MEG DC HV supply preamplifier noise and DRS

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MEG DC • HV supply preamplifier noise and DRS Input attenuation • protection in

MEG DC • HV supply preamplifier noise and DRS Input attenuation • protection in pure He new print • gas regulation, DC tightness, He-C 2 H 6 ratio • N bag • Calibration • schedule 3/12/2021 DC_status, Je 1

HV supply < 100 V oscillations OK Capacitors +DC charge loading 8 x 2

HV supply < 100 V oscillations OK Capacitors +DC charge loading 8 x 2 channels for dec-run Tests Noise – filter Optimize ramping Recovery, isolators polarizing time 3/12/2021 DC_status 2

preamplifier noise and DRS Input attenuation s of 400 first DRS channels [m. V]

preamplifier noise and DRS Input attenuation s of 400 first DRS channels [m. V] For physical big pulse Ratio e+/big pulse const For « edge » big pulse At least rate increas with HV sqrt([6 V on]2 - [6 V off]2) 3/12/2021 DC_status Anode number 3

DC Current-slit behavior OK Noise important Max current at 1700 V : ~5 m.

DC Current-slit behavior OK Noise important Max current at 1700 V : ~5 m. A May be 1780 necessary (first run 2000 V : 60 m. A) 3/12/2021 DC_status 4

Noise 1. Much larger than in lab 2. Much larger than first measurement in

Noise 1. Much larger than in lab 2. Much larger than first measurement in PE 5 3. Fast contribution (see Matthias) already found in HV supply as used in December 2007 run 4. « slow » component { 1 -2 ms) needs more work 3/12/2021 DC_status 5

protection in pure He Capacitors, edges, resistance in pure He (< 2% impurities) Imbed

protection in pure He Capacitors, edges, resistance in pure He (< 2% impurities) Imbed elements in Araldit, stable homogenous no temperature effect < 65 0 Threebond white and grey , needs humidity temperature effects already at 55 0 Edges better with next print 3/12/2021 DC_status 6

new print Near wing frame, protection longer Increase distance Carbon frame to HV lines,

new print Near wing frame, protection longer Increase distance Carbon frame to HV lines, not to suffer from Threebond „bad“ isolator properties 3 layers with wenn possible HV line in the middle layer 3/12/2021 DC_status 7

[Pa] gas regulation and DC tightness Pressure sensors S 1 S 2 Dpf DC‘s

[Pa] gas regulation and DC tightness Pressure sensors S 1 S 2 Dpf DC‘s Flux in out Dp manifold Dp/(Flux in+ Flux out) [Pa/(cc/min)] Consistency Dp/(Flux in+ Flux out) constant (S 1+S 2)/2 Dpf << Dp 3/12/2021 DC_status 8

12 min Tightness 4 good Ln Dp 2 not so good 2 bad 8

12 min Tightness 4 good Ln Dp 2 not so good 2 bad 8 DC connected to manifolds Stabilize at or Ok if not Flux out (with Flux in = 50 cc/min) DC‘s (not consistent with viscosity air-He) 3/12/2021 (S 1+S 2)/2 DC_status 9

C 2 H 6 If diffusion 1/180 negligible If leak ½ . 36 cc/min

C 2 H 6 If diffusion 1/180 negligible If leak ½ . 36 cc/min He. 09 p/min 16 DC, . 5 atm . 72 cc/min 40 cc/min 2 % Diffusion of He through Mylar 12 mm 1/2 atm 16 x 1450 cm 2 4. 6 cc/min 3/12/2021 DC_status 10

He-C 2 H 6 Ratio dependence 1850 V 43% He, 50% He, 55. 6%

He-C 2 H 6 Ratio dependence 1850 V 43% He, 50% He, 55. 6% He . 79 1. 03 1. 3 3/12/2021 < 2 % stability, reproducibility DC_status 11

Sensor of He fraction in He-C 2 H 6 mixture 1. Gas system in

Sensor of He fraction in He-C 2 H 6 mixture 1. Gas system in Lab 2. Understand calibrate system perfectly 3. Calibration of He content sensor or better suited sensor 3/12/2021 DC_status 12

1. Cable duct radius – 2 to 3 mm 2. Modify shape of C

1. Cable duct radius – 2 to 3 mm 2. Modify shape of C – supports 2. 5 mm 3. adapt new manifold to 1) 3/12/2021 4 DC_status 13

Calibration methods • lab aquarium ( DRS + cables for 2 DC) 1. Mn

Calibration methods • lab aquarium ( DRS + cables for 2 DC) 1. Mn 54 triggered ( 5. 9 ke. V, 835 ke. V photo peak) 2. Sr 90 triggered (< 2 Me. V b) 3. Cosmic m triggered Na. I DC • Lab support ( DRS + cables for 2 DC) (check all channels correctly connected and correlated anode up, anode down, cathodes) 1. Mn 54 triggered (for the temporarily outer DC) 2. Sr 90 not triggered 3. Cosmic m (triggered ? , complicated) • COBRA (not closed) (check all channels correctly connected and correlated anode up, anode down, cathodes) 1. DC Sr 90 not triggered 2. Cosmic m triggered 3/12/2021 DC_status 14

Cosmic Tokio m Scintillators COBRA Xe Na. I DC 3/12/2021 DC_status 15

Cosmic Tokio m Scintillators COBRA Xe Na. I DC 3/12/2021 DC_status 15

Schedule beginning 2007 Feb 01 Feb 02 Mar 1 Mar 2 Mai 01 Mai

Schedule beginning 2007 Feb 01 Feb 02 Mar 1 Mar 2 Mai 01 Mai 02 Jun 01 Jun 02 4 weeks 12 weeks construction 13 weeks (Tightness) Lab test Sr 90, Mn 54, cosmic, all triggered mount on support (Sr 90 , self trigger, Mn 54 trigger) (triggered cosmic m’s ’ ? ) mount in Cobra (Sr 90 for , self trigger) (triggered cosmic m ‘s ? ) Cathode + Hood Apr 01 Apr 02 Anode ( new prints) „N bag“ Jul 01 test on support test in COBRA 3/12/2021 DC_status 16

New anodes largest time consumer (production rate known) Adapt to N bag conditions, New

New anodes largest time consumer (production rate known) Adapt to N bag conditions, New manifolds in optimized position New hood and cathode frame : Andrei and Nicolai mostly done Replace anodes on DC 04 t 0 DC 11, construct 8(10) new DC LV+HV cable labeling + mount: Test in aquarium with gas regulation, mount and test on support of modified and new DC Transport, and insert of support with 16 DC and TC+N bag in COBRA Test cabling in COBRA 3/12/2021 DC_status 17

3/12/2021 DC_status 18

3/12/2021 DC_status 18