Status and realization of an high efficiency transport beam-line for - PowerPoint PPT Presentation

Status and realization of an high efficiency transport beam-line for laser-driven ion beams F. Schillaci IoP-ASCR, ELI-Beamlines Prague, Czech Republic And MEDical application @ ELI-Beamlines INFN-LNS Catania, Italy 25 th International Conference on Magnet Technology, francesco.schillaci@eli-beams.eu Amsterdam 27 August – 01 September 2017

Laser-driven ion beams ● Large proton number: 10 10 ÷ 10 13 ● Short bunch duration: few psec ● High Beam Current: kA ● !Low Emittance! : 5x10 -3 π mm mrad (microscale spot size but...) ● Wide Angular Aperture: 10 – 20° (if we are lucky ! ) ● High Energy Spread: ΔE/E >> 10% ● Low shot-to-shot reproducibilty 2

Laser-driven ion beams ● Large proton number: 10 10 ÷ 10 13 ● Short bunch duration: few psec ● High Beam Current: kA ● !Low Emittance! : 5x10 -3 π mm mrad (microscale spot size but...) ● Wide Angular Aperture: 10 – 20° (if we are lucky ! ) ● High Energy Spread: ΔE/E >> 10% ● Low shot-to-shot reproducibilty 3

Laser-driven ion beams ● Large proton number: 10 10 ÷ 10 13 ● Short bunch duration: few psec ● High Beam Current: kA ● !Low Emittance! : 5x10 -3 π mm mrad ● Wide Angular Aperture: 10 – 20° PIC simulations by J. Psikal ● High Energy Spread: ΔE/E >> 10% Expected @ ELI Beamlines ● Low shot-to-sho reproducibilty ● High dose-rate per bunch: ~10 9 Gy/sec 4

Laser-driven hadrontherapy 5

Laser-driven hadrontherapy 6

ELIMAIA & ELIMED 7

ELIMAIA & ELIMED Beam line elements: 1) Collection system 2) Selection system 3) Standard transport elements (quadrupoles and steerers) 4) in air dosimetry and irradiation Beam line features: 1) Tunability (deliver ion beams from 5 up to 60 MeV/u) with a controllable energy spread (5% up to 20%) an d 10 6 - 10 11 ions/pulse 2) Large acceptance 3) Flexibility to meet different User requirements 8

OUTLINE ● Design of the ELIMAIA Collection System ● Design of the ELIMAIA Selection System ● Additional transport elements ● Beam transport simulations 9

OUTLINE ● Design of the ELIMAIA Collection System ● Design of the ELIMAIA Selection System ● Additional transport elements ● Beam transport simulations 10

Energy selector Reference orbit and layout ESS Features Reference orbit Magnetic chicane based on a bunch compressor scheme Path length: 3,168m Two collimators φ = 30 mm, selection slit s x 40 mm. 11

Collection and Selection systems matching conditions Linearised chicane to define the PMQs set up according the (general) matching conditions: 1) Waist close to the slit on the radial direction M 12 =0 2) Parallel beam on the transverse plane M 44 =0 3) Transmission efficiency of 10% is ensured Input Beam: ● 60 MeV ● ±10° uniform angular spread ● ~40 μm diameter Constraints: ● Target-Quad1 minimum distance: 50 mm ● Minimum distance between Quads: 40 mm ● Target-ESS distance 2.05 m 12

Collection systems 80 mm 97 T/m 80 mm 120 mm 101 T/m 120 mm 160 mm 5 PMQs are requested to inject the different ion beam (H + and C +6 ) with different energy in the selection system 13

Permanent Magnet Quads Preliminary Design NdFeB N48H NdFeB N38UH (Br = 1,39 T (Br = 1,26 T Hc= 1273 kA/m) Hc= 1990 kA/m) Hybrid multiarray: ● 36 mm magnetic bore (3 mm shield + 30 mm for the beam) ● Inner Halbach trapezoidal (122 mm outer diameter, two NdFeB alloys) ● 2 external arrays with rectangular blocks F. Schillaci et al., JINST 10 T12001 (2015) (223 mm and 322 mm outer diameter) 14

Permanent Magnet Quads Preliminary Design M NdFeB N48H NdFeB N38UH H (Br = 1,39 T (Br = 1,26 T Hc= 1273 kA/m) Hc= 1990 kA/m) Hybrid multiarray: ● 36 mm magnetic bore (3 mm shield + 30 mm for the beam) ● Inner Halbach trapezoidal (122 mm outer diameter, two NdFeB alloys) ● 2 external arrays with rectangular blocks F. Schillaci et al., JINST 10 T12001 (2015) (223 mm and 322 mm outer diameter) 15

Permanent Magnet Quads Preliminary Design NdFeB N48H NdFeB N38UH (Br = 1,39 T (Br = 1,26 T Hc= 1273 kA/m) Hc= 1990 kA/m) Hybrid multiarray: ● 36 mm magnetic bore (3 mm shield + 30 mm for the beam) ● Inner Halbach trapezoidal (122 mm outer diameter, two NdFeB alloys) ● 2 external arrays with rectangular blocks F. Schillaci et al., JINST 10 T12001 (2015) (223 mm and 322 mm outer diameter) 16

