New fast ion inflector for SPS Brennan Goddard
New fast ion inflector for SPS Brennan Goddard; Volker Mertens; Jan Borburgh; Laurent Ducimetiere; Etienne Carlier; Thomas Kramer; Jan Uythoven; Francesco Maria Velotti; Luc Sermeus
Overview • The attempts to find a solution with upgrades of the existing MKP kickers not promising – Reducing rise time of the MKPA/C kickers results in a huge system with 12 m magnetic length – Combining with fast pulsed septum means it is impossible to dump the non-kicked injected beam – Problems with Q 20 optics for LHC beams • After several iterations, the best solution seems to be a separate new MKP-I and fast pulsed septum for ions only – Existing kickers all stay, for p+ injection – Open C core kicker required for injection dump aperture
Assumptions on MKP-I parameters (short circuit) Magnet length Impedance Gap height Gap width mu 0 current Inductance Capacitance Filling time B field B. dl N magnets Brho kick per tank Kick m Ohm m m Hm-1 A H n. F ns T Tm Tm mrad 0. 35 50 0. 044 0. 105 1. 26 E-06 1000 1. 05 E-06 4. 2 42. 0 0. 0286 0. 0100 8 90. 0 0. 1111 0. 8888
Comments on rise time specification • 1 -99% in 50 ns will probably be very difficult to meet – Thyratron switch on time, long distance between switch and magnet, . . . – Some ways to try to gain, like saturating ferrites in entrance box, . . . • For now assume 10 -90% in 50 ns should be feasible – Evaluation needed of damper performance • Flat-top ripple specification is needed • Detained simulation and eventually prototyping will be needed to define exact performance
Open C-core magnet geometry 0, 1 0, 08 0, 06 0, 04 0, 02 -0, 08 -0, 06 -0, 04 -0, 02 44 mm 0 -0, 1 110 mm 0 -0, 02 -0, 04 -0, 06 -0, 08 -0, 1 0, 02 0, 04 0, 06 0, 08 0, 12 0, 14
Tank length 8 magnets 150 mm 350 mm 150 mm Total = 8*350 + 9*150 = 4150
Layout in SPS MSI-V MKP-I
Aperture envelopes H V
Optics – 26 Ge. V p+ (as 2012)
Optics – 14 Ge. V p+ (as 2012)
17 Ge. V/c Pb 84+ ions without injection bump
Dumping of injected ion beam (continue to use TBSJ for p+ as at present) MBB. 12070/90 chamber, with 10 mm offset QD. 12110 chamber 30 mm Dump block
Dumping of injected ion beam • Could conceivably have a dump block in a new location just upstream QD. 121 • Could misalign MBB. 12070/90 by -10 mm in H ~2 m available
17 Ge. V/c Pb 84+ ions with injection bump • Injection bump ensures ion beam is dumped with a kicker missing • Note that this is less effective for the Q 20 optics
MSI-V septum • • • Recovered PSB recombination septa 2 x 1060 m septum length, 2500 mm total Maximum deflection 18 mrad at 60 Tm (12 at 90 Tm) 5 mm thickness, 60. 4 mm vertical gap 3 ms pulse length with 3 rd harmonic New power supply needs to be developed and built
Septum magnet parameters Magnetic length 996 + 996 mm Physical length 1060 + 1060 mm Gap height 60. 4 mm Horizontal aperture 102 mm Magnetic field 0. 541 T ∫B. dl 0. 538 + 0. 538 T. m Deflection angle 6+6 mrad Ipeak 26. 0 k. A Pulse width ~3 ms Septum thickness 4. 5 + 0. 5 (copper + s. steel) mm Vacuum tank length ~ 2500 mm Expected lifetime 60 M pulses
Septum strategy • For LIU-PSB BT. SMV magnets will be removed from the vacuum tanks for new. • As from 2017, at least 3 magnets will be available, with 6 more after LS 2. • These magnets could be re-used to construct 1 MSI-V for installation in LS 2 and spares to be build after LS 2.
Possible issues • Space in BA 1 – Need new space for generators and controls but very little available – may need building extension (time, money) • Resources for development and construction – Many other concurrent projects until at least LS 2, no spare capacity in ABT group
Work needed • Error/failure study • Dump design • MKP-I kicker simulations (field homogeneity, geometry, magnetic field pulse, …) • Controls and interlocking • Septum powering design • Instrumentation requirements • Damper performance evaluation • Extra impedance evaluation • Cost estimates • Manpower estimates • Realistic schedule estimate
Conclusions • Requirements for 50 ns ion injection can be met, provided an open C-core kicker of specified performance can be built • The kicker system is rather compact at 8 x 0. 35 m magnets, in 4. 150 m total (maybe split in 2 tanks for practical reasons) • The septa exist and can be adapted – powering needed • The ion beam can also be dumped with the addition of a dump block just upstream QD. 12110 • Rise time of kicker still very critical – probably tough to meet 1 -99%. Need to investigate performance with 1090% (damper) • Increased machine impedance to evaluate
- Slides: 20