LHC (SSC) - PowerPoint PPT Presentation

About This Presentation
Title:

LHC (SSC)

Description:

LHC (SSC) Byung Yunn CASA Parameters Type: Synchrotron Circumference: 26.659 (82.944) km Proton energy: 7.7 (20) TeV Bunch length: 7.5 (6 to 7.5) cm Energy spread: 1 ... – PowerPoint PPT presentation

Number of Views:98
Avg rating:3.0/5.0
Slides: 17
Provided by: derb152
Learn more at: https://casa.jlab.org
Category:
Tags: lhc | ssc | effects | radiation

less

Transcript and Presenter's Notes

Title: LHC (SSC)


1
LHC (SSC)
  • Byung Yunn
  • CASA

2
Parameters
  • Type Synchrotron
  • Circumference 26.659 (82.944) km
  • Proton energy 7.7 (20) TeV
  • Bunch length 7.5 (6 to 7.5) cm
  • Energy spread 1.05e-4 (0.5e-4)
  • Transverse emittance 3.75 (1.0) µm
  • Longitudinal emittance 2.5 (0.233) eV-s

3
continued
  • Protons per bunch 1.0e11 (7.3e9)
  • Average beam current 850 (73) mA
  • Number of bunches 4725 (17100)
  • RF frequency 400.8 (374.74) MHz
  • RF voltage 16 (20) MV
  • Synchrotron tune 0.00157 (0.0019)
  • Momentum compaction 2.94e-4 (2.23e-4)

4
continued
  • Nominal full crossing angle 200 (75) µrad
  • Bunch spacing 15 (16) ns
  • Beta star 50 (50) cm
  • Beam-beam tune shift 0.0032 (0.00084)
  • Luminosity (/cm2-s ) 1.65e34 (1.0e33)
  • Number of interaction points 3 (4)
  • Synchrotron radiation power (per beam) 9.1 (9.1)
    kw

5
Injectors (LHC)
  • 50 MeV proton linac (180 mA for 7 µs), injected
    into 4 PS booster rings
  • PS booster accelerated in one bunch up to 1.4
    GeV, PS accepts eight 200 ns long bunches
  • 26 GeV PS (1/11 of SPS) debunched and rebunched
    at 26 GeV to 1.0e11 protons per bunch (emittance
    3 µm, bunch length 9 ns)
  • 450 GeV SPS (7/27 of LHC) 36 SPS beam pulses to
    fill one LHC channel.

6
Injectors (SSC)
  • 600 MeV H- linac 125 m, RF Freq 49.5 MHz
    (RFQ), 445 MHz (DTL), 1336 MHz (SCL)
  • 8 GeV LEB 250 m, RF Freq 49.5-62.0 MHz
  • 100 GeV MEB 1.9 km, RF Freq 62.5 MHz
  • 1 TeV HEB (Superconducting) 6 km, RF Freq 62.5
    MHz
  • Average current (mA) 3.9 (Linac), 99 (LEB), 92
    (MEB), 87 (HEB)

7
Collider ring (LHC)
  • Built on top (1.21 m) of LEP and has eightfold
    symmetry
  • Two beam channels in the same magnet
  • 10 Tesla dipole field (4 to 6 Tesla available)
  • Can be used to collide ions
  • Number of arcs 8
  • Number of interaction regions 8 (3 collision and
    2 utility)

8
Collider ring (SSC)
  • Two rings separated vertically (0.7 m)
  • Dipole field 6.6 T
  • Quad in arcs 212 T/m
  • Interaction regions (IR) are arranged in 2
    clusters (East and West) for cost effectiveness
  • 4 IRs in each cluster and each IR is 2.4 km long
  • Clusters are joined by arcs of 11.7 km radius

9
Lattice (LHC)
  • Two beam channels in the same plane (18 cm
    separation in arcs) and cross at eight points.
  • Eight 25 FODO cells (98 m long and phase advance
    of 90 deg per cell) per ring
  • Four 9 m long dipoles and one 3 m quad in a half
    cell
  • Beta in arcs max 166 m, min 29 m
  • Dispersion in arcs max 1.86 m, min 0.9 m

10
continued
  • Working point (71.28, 70.31)
  • Insertion 886 m long and phase advance in each
    plane by 2.5 units
  • Chromaticity correction sextupoles next to the
    main quads, powered in 2 families
  • Linear aperture 4 mm

11
Lattice (SSC)
  • FODO cell 192 m long and phase advance of 60 deg
  • Five 16.5 m long dipoles and one 3.3m arc quad in
    each half cell
  • Eight 42 cells per ring
  • Beta in arcs max 332 m, min 111 m
  • Dispersion in arcs max 3.92 m, min 2.36 m
  • Natural chromaticity -204

12
continued
  • Working point (78.27, 78.28)
  • Chromaticity correction sextupoles next to the
    main quads, powered in 2 families
  • Linear aperture 5 mm

13
Collision IR (LHC)
  • 40 m free space between final quad triplets
  • Beta star can be tuned from 0.5 m to 15 m
  • Beta max 4 km
  • Beam radius at IP 15 µm
  • Beam divergence at IP 30 µrad

14
Collision IR (SSC)
  • 40 m free space between final quad triplets
  • Beta star 0.5 m
  • Beta max 8 km
  • Beam crossing angle at IR 75 µrad, but can vary
    from 0 to 150 µrad

15
Collective Effects (LHC)
  • Beam lifetime 26.5 h
  • Luminosity lifetime 11 h
  • IBS emittance growth time 100 h (horizontal), 60
    h (longitudinal)
  • Longitudinal microwave and transverse mode
    coupling instability are potential dangers.
    Coupled bunch instabilities require active
    feedback systems to control.

16
Collective Effects (SSC)
  • Beam lifetime 39000 h
  • Luminosity lifetime 24 h
  • IBS emittance growth time 126 h (horizontal),
    277 h (longitudinal)
  • Relatively safe from single bunch instabilities.
    Coupled bunch instabilities require active
    feedback systems to control.
Write a Comment
User Comments (0)
About PowerShow.com