Alice experiment Goal and method



Yüklə 445 b.
tarix01.08.2018
ölçüsü445 b.
#64791



ALICE experiment



Goal and method

  • Goal and method

  • Detector

  • Overview of the electronics:

    • Trigger electronics
  • performance





Select events containing  pairs from J/ and  decay

  • Select events containing  pairs from J/ and  decay

  • Reject events containing only low-pt background muons (mainly from  and K decay)

  • About 8 muons in trigger detector per central Pb-Pb collisions

  • Cut on transverse momentum of muons:

    • pt,cut (J/)=1 GeV/c
    • pt,cut ()=2 GeV/c










The FEE basically consists of a discriminator stage followed by a shaper, without amplification stage.

    • The FEE basically consists of a discriminator stage followed by a shaper, without amplification stage.
    • The output signal must have a width of about 20 ns, less than the LHC bunch crossing interval of 25 ns.
    • specially designed Front–End Electronics Card based on a dual threshold technique to optimize the time resolution performance.


The FEE basically consists of a discriminator stage followed by a shaper, without amplification stage.

    • The FEE basically consists of a discriminator stage followed by a shaper, without amplification stage.
    • specially designed Front–End Electronics Card based on a dual threshold technique to optimize the time resolution performance.












BACKUP SLIDES

  • BACKUP SLIDES





Front-end Board characteristics



Each strip is connected at one end to a resistive termination and to a FEE channel at the other end.

    • Each strip is connected at one end to a resistive termination and to a FEE channel at the other end.
    • The FEE basically consists of a discriminator stage followed by a shaper, without amplification stage.
    • The output signal must have a width of about 20 ns, less than the LHC bunch crossing interval of 25 ns.
    • The FEE signals are sent in differential mode to the local trigger electronics through cables about 15 m long.




Beam tests: time resolution - II

  • ADULT provides two main advantages



time resolution

  • When RPC is operated at voltages close to the efficiency knee, sometimes the streamer pulse is delayed with respect to the initial electron avalanche started by the passage of the ionizing particle

  • This phenomenon determines a double peak in the time distribution of signals, which disappears by increasing the H.V.

  • The rise of the operating voltage, however, causes a deterioration of the cluster size.



3 levels :

  • 3 levels :

    • Local (x234)
    • Régional (x16)
    • Global
  • Trigger latency < 700 ns (see budget time slide)

  • The trigger participates in the ALICE L0 trigger



Position on MT1 (Xpos)

  • Position on MT1 (Xpos)

  • Deviation (Xdev)





Yüklə 445 b.

Dostları ilə paylaş:




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©muhaz.org 2024
rəhbərliyinə müraciət

gir | qeydiyyatdan keç
    Ana səhifə


yükləyin