every n turns Pulse Duration n = 1n T 0 = 2.70 µs µs Kicker Septum F D F F D F F D F

November 8, 2006A.G. Ruggiero (BNL) -- FFAG'0617 of 17 NuFact - Conclusions  FFAG Accelerators for Neutrino Factories are feasible  Issues: Space Charge at Injection Multiple Resonance Crossing Injector Linac (400-MeV DTL or ????) Multi-turn Injection of H – Magnet Feasibility Fast RF sweep (ferrite, RF power) Collimation Numerical Tracking Cost Estimate  It is possible to raise the Repetition Rate --> 1 kHz or CW Mode of Operation (Harmonic Number Jump)