Permanent Magnet Quads Preliminary Design NdFeB N48H NdFeB N38UH (Br = 1,39 T (Br = 1,26 T Hc= 1273 kA/m) Hc= 1990 kA/m) Hybrid multiarray: ● 36 mm magnetic bore (3 mm shield + 30 mm for the beam) ● Inner Halbach trapezoidal (122 mm outer diameter, two NdFeB alloys) ● 2 external arrays with rectangular blocks F. Schillaci et al., JINST 10 T12001 (2015) (223 mm and 322 mm outer diameter) Gradient uniformity Integrated Gradient <2% @ R = 12 mm uniformity < 0.3% @ R = 12 mm 17

Permanent Magnet Quads Final Design Model 36 mm magnetic bore (3 mm shield + 30 mm for the beam – same as INFN design) Inner Halbach trapezoidal (149 mm outer diameter, NdFeB N38UH – 27 mm bigger than INFN design) External array with rectangular blocks (266 mm NdFeB N48H – 56 mm smaller than INFN design) 18

Permanent Magnet Quads Final Design Model Requests Requests 19

PMQs + Mechanics ● 6 axis system ● Vacuum motors with low backlash gear (ration 100:1) ● Absolute potentiometers for position encoding ● High precision radiation resistant switches ● High torques vacuum carriages and rails 20

OUTLINE ● Design of the ELIMAIA Collection System ● Design of the ELIMAIA Selection System ● Additional transport elements ● Beam transport simulations 21

Emittance Growth and ESS acceptance PMQs ESS Emittance growth limited to the PMQs system and due to filamentations in the PMQs The highest variations in the emittance are within the first section of the beam-line, namely within the PMQs. The ESS is design to accept the beam transmitted by the collection system. 22

Emittance Growth and ESS acceptance PMQs ESS XX` YY` XY α 0.8401 0.3556 0.0002 β (mm/π mrad) 2.7094 2.4484 0.9112 Emit. Norm (mm/π mrad) 2.9506 3.9324 24.15 mm 2 Xmax Ymax X`max Y`max 14.97 mm 14.99 mm 8.632 mrad 7.162 mrad 23

Energy Selector Features n° of Dipoles B field Geometric Effective length Gap length 4 0.085 – 1.2 T 400 mm 451 - 448 mm 59 mm Good Field Field Curvature Bending angle Drift between region (GFR) uniformity radius dipoles 100 mm < 0.5 % 2.570 m 10.10° 500 mm ● Magnet efficiency: 98% ● Packing factor: 98% ● 115.5x168 mm coil section (11x16 turns, 0,5 mm of insulator, 6 mm water channel) ● Max current ~200 A ● Total weight ~3 Tons ● 40 kWatt in total F. Schillaci et al., JINST 11 P08022 (2016) 24

Energy Selector Features n° of Dipoles n° of Dipoles B field B field Geometric Geometric Effective length Effective length Gap Gap length length 4 4 0.06 – 1.226 T 0.06 – 1.226 T 400 mm 400 mm 450.23 – 448.34 mm 450.23 – 448.34 mm 55 mm (shim) 55 mm (shim) Good Field Good Field Field Field Curvature Curvature Bending angle Bending angle Drift between Drift between region (GFR) region (GFR) uniformity uniformity radius radius dipoles dipoles 100 mm < 0.5 % 2.570 m 10.10° 500 mm 100 mm 0.4 % 2.570 m 10.10° 500 mm ● Magnet efficiency: 97% ● Packing factor: 99% (1 mm lamination) ● 116x116 mm coil section (10x10 turns, 0.4 mm of insulator, 4 mm water channel) ● Max current: 300 A ● Total weight: 2.6 Tons ● < 28 kWatt in total Reinforcemente to guarantee 42 mm inner clearence in the vacuum chamber 25

Double Dispersive Mode Magnetic Chicane 30 mm collimator upstream and downstream the chicane (200 mm far from dipoles) Variable slit aperture size (4 up to 20 mm) F. Schillaci et al., JINST 11 P08022 (2016) 26

Not just a magnetic chicane... Towards an active energy modulator If the current is changed each Current ramp from second (each laser shot) the system 0 up to max current could be used as an active energy in 0.28s (B = 1,2 T) modulator system Induced sextupole due to the eddy current on the vacuum chamber Induced current density J max = 1,15 x 10 6 A/m 2 can be neglected after 0.31s F. Schillaci et al., JINST 11 P08022 (2016) Eddy Current Loop 27

Not just a magnetic chicane... Towards an active energy modulator Harmonic components vs time Eddy Current Loop A general model for harmonic component study is presented in my talk Error and optics study of a permanent magnet quadrupole system [Thu-Mo- Or33] 28

Not just a magnetic chicane... Towards an active energy modulator More realistic calculation: 20 % field variation (1 T → 1,2 T) in 1 sec J max = 0.5 x 10 5 A/m 2 29

OUTLINE ● Design of the ELIMAIA Collection System ● Design of the ELIMAIA Selection System ● Additional transport elements ● Beam transport simulations 30

Quads and Steerers Quads Specs: Correctors Specs: Iron length: 296mm xy steering magnets Packing factor 98% B max: 300 gauss Effective length: 331.5 mm Geometrical length: 150mm Gradient (max): 10T/m Bore: 70 mm GFR: 55 mm 31

Quads and Steerers 32

OUTLINE ● Design of the ELIMAIA Collection System ● Design of the ELIMAIA Selection System ● Additional transport elements ● Beam transport simulations 33