1 / 19

Shielded timing RPCs for the HADES collaboration

H.Alvarez-Pol 1 , R.Alves 2 , A.Blanco 2 , N.Carolino 2 , J.Eschke 3 , R.Ferreira Marques 2,4 , P.Fonte 2,5 , A.Pereira 2 , J.Pietraszko 6 , J.Pinhão 2 , A.Policarpo 2,4 , J.A. Garzón 1 , Diego González-Díaz 1 , J.Stroth 3,7

louie
Download Presentation

Shielded timing RPCs for the HADES collaboration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. H.Alvarez-Pol1, R.Alves2, A.Blanco2, N.Carolino2, J.Eschke3, R.Ferreira Marques2,4, P.Fonte2,5, A.Pereira2, J.Pietraszko6, J.Pinhão2, A.Policarpo2,4, J.A. Garzón1, Diego González-Díaz1, J.Stroth3,7 1 - GENP, University of Santiago de Compostela, 2 – LIP, Coimbra, 3 - GSI, Darmstadt, 4 - Departamento de Física, Universidade de Coimbra, 5 – ISEC, Coimbra, 6 - Smoluchowski Institute of Physics, Jagiellonian University of Cracow. 7 - Institut für Kernphysik, Johann Wolfgang Goethe­Universität Frankfurt. [Thanks to M. Golubeva for preparing the plots of AuAu@1.5-8GeV & CC@2-8GeV] Shielded timing RPCs for the HADES collaboration Diego González-Díaz GENP, Universidad de Santiago de Compostela for the HADES Collaboration

  2. THE HADES SPECTROMETER Beam line SIDE VIEW Proposed RPC wall UPSTREAM VIEW

  3. FRONTAL VIEW OF THE RPC WALL 170 cm 140 cm 40 cm

  4. HADES REQUIREMENTS Requirements for an RPC wall as a TOF detector for HADES: -Adequate granularity. -Time resolution below 100 ps. -Good behaviour at rates of few hundreds of Hz/cm2. (attainable rates for AuAu collisions). Some possible shortcomings: -Crosstalk between neighbouring cells. -Dealing with fast and slow particles simultaneously.

  5. EXPERIMENTAL SETUP

  6. EXPERIMENTAL SETUP Gas admixture: 98.5% C2H2F4 + 1% SF6 + 0.5 iso-C4H10

  7. EXPERIMENTAL SETUP DOWNSTREAM VIEW UPSTREAM VIEW

  8. PHYSICAL ENVIRONMENT

  9. PHYSICAL ENVIRONMENT L L A RPC B C Trigger = A*B*C δ(Tscin) = 50 ps

  10. CHARGE-TIME CORRELATION Good agreement with a 2-segment linear fit (!)

  11. CHARGE-TIME CORRELATION Uncorrected Corrected

  12. HOMOGENEITY

  13. BEHAVIOUR WITH RATE Future (600Hz/cm2) Present (20Hz/cm2)

  14. BEHAVIOUR WITH RATE

  15. CROSSTALK main neighbour Coincidences of signals in neighbouring cells

  16. CROSSTALK Coincidence between hits in neighbouring cells Particle pairs generated locally Particle pairs from target

  17. POSITION RESOLUTION Maximum non-linearity = 2.5 mm Non-linearity r.m.s = 1.5 mm

  18. CONCLUSIONS • A multichannel RPC prototype able to work in an ion fragmentation environment has been tested. • Time resolution: δ(T) = 67 ps [ + 47ps · rate/(kHz/cm2) ] • Position resolution better than δ(x)= 5.5 mm. Max non-linearity =2.5mm • Global efficiency: ε = 87% - 15% · rate/(kHz/cm2) • High homogeneity allows to get T-Q calibration parameters from a single position. • Shielding between cells keeps crosstalk below the level of 0.4 %. • Coincident hits in neighbouring cells do not induce any degradation in time resolution. • No signficant increase in streamers due to the presence of low energy particles

  19. 2 layers (with overlapping) vs 1 layer: • Disadvantages: • Wider cells for same number of channels => less granularity for Trigger 1 • Increase of material in front of the preshower detector • Worst y-coordinate resolution (wider cells) (*) • More flexibility, more complex design. • Advantages: • Dead zones highly reduced • Redundance • Autocalibration possible (to be tested) • Wider cells => Easier construction • Better isolation between neighbour cells (bigger gaps between cells) • More separation between box and active cell • More space for cabling • (*) Better y-coordinate resolution (cells overlapping)

More Related