Mesure sur le detecteur PCB fin au 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
3000	0.06	3000	0.11
4000	0.09	3000	0.15	738731	370 hits during 64 seconds
5000	0.11	5000	0.14	738732	6700 hits during 90 seconds
6000	0.18	6000	0.14	738733	28182 hits during 90 seconds
7000	0.45	7000	0.21	738734	~ 1 Hz/cm2	118	90	4	76.27	3.92	3.39	1.67
7000	0.35	7000	0.18	738736	~ 1 Hz/cm2	95	73	1	76.84	4.33	1.05	1.05
7200	0.43	7200	0.21	738737	~ 1.6 Hz/cm2	272	218	17	80.15	2.42	6.25	1.47
7400	0.48	7400	0.21	738738	~ 2.4 Hz/cm2	286	230	48	80.42	2.35	16.78	2.21
7600	0.59	7600	0.27	738739	~ 3.6 Hz/cm2	288	240	92	83.33	2.20	31.94	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

738740

7600

86.30

4.02

36.99

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

738745	7600	126	112	101	88.89	2.80	80.16	3.55
738746	7000	118	99	74	83.90	3.38	62.71	4.45

Run of 7200 s

Run	HV	N trg	N seen	N 2 side	Eff	dEff	Eff_Y	dEff_Y
738747	6600	1077	408	265	37.88	1.48	24.61	1.31
738748	6800	1136	778	604	68.49	1.38	53.17	1.48
738749	7000	1137	925	771	81.35	1.16	67.81	1.39
738753	7100	1066	890	742	83.49	1.14	69.61	1.41
738750	7200	1098	948	833	86.34	1.04	75.87	1.29
738754	7300	1157	1008	874	87.12	0.98	75.54	1.26
738751	7400	1138	1023	902	89.89	0.89	79.26	1.20
738755	7500	1087	966	860	88.87	0.95	79.12	1.23

Test with 505 threshold

— DAQ user 2017/12/13 11:20

738752

700

452

372

296

82.30

1.80

65.49

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 $\epsilon_2$	< $\Delta T$ >	$\sigma \Delta T$
738747	6600	6832	1077	405	263	37.60	1.48	24.42	1.31	-0.59	0.653
738748	6800	7039	1136	777	603	68.40	1.38	53.08	1.48	-0.28	0.583
738749	7000	7246	1137	924	770	81.27	1.16	67.72	1.39	-0.09	0.601
738750	7200	7453	1098	943	830	85.88	1.05	75.59	1.30	0.01	0.618
738751	7400	7660	1138	1015	901	89.19	0.92	79.17	1.20	0.00	0.632
738753	7100	7349	1066	890	742	83.49	1.14	69.61	1.41	-0.03	0.619
738754	7300	7556	1157	1010	874	87.29	0.98	75.54	1.26	0.05	0.648
738755	7500	7763	1087	969	860	89.14	0.94	79.12	1.23	0.05	0.724