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nouvelle_mesure_pcb_fin_cern

Mesure sur le detecteur PCB fin au CERN

DAQ user 2017/12/08 16:27

Resume

On a d'abord travaille la mise a la masse pour diminuer le bruit. On arrive a une situation a peu pres correcte (HV 100V)

Quand on teste l'injection on a des resultats bizarres du a des problemes sur le circuit d'injection

On teste l'injection 5 pC sur une piste + scope ==⇒ Defaut d'adaptation !!!!!!

On retrouve les ratios du PCB epais:

  • Cote injection 47.2
  • Cote oppose 31.7

Recopier ici le plot du scope

On arrete les mesures d'injection car le circuit d'injection est plein de faux contacts

Mesure de l'impedance au capacimetre

2 MHz

  • Open

Cp= 172 pF

Gp= 960 microS

  • Closed

Ls= 550 nH

Rs= 530 mOhm

DONC 56 Ohm d'impedance caracteristique

Mesure de signaux

On ne pût pas faire de mesure d'injection vendredi dernier

Apres un piedestal je corrigeai le DAC6B canal 10 ⇒ State FE2_24CH_4

Il faut donc désormais exécuter

 daqcontrol --daq-downloaddb --dbstate=FE2_24CH_4
 daqcontrol --daq-configure

dans le script startnorm qui se trouve sur /home/acqilc sur lyosdhcal10

daqcontrol --daq-downloaddb --dbstate=FE2_24CH_4
daqcontrol --daq-configure
daqcontrol --trig-spillof --clock=20000
daqcontrol --trig-spillon --clock=200000
daqcontrol --daq-setvth --vth=507
daqcontrol --trig-spillreg --value=4

Un run de pedestal avec 20 V sur les gap est le 738730

On doit pouvoir descendre le seuil a 505 sur ce FE#2

DAQ user 2017/12/12 14:12

Gas is Ok

HV ramp

Roughly 550 muon per hour

HV top I top HV bot I Bot run Noise obs. N trg N seen N 2 side Eff dEff Eff_Y dEff_Y
30000.0630000.11
40000.0930000.15 738731 370 hits during 64 seconds
50000.1150000.14 738732 6700 hits during 90 seconds
60000.1860000.14 738733 28182 hits during 90 seconds
70000.4570000.21 738734 ~ 1 Hz/cm2 11890476.27 3.92 3.39 1.67
70000.3570000.18 738736 ~ 1 Hz/cm2 9573176.84 4.33 1.05 1.05
72000.4372000.21 738737 ~ 1.6 Hz/cm2 2722181780.15 2.42 6.25 1.47
74000.4874000.21 738738 ~ 2.4 Hz/cm2 2862304880.42 2.3516.78 2.21
76000.5976000.27 738739 ~ 3.6 Hz/cm2 2882409283.33 2.2031.94 2.75

Weird TDC profile for noise

Did we break something on Friday? No reason to have so few signal on half of the strips for noise.

!!! The efficient side is the OPPOSITE side to the trigger !!!

Start real scan 2 h data taking with steps of 200 V from 7600 to 6400 V

738740760073632786.30 4.0236.99 5.65

DAQ user 2017/12/12 18:24

lyosdhcal10 is not reachable anymore . No idea what's going on

DAQ user 2017/12/12 19:08

Elena checked all the connection. Once FEB is replugged we got equivalent noise on all strips and the efficiency changed. I do not expect to have 80 % efficiency on both side at 7 kV because since the strips were most probably unconnected on the narrow side the charge seen on the other side was double….

Small runs of 900 s

738745760012611210188.89 2.8080.16 3.55
7387467000118997483.90 3.3862.71 4.45

Run of 7200 s

Run HV N trg N seen N 2 side Eff dEff Eff_Y dEff_Y
7387476600107740826537.88 1.4824.61 1.31
7387486800113677860468.49 1.3853.17 1.48
7387497000113792577181.35 1.1667.81 1.39
7387537100106689074283.49 1.1469.61 1.41
7387507200109894883386.34 1.0475.87 1.29
73875473001157100887487.12 0.9875.54 1.26
73875174001138102390289.89 0.8979.26 1.20
7387557500108796686088.87 0.9579.12 1.23

Test with 505 threshold

DAQ user 2017/12/13 11:20

73875270045237229682.30 1.8065.49 2.24

No significant effect

now our gas:

  • iC4H10 = 4.92%,
  • DP = 3.3degC - in gas rack;
  • in lab 904 T=23.1 degC
  • P=965 hPa;
  • gas flow: 2.5 l/hr;
  • frequency of bubbles: BOT=2.6 Hz,
  • TOP = 1.1. Hz

$$ HV_{app}= HV_{eff} \times ( (1-\alpha)+\alpha \times \frac{P}{P0} \frac{T0}{T}) $$

with $\alpha$ =0.8 , P0=990 mbar T0=293K

Fig. 1: Efficiency curve from previous runs in function of effective HV. Blue is trip efficiency, orange (X,Y) efficiency

New analysis

Efficiency studies

Run HV applied HV eff N trigger N strip N 2 Strip $\epsilon$ (%) d$\epsilon$ $\epsilon_2$ (%) d$\epsilon_2$ <$\Delta T $> $\sigma \Delta T$
73874766006832107740526337.60 1.4824.42 1.31-0.590.653
73874868007039113677760368.40 1.3853.08 1.48-0.280.583
73874970007246113792477081.27 1.1667.72 1.39-0.090.601
73875072007453109894383085.88 1.0575.59 1.30 0.010.618
738751740076601138101590189.19 0.9279.17 1.20 0.000.632
73875371007349106689074283.49 1.1469.61 1.41-0.030.619
738754730075561157101087487.29 0.9875.54 1.26 0.050.648
73875575007763108796986089.14 0.9479.12 1.23 0.050.724

Fig. 2: Efficiency curve from previous runs in function of effective HV. Blue is strip efficiency, yellow (X,Y) efficiency

Measured distance at different HV applied

Fig. 3: Delta T 6600 V

Fig. 4: Delta T 6800 V

Fig. 5: Delta T 7000 V

Fig. 6: Delta T 7100 V

Fig. 7: Delta T 7200 V

Fig. 8: Delta T 7300 V

Fig. 9: Delta T 7400 V

Fig. 10: Delta T 7500 V

nouvelle_mesure_pcb_fin_cern.txt · Dernière modification: 2017/12/18 10:48 par DAQ user