Download presentation

Presentation is loading. Please wait.

Published byKaleigh Cawood Modified over 2 years ago

1
A 10 GeV, 4 MW, FFAG, Proton Driver at 50 Hz G H Rees, RAL

2
Non-scaling, Non-linear FFAGs Categories for FFAG Lattice Cells of Five Magnets: 1. IFFAG: isochronous, no Q v =n and 2Q v =n crossing 2. IFFAGI: IFFAG with combined function insertions 3. NFFAG: non-isochronous, high/imag -t, no Q var’n 4. NFFAGI: NFFAG with insertions, some Q h variation 1 and 2: rapid acceleration of muons or electrons 3 and 4 : high power proton drivers or medical rings

3
4 MW Proton Driver Arrangement Muon yields optimal for 6 - 10 GeV (S Brooks, RAL) Choose: 10 GeV, 50 Hz to reduce target shock 3 GeV booster for 3 – 10 GeV NFFAGI 2, 25 Hz or 1, 25 Hz booster (R =2.2 R b ) 0.18 GeV H ‾ linac for low bunch areas 5 bunches at h = 5 for RCS booster(s) Transfer: 5 (10 13 protons/bunch) to the NFFAGI Bunch to: 1 ns (rms) adiabatically (h = 33 & 198)

4
Longitudinal bunch area The longitudinal bunch area (in eV sec) is: A = (8Rα/(ch)) ((2 V(I- sc )E o ) / (h )) ½ For a small longitudinal bunch area, choose a low value of injection energy and ring radius Choose E o ( - 1) = 0.18 GeV and R b 50.0 m Choose the bunch & harmonic number (h) = 5 Compressed bunch area needed 0.66 eV sec

5
4 MW, Proton Driver Layout 0.18 GeV H ‾ Achromat 0.18 GeV H ‾ Linac 10 GeV, 50 Hz, N = 5, NFFAGI with 10 13 protons per bunch 3 GeV, 50 Hz, h =5, RCS (1 at 50 Hz, or 2 at 25 Hz)

6
NFFAGI Design Criteria For compression of the 5 bunches at 10 GeV: Design for a gamma-t value at 10 GeV 20 Design for longitudinal bunch areas 0.66 eV s Adiabatic acceleration & comp. with h = 33, 198 Design the NFFAG ring with lattice insertions, to ease injection, ejection & beam loss collection Use two insertions to allow most flexibility, eg: 21 normal and 13 insertion cells per insertion

7
Acceleration and Compression Systems Driver-booster circumference ratio: 2.2 to 1 Booster rf range (h=5): 2.6164 to 4.670 MHz Driver rf range (h=33): 14.011 to 14.370 MHz Compression frequency (h=198): 86.222 MHz Peak accelerating voltage per turn: 1.0 MV Peak compression voltage per turn: 2.56 MV

8
Lattice Cell Options Normal cell Insertion cell Magnet types Doublet D D1 + T0 + D2 2 + 7 Triplet T T1 + T2 + T1 2 + 4 Pumplet P1 P2 3 + 3 Easiest solution is to match P1 and P2 pumplet cells: P1 has a smaller β-range than either D or T The insertion has only one type of cell, P2 P2 has the smallest closed orbit “lever arm” No 2 dispersion suppressors, as too many are needed

9
10 GeV, Normal & Insertion Cell Layouts bd(-) BF(±) BD (+) BF(±) bd(-) O 0.5 0.5 0.5 0.5 O 0.60 1.25 1.9 1.25 0.60 0.651 Normal cell (5.294º, 8.902 m) 0.651 2.2 Insertion cell (5.294º, 12.00 m) 2.2 There are two superperiods of 21 normal & 13 insertion cells At 10 GeV: Q v = 13.72, Q h = 19.36, -t = 20.4, R = 109.17 m

10
NFFAGI Lattice Design Use equal bend, normal and insertion, pumplet cells Arrange ~ matching for a normal and insertion cell Arrange integer, insertion tunes eg Q h = 4 & Q v = 3 The normal cells in an insertion are then matched Seek unchanged closed orbits on adding insertions by varying the normal cell field gradients and tunes Then, dispersion match is almost exact for insertions Small ripple remains in β h and β v (max) in insertions

11
Non-Linearity Compensation Crossing of the 3rd order resonance: 3Q h = 58 Insertion and arc 3(Q h ) values: 3Q h = 3(4, 5⅔ ) Hence, no 3rd order excitation for: 3Q h = 58 Crossing of 4th order resonance: 2Q h + 2Q v = 66 Insertion and arc values for: 2(Q h + Q v ) = 2(7, 9½ ) So, no 4th order excitation for: 2Q h + 2Q v = 66 Crossing of the 4th order resonance: 4Q h = 77 Insertion and arc 4(Q h ) values: 4Q h = 4(4, 5⅝ ) Some small 4th order excitation for: 4Q h = 77

12
NFFAGI Lattice Results Satisfactory matching at the 24 reference energies: 10.0…..6.8, 6.5…..5.0, 4.75…..4.0, 3.8…..3.0 GeV. Q v =13.72 throughout the 3 to 10 GeV energy range. Dispersion match is found by varying K(bd) and h : T =10.0……6.8, 6.5…. 5.0, 4.75..4.0, 3.8…3.0 GeV Q h =19.36, 19.31, 19.3, 19.29, 19.2, 19.2, 19.2, 19.2 Gamma-t becomes imaginary for the low energies

13
Combined Function Magnet Fields (T) Magnets Insertion Normal cell bd -1.70 to -1.18 -1.70 to -0.98 BF 1.75 to -0.15 1.75 to -0.27 BD 0.54 to 1.55 0.54 to 1.59 T max bending ratios; bd : BF : BD ~ - 0.47 : 1.0 : 0.23 (Ratios in muon ring; bd : BF : BD ~ - 1.0 : 1.0 : 1.0)

14
Beam Loss Collimators Vertical: Locate in 4, adjacent, long, insertion straights Use 1, primary and 3, secondary, 5 kW collimators Use tapered units for lower, high energy acceptance Horizontal: Locate in the first three, vertical, collimator straights Use 1, primary and 3, secondary, 5 kW collimators Use angled units for collimation at 3 and 10 GeV

15
10 GeV NFFAGI versus RCS Pros: Allows acceleration over more of the cycle, No need for ac magnet p/s or ceramic chamber, Gives more flexibility for the holding of bunches, Required is one NFFAGI ring, but two RCS(s), Allows operation at 50 Hz instead of at 25 Hz, with 5 10 13 ppp at target, instead of 10 14 ppp. Thus, there is half the target shock per pulse. Cons: needs a larger (~ 0.33 m) radial aperture

Similar presentations

OK

Proton / Muon Bunch Numbers, Repetition Rate, RF and Kicker Systems and Inductive Wall Fields for the Rings of a Neutrino Factory G H Rees, RAL.

Proton / Muon Bunch Numbers, Repetition Rate, RF and Kicker Systems and Inductive Wall Fields for the Rings of a Neutrino Factory G H Rees, RAL.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on regular expression in php Ppt on blood stain pattern analysis history Ppt on electricity distribution system in india Ppt on network switching modes Ppt on biography of bill gates Ppt on rulers of uae Ppt on share trading in india Ppt on garden of five senses A ppt on srinivasa ramanujan Ppt on challenges of democracy in india