MTE vs CTD.Manglunki for BE/OP

- pictures from M.Giovannozzi- details in “Fifty years of the CERN Proton Synchrotron (Vol I)”CERN-2011-004

Why a Continuous Transfer (CT)?

• The SPS circumference is 11 times the one of the PS• First tests: extraction over 11 turns

– Need gap for SPS kicker– 10-turn version up until 7x1012 ppp

• Present version over 5 turns– Two PS extractions to fill 10/11 of the SPS circumference– Two gaps of 1/22 of the SPS circumference for the SPS kicker

2USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki

Principle of the current CT• Horizontal tune 1/4th integer (6.25)• Beam brought close to electrostatic septum by slow bump• Beam horizontally shaved on electrostatic septum in 5 steps by fast bump

• Resulting horizontal emittance smaller than vertical one– SPS vertical acceptance smaller than horizontal

=> plane exchange before SPS3USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki -4

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Issues of the current CT:Working Group on Losses

• Observations of the WGL:– 10 to 15% of the beam sent to the SPS for fixed target is lost on SEH31. Taking

into account the subsequent machine efficiencies (injection, capture, acceleration and slow extraction), it is a conservative estimation to state that for 1e20 protons on target, more than 2e19 14GeV/c protons are lost on SEH31!

– SEH31 is one of the most irradiated locations of the PS– Changing cable or oil gives a collective dose of 1msV

• Recommendation from the WGL – Study a new scheme, proposed by R.Cappi in 2000, see:

R. Cappi, M. Giovannozzi, "Novel Method for Multi-Turn Extraction: Trapping Charged Particles in Islands of Phase Space'', CERN PS 2001-015 (AE)

• See PS/OP/Note 2001-009

4USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki

Extraction line

Slow bump

Sextupole magnets

Extraction septum

Octupole magnets

Flying wires

Kicker magnet

Section 71

Section 64

Section 55

Section 16

Section 21

Section 20

Section 54

Principle of the new MTE• Use non linear fields to create stable islands

in the horizontal phase space (“transverse splitting”)• Use fast kicker to jump magnetic septum and extract the 5 beamlets

5USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki

Current situation• MTE commissioned

– Similar performance as CT– Still more losses in SPS, being improved– Horizontal emittance out of PS

larger than CT => no plane exchange in TT10

– Still some problems with interlocks, hopefully solved before the end of this week

– Otherwise ready to be put in operation

• Proposal to switch to MTE on Monday 21/9/2015– In the shadow of PS intervention

and users exchange in the North Area– Setting up time will be identical,

no time lost (or hardly any)

6USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki

Thanks for your attention!

7USERS’MEETING – September 17th, 2015 MTE vs CT - D.Manglunki