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CLIC Muon Background Simulation Using BDSIM

This is an ongoing project to simulate the muon flux into the CLIC detector due to beam halo collimation. All data presented here are provisional.

Overview

BDSIM gmad files were generated from the v_09_04_01 MAD decks, including all apertures. Cross checks were performed using core electron and positron distibutions. A tunnel geometry was created including a tunnel floor, beam line offset, concrete walls and surrounding soil. A tapered spoiler geometry was created. Relevant physics processes were turned on and cross section biased to reduce required computing time. The simulation was run on the RHUL grid farm with 1.5 T eV electrons and positrons as the primary particles (halo distribution files generated by H. Burkhardt at CERN using htgen).

Data Files

Processes and biasing

At 1.5 T eV, the dominant process is gamma-> mu- mu+ and electron positron annihilation can be ignored. Therefore electrons incident and positrons incident produce similar numbers of muons.

The following cross section biasing was used:

gamma -> muons: 1e4

annihilation -> muons: 1e4

File formats

Format 1

x' y' z' x[mum] y[mum] z[m] charge[e] energy[GeV]

Energy is the energy of the particle in G eV. x and y are the positions of the particle from the reference trajectory in mum. x' y' and z' are the normalised components of the momentum vector along the three axes.

Format 2

Format 2 has two additional columns:

x' y' z' x[mum] y[mum] z[m] charge[e] energy[GeV] z0[m] weight

z0 is the position along the z axis of the last interaction of the particle. weight is the weight factor, which depends upon the cross section biasing factor of the process in which the particle was generated and the weight of the parent particle.

History

OldFiles - click here

Files 13 and 14 16th April 2010

The number of primaries used to generate this file was N_p = 30130

The number of muons/antimuons per primary halo particle hitting the sampler at QD0 is (5.56 +/- 0.01) X 10^(-5). Assuming 2 X 10^(10) particles per bunch, and a halo population factor of 10^(-3), there are 1113 +/- 2 muons/antimuons per bunch (here +/- is the statistical uncertainty in the estimate of the mean).

Files 15 and 16 27th April 2010

Swapped layout.

The number of primaries used to generate this file was N_p = 12059

The number of muons/antimuons per primary halo particle hitting the sampler at QD0 is (2.274 +/- 0.09) X 10^(-5). Assuming 2 X 10^(10) particles per bunch, and a halo population factor of 10^(-3), there are 455 +/- 2 muons/antimuons per bunch (here +/- is the statistical uncertainty in the estimate of the mean). This is a 41% reduction compared to file 13.

NOTE

A bug meant that in all the previous files a sample of only a few hundred halo electrons was used. This has now been fixed and 37500 halo electrons are used in the files below.

Current files

Files 17 and 18 2nd February 2011

These files were generated using the same simulation as files 13 and 14. The statistics are increased, and a sample of 37500 halo electrons was used, instead of just a few hundred. The muons were recorded at a plane at the exit of QF1.

The number of primaries used to generate this file was N_p = 7.65E5 by repeating a sample of 3.75E4 halo electrons.

The number of muons/antimuons per primary halo particle hitting the sampler at the exit of QF1 is (4.96 +/- 0.12)E-5. Assuming 2E10 particles per bunch, and a halo population factor of 1E-3, there are 991 +/- 24 muons/antimuons per bunch (here +/- is the statistical uncertainty in the estimate of the mean).

Files 19 and 20 2nd February 2011

Here, the spoiler geometries are updated to the latest designs, as presented in WEPEB046, "Optimisation of the CLIC baseline collimation system", in the Proceedings of IPAC '10, Kyoto, Japan. The magnet settings, however, remain unchanged. Work is ongoing to include the optics optimisation in the simulation.

The number of primaries used to generate this file was N_p = 7.6E5 by repeating a sample of 3.75E4 halo muons.

The number of muons/antimuons per primary halo particle hitting the sampler at the exit of QF1 is (4.86 +/- 0.11)E-5. Assuming 2E10 particles per bunch, and a halo population factor of 1E-3, there are 972 +/- 21 muons/antimuons per bunch (here +/- is the statistical uncertainty in the estimate of the mean).

Files 21 and 22 31st May 2011

Muon spoilers and a tunnel filler were added. Factor 15 fewer muons hit the detector than files 19 and 20 above. For details see outline file below.

  • outline.dat: Outline of BDS with muon spoilers and a tunnel filler.

Files 23 and 24 15th June 2011

Muon spoilers only. Factor 10 fewer muons than files 19 and 20. For details see outline file below.

