Beam Loss in the Extraction Line for 2 mrad Crossing Angle A'Drozhdin, N'Mokhov, X'Yang

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Beam Loss in the Extraction Line for 2 mrad
Crossing AngleA.Drozhdin, N.Mokhov, X.Yang
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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Beta and dispersion calculated by STRUCT in the
  extraction line with real extraction trajectory
  and QF1 multipoles from KoL to K9L

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Disrupted beam (file beam1 from cs21_hs) without
  vertical offset at IP (red), 3 sigma beam (blue)
  and beamstrahlung photon (file photon.dat from
  cs21_hs) beam (green) are printed out at QD0
  exit, SD0 exit, QF1 exit, QEX1 entry, QEX1 exit,
• QEX1B exit, SEX1 exit, and BHEX1 exit in the
  order of top to bottom and left to right.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Disrupted beam (file beam1 from cs21_hs) without
  vertical offset at IP (red), 3 sigma beam (blue)
  and beamstrahlung photon (file photon.dat from
  cs21_hs) beam (green) are printed out at QEX3
  exit, QEX4 exit, QEX 5 exit, BHEX2 exit, BYENE
  exit,BHEX3 exit, DUMP entry, and DUMP exit in the
  order of top to bottom and left to righ.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Disrupted beam (file beam1 from cs21_dy100_hs)
  with vertical offset at IP
• of 100 nm (red), 3 sigma beam (blue) and
  beamstrahlung photon (file photon.dat from
• cs21_dy100_hs) beam (green) are printed out at
  QD0 exit, SD0 exit, QF1 exit, QEX1 entry, QEX1
  exit, QEX1B exit, SEX1 exit, and BHEX1 exit in
  the order of top to bottom and left to right.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Disrupted beam (file beam1 from cs21_dy100_hs)
  with vertical offset at IP of 100 nm (red), 3
  sigma beam (blue) and beamstrahlung photon (file
  photon.dat from
• cs21_dy100_hs beam (green) are printed out at
  QEX3 exit, QEX4 exit, QEX 5 exit, BHEX2 exit,
  BYENE exit,BHEX3 exit, DUMP entry, and DUMP exit
  in the order of top to bottom and left to righ.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Disrupted beam (file beam1 from cs21_dy100_hs)
  with vertical offset at IP of 100 nm (green) and
  synchrotron radiated photons (red) from the
  disrupted beam are printed out at QD0 exit, SD0
  exit, QF1 exit, QEX1 entry, QEX1 exit, QEX1B
  exit, SEX1 exit, and BHEX1 exit in the order of
  top to bottom and left to right.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Particle loss distributions for beam with
  vertical offset at IP of 100 nm (file tail1 from
  cs21_dy100_hs) for increased aperture of beam
  line. As shown in the first two lines, aperture
  increase up to R260-300mm does not help to
  reduce electron loss in the region downstream of
  the last chicane below 1.5 KW/m. The only way to
  reduce heat load to the magnets is to place
  shadow collimators and synchrotron radiation
  masks between all magnets. Heat load to these
  collimators (bottom, left) is very high - 5-20
  KW/m.
• There is no primary particle loss at the magnets
  (bottom, right). Heat load from the
• secondary flux will be calculated using MARS.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Synchrotron radiation loss distribution along the
  extraction line for beam with vertical offset at
  IP of 100 nm (file beam1 from cs21_dy100_hs). The
  total synchrotron radiation power from the beam
  is 0.76 MW. This is 3.4 of the beam power.
  Synchrotron radiation load to the beam line
  elements can not be reduced by increasing of
  aperture (see top line). Photons are intercepted
  by the aperture at any case because they do not
  follow the trajectory of the beam line as the
  beam does. The only way to reduce heat load from
  synchrotron radiation to the magnets is to place
  synchrotron radiation masks with less aperture
  between magnets. Photon losses in the chicane
  region to the masks are approximately equal to
  5-10 kW (bottom line). There is no primary photon
  loss at the magnets at this case.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Particle (left) and photon (right) loss
  distributions for line with shadow collimators
  and synchrotron radiation masks between all
  magnets. Heat load to these collimators is very
  high - 10-30 KW/m. There is no primary particle
  and photon loss at the magnets (see second and
  bottom lines).

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• An example of typical synchrotron radiation loss
  distributions across the synchrotron radiation
  mask.

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Vertical-longitudinal view of energy deposition
  per train in first millimeters of the left jaw
  (left) and transverse view of energy deposition
  per train at shower maximum
• (z4 cm) (right).

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February 28, 2006 A.Drozhdin, N.Mokhov,
X.Yang

• Transverse view of residual dose at the upstream
  end of collimator HCOLL3 irradiated for 30 days
  20 average intensity and cooled for 1 day to
  convert to a full intensity one needs to multiply
  this plot by 5. Conclusions - total power
  dissipation in collimator HCOLL3 is 16kW - peak
  temperature rise is dT20C per train - estimated
  steady state temperature can be about 200C or
  higher, strongly dependent on cooling system (it
  is desirable to have a few times lower) -
  activation on the upstream end and on the
  beam-side (jaws) reaches 25 Sv/hr or 2500 R/hr
  (about 4 orders of magnitude above the limits) -
  peak accumulated dose reaches 10e12 Gy/yr which
  can severely limit the lifetime even for metals.