ESSnu SB transfer line update N Blaskovic ESS

ESSnu. SB transfer line update N. Blaskovic ESS 2020 -04 -24 BPS meeting 1

Introduction • ESSnu. SB A 2 R transfer line design based on drawing by Rasmus Johansson: – Total transfer line length: 272 m – Tunnel arc length: 132 m – Tunnel arc bending radius: 110 m • Dipole strengths at 0. 15 T for Hˉ stripping loss limit of 3 x 10 -8/m (Wildner & Goddard) • With help from Mamad Eshraqi & Björn Gålnander N. Blaskovic BPS meeting 2

Tunnel design beam from linac 68. 75° 100 m beam to ring N. Blaskovic BPS meeting 3

Lattice cell structure • Lattice cell based on 8. 52 m long cell from HEBT with quadrupole doublet at start: N. Blaskovic BPS meeting 4

Accumulator ring depth options • Ring depth adjusted by choosing number of vertical bending cells in transfer line: N. Blaskovic BPS meeting 5

Matching HBLp to A 2 R • Combining 7. 0_HBLp line and 8. 0_A 2 R line into a single lattice file • Input beam parameters from distribution at end of 6. 0_MBL line • Match HBLp to A 2 R line using last 4 quads in HBLp line • No multiparticle tracking so far N. Blaskovic BPS meeting 6

View from above HBLp N. Blaskovic BPS meeting A 2 R 7

View from the side HBLp N. Blaskovic BPS meeting A 2 R Depth 7. 864 m 8

Structure phase advance Depth 7. 864 m Smooth transition to 45°/90° No phase advance warnings N. Blaskovic BPS meeting 9

Lorentz stripping loss Depth 7. 864 m Peak stripping loss: 9 x 10 -8/m N. Blaskovic BPS meeting 10

Beam envelopes Depth 7. 864 m N. Blaskovic BPS meeting 11

Beam envelopes (zoomed in) Depth 7. 864 m Final dispersion ≤ 1 mm What do blue and purple lines mean? N. Blaskovic BPS meeting 12

More plots BPS meeting 13

Emittance Depth 7. 864 m N. Blaskovic BPS meeting 14

Energy Depth 7. 864 m N. Blaskovic BPS meeting 15

Energy gain Depth 7. 864 m N. Blaskovic BPS meeting 16

Period length Depth 7. 864 m Rounding errors in dipole lengths give rise to small ‘steps’ N. Blaskovic BPS meeting 17

Other depths BPS meeting 18

View from above Depth 8. 887 m HBLp N. Blaskovic BPS meeting A 2 R 19

View from the side HBLp N. Blaskovic BPS meeting A 2 R Depth 8. 887 m 20

Structure phase advance Depth 8. 887 m Smooth transition to 45°/72° No phase advance warnings N. Blaskovic BPS meeting 21

Lorentz stripping loss Depth 8. 887 m N. Blaskovic BPS meeting 22

Beam envelopes Depth 8. 887 m N. Blaskovic BPS meeting 23

Beam envelopes (zoomed in) Depth 8. 887 m Final dispersion ≤ 1 mm N. Blaskovic BPS meeting 24

Emittance Depth 8. 887 m N. Blaskovic BPS meeting 25

View from above Depth 9. 514 m HBLp N. Blaskovic BPS meeting A 2 R 26

View from the side HBLp N. Blaskovic BPS meeting A 2 R Depth 9. 514 m 27

Structure phase advance Depth 9. 514 m Smooth transition to 45°/72° No phase advance warnings N. Blaskovic BPS meeting 28

Lorentz stripping loss Depth 9. 514 m N. Blaskovic BPS meeting 29

Beam envelopes Depth 9. 514 m N. Blaskovic BPS meeting 30

Beam envelopes (zoomed in) Depth 9. 514 m Final dispersion ≤ 1 mm N. Blaskovic BPS meeting 31

Emittance Depth 9. 514 m N. Blaskovic BPS meeting 32

Back-up BPS meeting 33

Stripping rates from Elena Wildner & Brennan Goddard N. Blaskovic BPS meeting 34

from Elena Wildner & Brennan Goddard N. Blaskovic BPS meeting 35