Prospects for Higher p Intensities at CERN R. CAPPI / CERN / 18.10.01

1
Prospects for Higher p Intensities at CERNR.
CAPPI / CERN / 18.10.01

• Introduction
• Main limitations (some of)
• acceptances vs emittances
• space-charge
• 5 t Continuos Transfer
• Example double batch injection
• List of various schemes
• Conclusion

2
Introduction

• a simplified summary of the paper CERN/PS
  2001-041 (AE)
• which is also a summary of few brainstorming
  meetings between PS and SPS specialists
• trying to answer the question is it possible to
  increase the intensity of the CNGS beam by a
  factor 2 or 3 ?
• the talk will be mainly devoted to Linac-PSB-PS
  and CNGS beam oriented
• speculations gt studies gt design
• All figures are PRELIMINARY and OPTIMISTIC
• I will not talk about collective effects ( xpt.
  sp. ch.), longit. beam dynamics issues ,
  transition crossing, etc.

3
Acceptance vs emittance
PS acceptance Ax60mm, Ay20mm ex2 lt 22mm,
ey2 lt 9mm
Ex2
Ax limit
Ey2
Ay limit
4
Space charge
Self field tune shift
To be safe , in the PS
NB
5
5 turn Continuos Transfer

• It is the way the PS uses to fill the SPS

CSPS 11 x CPS
PS
PS
SPS
X
Present system it works - it is lossy (20)
2
Q6.25
1
3
5
X
4
ES blade
6
Proposal for a new 5t CT

• The beam is adiabatically captured into 4 islands
  of a 4th order resonance excited with sextupoles
  and octupoles.
• Then it is extracted similarly to the present
  scheme.
• should be less lossy (5?)
• - has to be tested experimentally

7
present scenario with associated problems
50 MeV
L2
Limit
Nt 3.3
exlt 22 eylt 9
1.4 GeV, hlt0.9
DQ x,y 0.13 0.23
ex 25 ey 12
Nt 3
14 GeV/c 5t CT h0.8
NB in these transparencies 1) ex4sx2/bx
in mm 2) intensities Nt are in 1013 p 3) h is
the transfer efficiency 4) yp is the p flux on
target in 1013p/s
Limit
X
ex 4.2/3 1.4 ey 2.5
exlt 3 eylt 2
Nt 4.8
filling time 1.2s yp 4.8/6 0.8 G
1
8
Example double batch injection into PS
L2
50 MeV
Limit
Nt 2 x 2.4
exlt 22 eylt 9
1.4 GeV h1
ex 21 ey 9.2
DQ x,y 0.21 0.35
Nt 4.8 gt Intensity limit for a PS _at_ 1.4 GeV
14 GeV/c old 5t CT h0.8
Limit
exlt 3 eylt 2
ex 3.4/3 1.13 ey 1.4
...2 days ago, in a PS MD, E. and G. Metral et
al. have reached 4e13 ppp with moderate losses...
Nt 7.7
filling time 2.4s yp 7.7/7.2 1.07
G 1.34 yp 7.7/6.6 1.17 if PSB_at_.6s, G 1.46
9
Table (rev.) of various schemes
10
Conclusion

• a gain of 1.5 seems feasible though difficult
  (cost 0-3MCHF)
• a gain of 2 is maybe possible but will be more
  expensive (50MCHF) and very difficult
• a gain of 3 will be VERY expensive ( 400MCHF)
  and almost technically unrealistic
• first studies (concerning 1.1, 1.1a and 1.2) are
  encouraging, but we need clear priorities to
  continue at efficient speed