Note - results are preliminary and subject to change

Topic attachments
I Attachment History Action Size Date Who Comment
Unknown file formateps CLIC_bds_swap_from_ysp1.eps r1 manage 96.5 K 16 Apr 2010 - 11:17 LawrenceDeacon A diagram showing locations of components along the beam line. The betratron spoilers are omitted.
Unknown file formatgzip clic_v1_el_f1_01_02_11.dat.gzip r1 manage 8846.1 K 01 Feb 2011 - 11:43 LawrenceDeacon Muons at the exit of QF1. 2010 CLIC layout and collimator geometries. File format 1.
Unknown file formatgzip clic_v1_el_f2_01_02_11.dat.gzip r1 manage 10156.5 K 01 Feb 2011 - 11:45 LawrenceDeacon Muons at the exit of QF1. 2010 CLIC layout and collimator geometries. File format 2.
Unknown file formatgzip clic_v2_el_f1_01_02_11.dat.gzip r1 manage 8566.1 K 01 Feb 2011 - 11:45 LawrenceDeacon Muons at the exit of QF1. 2010 CLIC layout. Latest collimator geometries. File format 1.
Unknown file formatgzip clic_v2_el_f2_01_02_11.dat.gzip r1 manage 9683.4 K 01 Feb 2011 - 11:46 LawrenceDeacon Muons at the exit of QF1. 2010 CLIC layout. Latest collimator geometries. File format 2.
Texttxt corrected_outline.txt r1 manage 37.2 K 16 Apr 2010 - 14:09 LawrenceDeacon Outline of BDS from first spoiler YSP1
Texttxt muons_3m_upstream_qd0_e-_1500GeV.txt r1 manage 1067.0 K 18 Mar 2010 - 11:16 LawrenceDeacon Muons 3m upstream of the entrance to QD0 from 1500 GeV halo electrons hitting YSP1.
Unknown file formatdat muons_e-_1500GeV.dat r1 manage 3360.4 K 15 Mar 2010 - 15:53 LawrenceDeacon Muons at the entrance to QD0 from 1500 GeV halo electrons hitting YSP1.
Texttxt muons_e-_16_04_format1.txt r1 manage 1251.8 K 16 Apr 2010 - 14:04 LawrenceDeacon  
Texttxt muons_e-_16_04_format2.txt r1 manage 1500.3 K 16 Apr 2010 - 14:04 LawrenceDeacon  
Texttxt muons_e-_30_03.txt r1 manage 1365.4 K 30 Mar 2010 - 15:52 LawrenceDeacon Muons at the exit of magnet QF1 from 1.5 TeV halo electrons hitting first vertical spoiler ysp1
Texttxt muons_e-_30_03_format2.txt r1 manage 1636.2 K 13 Apr 2010 - 12:00 LawrenceDeacon extra data z0, weight
Texttxt muons_e-_swap_16_04_format1.txt r1 manage 23.5 K 20 Apr 2010 - 14:10 LawrenceDeacon  
Texttxt muons_e-_swap_16_04_format2.txt r1 manage 28.2 K 20 Apr 2010 - 14:07 LawrenceDeacon  
Texttxt muons_swap_e-_12_04_format1.txt r1 manage 15.3 K 13 Apr 2010 - 16:19 LawrenceDeacon Improved swapped BDS layout (layout produced by Rogelio Garcia). Format 1.
Texttxt muons_swap_e-_12_04_format2.txt r1 manage 18.3 K 13 Apr 2010 - 16:19 LawrenceDeacon Improved swapped BDS layout (layout produced by Rogelio Garcia). Format 2.
Texttxt muons_swap_e-_14_04_format1.txt r1 manage 34.3 K 16 Apr 2010 - 10:28 LawrenceDeacon Corrected layout. Starting at YSP1 (first spoiler)
Texttxt muons_swap_e-_14_04_format2.txt r1 manage 41.2 K 16 Apr 2010 - 10:28 LawrenceDeacon Corrected layout. Starting at YSP1 (first spoiler)
Texttxt muons_swap_e-_16_04_format1.txt r1 manage 34.3 K 16 Apr 2010 - 14:05 LawrenceDeacon  
Texttxt muons_swap_e-_16_04_format2.txt r1 manage 1500.3 K 16 Apr 2010 - 14:05 LawrenceDeacon  
Texttxt muons_swap_e-_27_04_format1.txt r1 manage 204.5 K 27 Apr 2010 - 17:00 LawrenceDeacon  
Texttxt muons_swap_e-_27_04_format2.txt r1 manage 244.9 K 27 Apr 2010 - 17:00 LawrenceDeacon Corrected low energy cutoff for electrons, positrons and photons.
Texttxt muons_swap_e-_30_03.txt r1 manage 442.0 K 09 Apr 2010 - 12:59 LawrenceDeacon Same as file 3 but with 'swapped' collimation sections
Texttxt muons_swap_e-_30_03_format2.txt r1 manage 529.1 K 13 Apr 2010 - 12:01 LawrenceDeacon extra data z0, weight
Unknown file formatdat outline.dat r2 r1 manage 101.3 K 15 Jun 2011 - 10:26 LawrenceDeacon With muon spoilers.
Texttxt spoilers_f1.txt r1 manage 2718.9 K 15 Jun 2011 - 10:23 LawrenceDeacon  
Texttxt spoilers_f2.txt r1 manage 3259.6 K 15 Jun 2011 - 10:23 LawrenceDeacon  
Unknown file formatdat spoilers_fillers_f1.dat r1 manage 1329.6 K 31 May 2011 - 22:15 LawrenceDeacon Distribution after muons spoilers added. Format 1.
Unknown file formatdat spoilers_fillers_f2.dat r1 manage 1596.9 K 31 May 2011 - 22:16 LawrenceDeacon Distribution after muons apoilers added. Format 2.
Texttxt swap_v1_outline.txt r1 manage 64.0 K 16 Apr 2010 - 10:20 LawrenceDeacon All components, positions and settings for the swapped beam line, v1
Texttxt swap_v2_corrected_outline.txt r1 manage 66.2 K 16 Apr 2010 - 10:29 LawrenceDeacon All components, positions and settings for the swapped beam line, v2. Corrected layout, starting at YSP1.
Texttxt swap_v2_outline.txt r1 manage 67.3 K 16 Apr 2010 - 10:20 LawrenceDeacon All components, positions and settings for the swapped beam line, v2
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Topic revision: r22 - 15 Jun 2011 - LawrenceDeacon

 
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