psb (ptc-orbit) 160mev space charge simulations with improved optics model: the vertical dynamic...
TRANSCRIPT
PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.
Space Charge meeting – CERN – 09/10/2014
Vincenzo Forte
Thanks to:E. Benedetto, M. McAteer, F. Schmidt
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013
Intensities and tunes
From ABP/LIS meeting
04/11/2013
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013
Initial beam characteristics and simulations set upTransverse planes
ex rms (normalized)
2.6757 (+/− 0.0844)
ey rms (normalized)
5.0542 (+/− 0.4521)
Longitudinal plane
Peak Voltage (h=1 & h=2)
8 kV & 8 kV
Relative phase 0 deg (short bunch)
Dp/p 2e-3
B. factor 0.25
ez rms (eVs) 0.17
Full length (ns) ~400
Intensity (@C500)
1.7e12 p.
Energy (MeV) 160
Simulations set up
S.c. method
2.5D direct space charge (128x128 & 64x64 mesh grids)
Nr. of initial m.p.
500e3
From ABP/LIS meeting
04/11/2013
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Improving the optics: closed orbit matching and correction
The measured CODs
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Improving the optics: closed orbit matching and correction
Without COD correction With COD correction
Thanks M. McAteer
Vertical COD
13 vertical DVTs -> DVT=COD matching component + COD correction component (from real machine values)
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Without COD correction
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Without COD correction – intensity evolution
From ABP/LIS meeting
04/11/2013
Without COD correction: the vertical transverse profiles…
Sim
ulati
ons
with
dire
ct s
pace
cha
rge
Sim
ulati
ons
with
out s
pace
cha
rge
only shift
no beam deformation
shift
beam deformation
The beam loses Gaussianity already after 5 ms!
PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 06/10/2014
With COD correction
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 06/10/2014
With COD correction – intensity evolution
Boundaries shape -> rectangle x=[-61, 61] mm y=[-29.5, 29.5] mm
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
With COD correction: The vertical transverse profiles…
Sim
ulati
on
with
out s
pace
ch
arge
Sim
ulati
on w
ith
spac
e ch
arge
(b
ound
arie
s)
Sim
ulati
on w
ith d
irect
sp
ace
char
geM
easu
rem
ents
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 06/10/2014
With COD correction - RMS emittances
Vertical
Horizontal
Direct space charge simulation (the one with boundaries is on-going)
Simulation with boundaries
With COD correction
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The losses distribution along the machine (simulated BLMs)
Period 2 & 6
Without COD correction
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The effect of the space charge model with boundaries. The coherent tune shift
Vertical plane (considering the max FFT amplitude)
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The effect of the space charge model with boundaries. The incoherent tune shift
with boundariesdirect space charge
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
With COD correction and random quad field errors – intensity evolution
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The effect of the chromaticity on the losses
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The effect of the chromaticity on the losses
A new MD will be performed in the next days to confirm the results.
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
The effect of the chromaticity on the losses
Footprint with DQy=-6.66 (turn 0) Footprint with DQy=-0.47 (turn 0)
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 06/10/2014
Summary and conclusions
• A dynamic tune scan toward the vertical integer resonance (Qy=4) in the PSB has been presented.
• At first, an improvement in the optics model has been performed, through the use of the DVT steerers, to create an equivalent model in terms of COD.
• Case1: With the new model, without COD correction, the simulations show great results in case the direct space charge module is added.
• Case 2: with a COD correction (the same as in the machine) is applied, the simulations underestimate the losses in case the direct space charge module is considered, while they overestimate the losses using the space charge module with boundaries.
• The qualitative behaviour of the transverse vertical profiles is reproduced in terms of beam deformation (toward a parabolic-like during the cycle).
• The presence of the boundaries has effects both in the coherent tune and in the incoherent tune shifts.
• 10 Simulations with randomly distributed errors (10 different seeds) show the same results in a sigma span similar to the real errors, as measured by M. McAteer (s=7e-4 for dk1)
• Simulations with chromaticity correction performed through the harmonic sextupoles family (XNOH0) show that, as expected, this may have a role in the losses induced by incoherent tune spread (to be confirmed through new MDs).
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 06/10/2014
Appendix
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Improving the optics: closed orbit matching and correction
PSB space charge studies update Vincenzo Forte – BE-ABP/LIS meeting – CERN - 04/11/2013 PSB (PTC-Orbit) 160MeV space charge simulations with improved optics model: the vertical dynamic integer case.Vincenzo Forte – Space Charge meeting – CERN – 09/10/2014
Improving the optics: closed orbit matching and correction