160 likes | 285 Views
Status report MEG DC 13/2/2006. Foil, cathode, hood, anode DC1 tests and measurements Preamplifiers Cables, connectors, cable panels, splitter + sum Cable duct, DC support, minibag Tests and Schedule. All Foils delivered : resistance tested by REPIC : geometry checked
E N D
Status report MEG DC 13/2/2006 • Foil, cathode, hood, anode • DC1tests and measurements • Preamplifiers • Cables, connectors, cable panels, splitter + sum • Cable duct, DC support, minibag • Tests and Schedule
All Foils delivered : resistance tested by REPIC : geometry checked New polyimide: UPILEX stronger, less sensitive to humidity
Cathode : delivered after some discussion about planarity Hood: first 2 delivered for check, OKgiven for the 16 others Anode: delivered
DC1 ASSEMBLED .1 mm precision to frame referencepointsreached for anode, cathode and hood
DC1 ASSEMBLED • Production and mounting stopped to check HV-print-C edge stability (go to DC2) • foil measurement epoxided C-fiber mount cathode test Hood first delivery + mount • Simple HV test, HV-preamp test, set start value of parameters ( potential wire Voltage, ..) (go to DC2) • Read out(go to DC2)
More direct measurement to determine necessary pressure stability : • Gas outlet of DC in simple bag with same tubes as to manifold • source at a fix point in the middle of the surface • Vary flux through the chamber (0 to 50 sccm) 0 to 3 Pa and measure amplification variation with the current in the chamber • CONFIRM DIRECT MEASUREMENT OF CHAMBER „EXPANSION“ • For sudden change (door, ..) • no change in pV (flow in = flow out) 2 mbar in He bag .2% in pressure compensated by .2% in Volume = .1 mm = 1. Pa in (He bag-DC) • b) For change over 2 mbar at the rate of storm for 20 l ~ 2.6 cc/secflow controller (DAC) 1 Hz correction per second < 1 Pa = .2 cc/secMKS 1179B at 200 sccm precise to .7% = .025 cc/sec • c) Diff. Pressure to be controlled < 1 Pawith range of 1 mbar, MKS 120AD .25% .25 Pa
5. Gas pressure control Flow controller Flow controller He pump 1400 l .0 to .2 bar DC 16 x 1l < 500 Pa To Air 50% He + 50% C2H6 PDC PHe Flush in ~2 h ~ 150 sccm Storm ~ 500 Pa in/10 min = 8 Cc/min >1.8 bar PHe-PDC < 1Pa .2 Cc, 14 Cc Dif. Pressure sensor
Preamplifiers : With 6 V supply and 5 V regulator on the preamp chip input protection diode for 2.2 kV break down ~ 100, with old dimensions ~ 150, ~1.5 mm shorter and inclined connectors (5 different types) production continues Last prints and elements partly here, connectors offered with cables Tests with DRS and DC1 + DC_Al + small DC factor 2 ? Preamplifier cooling (Malte) Some like it not hot and water cooled !!
S Cables, connectors, cable panels, splitter + sum 1750 between ~250 cm and ~400 cm + 1750 ~750 cm long Precimation coaxial as in magnet , offered Suhner coaxial soldered on 16 channel print, attenuation + ~6 db Erni 34x2 pins (SMD?) connectors for 16 channels Splitter (1 kW) + S ampli
Background in LXe from central part of cable duct (Hajime,..) number of g background event (low threshold) Distance to current position [cm]
To larger radius Small level arm (near TC) Measurement by survey group of exact edgeshape at COBRA’s smaller radius ( being analyzed) Later measure welding circle at transition [edge – inner Cylinder] ( fix shape of DC Al fixing parts)
minibag • Non negligible effect on DC precision because of additional multiple scattering • Effect smaller near the target or near the DC both technically dangerous • Minibag is designed and will be constructed as test bag for: • tests with a few DC • Study of foil mechanical resistance
DC tests • HV test with assembled DC : [anode prints, parameters for pressure behavior] • HV test with preamps and DRS with Sr90 and cosmics:[ preamps, DRS,..] • 6-11 April : test in pE(M)1 with minimal ionizing p (>150 MeV/c) or e 50 MeV/c) 1 DC + Al-DC[preamp, DRS, DC calibration, resolution,…] • 11-16(24) May : test in Cobra, Field on + e+beam with < 3 DC’s[DC behavior in Cobra background , 511 keV] • Eventually second test in pE1 with more DC [ better DC calibration]
? ?
? ? ?
Manpower Person jan.-mar. 2006 apr.-jun. 2006 Johny 100% 100% Malte 90% 80% Andi 100% 100% Dieter 100% 100% Florian 100% 100% Matthias 40% 40% Hajime 60% 60% Zdenek 40% 40% Ueli 30% 30% ------ ------ 6.6 6.5