EXTRACTION AND RECOMBINATION LINES J.L. Abelleira, W. Bartmann. J. - - PowerPoint PPT Presentation

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EXTRACTION AND RECOMBINATION LINES J.L. Abelleira, W. Bartmann. J. - - PowerPoint PPT Presentation

Oct 23, 2022 253 likes •433 views

Prvessin, 6 November 2014 APERTURE STUDY ON THE PSB EXTRACTION AND RECOMBINATION LINES J.L. Abelleira, W. Bartmann. J. Bourburgh Thanks to: g Aperture study of present septa Comparison with future septa Study including

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SLIDE 1

APERTURE STUDY ON THE PSB EXTRACTION AND RECOMBINATION LINES

J.L. Abelleira, W. Bartmann. J. Bourburgh

Thanks to: g

Prévessin, 6 November 2014

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SLIDE 2
  • Aperture study of present septa
  • Comparison with future septa
  • Study including extraction
  • Study possibilities to increase aperture (more kicker strength…)
  • Could we install the lengthened septa in the present machine?

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 2

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SLIDE 3

The BT transfer line

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 3

From PS BOOSTER

3 septa

1064 1300 1225 995

1.4 GeV 2.0 GeV B x1.3  Bdlx1.3 SMV10 SMV20

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SLIDE 4

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 4

B B

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SLIDE 5

Beam size definition

Beam size definition

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 5

(Half) beam sizes computed as 𝐵𝑦,𝑧 = 𝑜𝑡𝑗𝑕 ∙ 𝑙𝛾 ∙ 𝛾𝑦,𝑧 ∙

𝜗𝑂;𝑦,𝑧 γ𝑠β𝑠 + |𝐸𝑦,𝑧σ| + 𝐷𝑃 ∙ 𝛾𝑦,𝑧 𝛾𝑁𝐵𝑌;𝑦,𝑧

CO = 1.5 mm Ek = 1.4 GeV 𝑙𝛾 = 1.2 𝜗𝑂,𝑦 [m] 𝜗𝑂,𝑧[𝑛] 𝜏 LHC 2 2 1.07x10-3 Fixed target 10 5 1.35 x10-3 ISOLDE 15 9 1.35 x10-3

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SLIDE 6

Orbit comparison

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 6

Element Present [mrad] Upgraded [mrad] dbt1bvt10 Bending magnet 76.80 75.27 dbt1smv10 Septum 73.56 72.03 dbt4bvt10 Bending magnet 76.80 75.27 dbt4smv10 Septum 73.56 72.03 dbtbvt20 Bending magnet 74.17 72.82 dbtsmv20 Septum 71.31 69.96

In order to to keep same orbit at SMV exit, trajectories are rematched

Present septum future septum

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SLIDE 7

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 7

Gap height (horizontal plane) [mm] Gap width (vertical plane) [mm] blade thickness [mm] Present 60.4 102 5 Upgraded 60.4/62.0 102 5

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SLIDE 8

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 8

Wider septa apertures do not allow more beam nsig=1.0 nsig=1.5 nsig=2.0 nsig=2.3 nsig=2.5 Limitation in septum blade, coming from distance between beam centers No Limitation here

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SLIDE 9
  • 1. BT1.SMV10

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 9

ISOLDE Fixed target LHC Vertical Present 2.6 3.5 5.6 Upgraded 2.5 3.4 5.4 Horizontal Present 2.5 3.1 7.1 Upgraded 62.0 mm 2.6 3.1 7.2 Upgraded 60.4 mm 2.5 3.1 7.0

Blade: 5 mm FUTURE PRESENT

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SLIDE 10

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 10

  • 1. BT4.SMV10

ISOLDE Fixed target LHC Vertical Present 2.6 3.5 5.6 Upgraded 2.5 3.4 5.5 Horizontal Present 2.5 3.1 7.1 Upgraded 62.0 mm 2.6 3.1 7.2 Upgraded 60.4 mm 2.5 3.1 7.0

FUTURE PRESENT

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SLIDE 11

BT.SMV20

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 11

ISOLDE Fixed target LHC Vertical Present 2.0 2.7 4.2 Upgraded 1.9 2.6 4.2 Horizontal Present 3.0 3.9 8.7 Upgraded 62.0 mm 3.1 3.9 8.8 Upgraded 60.4 mm 3.0 3.8 8.6

FUTURE PRESENT

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SLIDE 12

Extraction septum

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 12

  • No additional limitation found in PSB extraction septum BE.SMH (3.0 σx, 5.5σy for ISOLDE beam)
  • No additional limitation found in extraction kicker

Circulating beam Extracted beam

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SLIDE 13

LIU-ABT systems : PS. Beam parameters 13

Recombination orbits

As the limitation comes from the distance at the exit of the septa, more beam will fit if the distance is increased But this fights against the kickers, as more kicker strength is needed!

f = 1

𝑙𝑚

Recombination quadrupole of integrated strength kl

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SLIDE 14

Recombination orbits

LIU-ABT systems : PS. Beam parameters 14

Another solution would be to move the quadrupole, but not enough space between septa and quad For these reasons, the present recombination geometry is kept.

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SLIDE 15

Situation with present beams

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 15

Richard Catherall

  • For the moment (and for the last 10 years) there are no specific requests for a primary

proton beam energy at 1.0 GeV for any experiments at ISOLDE.

  • The 1 GeV beam is therefore not essential to the ISOLDE physics program and to the best
  • f my knowledge, there are no plans to request this primary beam energy in the future.
  • The possibility to switch between 1.4GeV and 2 GeV is of great importance as the

different energies are required for an optimal production of specific isotopes. Could we install the magnets during this RUN 2? worst-case energy case would be the same: 1.4 GeV I expect a very small difference in beam losses from the present situation.

  • I will give the exact number.
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SLIDE 16

Conclusions

  • With the present recombination geometry, the limiting factor in aperture is the distance between

the center of deflected and undeflected beams at the exit flange of the septum.

  • For the reason explained above, an increase on the gap width is not justified.
  • With the new septa there is a small reduction in the vertical aperture that comes from the increase

in length, but this value is very small (in the order of 1/10 sigma)

  • An increase of the gap height (horizontal aperture) gives a very small gain (1/10 sigma in the best

case) so in principle is better to keep the same dimension.

APERTURE SPECIFICATION OF PSB-PS RECOMBINATION SEPTA 16