mechanics foil frame and print anode inner cathode hood pressure control + he bag + target
DESCRIPTION
Status report on DC. Mechanics Foil Frame and Print Anode Inner cathode Hood Pressure control + He bag + target Electronic Schedule. Mechanics. 2. Foil. Order: a) first foil to check, 250 nm b) send 59 others up to now 3 iterations of a) Geometry OK - PowerPoint PPT PresentationTRANSCRIPT
2/9/2004 DC status - BVR 1
1. Mechanics
2. Foil
3. Frame and Print
• Anode
• Inner cathode
• Hood
4. Pressure control + He bag + target
5. Electronic
6. Schedule
Status report on DC
2/9/2004 DC status - BVR 2
1. Mechanics
2/9/2004 DC status - BVR 3
2/9/2004 DC status - BVR 4
2. FoilOrder: a) first foil to check, 250 nm
b) send 59 others
up to now 3 iterations of a)
Geometry OK
~ +.1% vertically, ~-.1% horizontally
Third foil
larger width of the non aluminized separations between the strips
smaller size of the aluminized reference crosses
It looks like if the etching was done in 2 sequences with a shift perpendicular to the strip by roughly a fifth of the separation.
2/9/2004 DC status - BVR 5
0
2000
4000
6000
8000
10000
12000
14000
16000
0 20 40 60 80 100
Series1
Series2
0
100
200
300
400
500
600
700
800
900
0 20 40 60 80 100
length of the strip
tota
l re
sis
tan
ce o
f th
e s
trip
side 1
side 2
0
50
100
150
200
250
300
350
400
450
500
0 20 40 60 80 100
Series1
Series2
the resistance of foil bands (~30 cm long and ~2 cm wide)
before etching [Ohm*cm] after etching [Ohm*cm]
foil2 2 .0 1.9 foil 3 1.5 > 18.0
standard aluminized Mylar foil 1.1
2 concentric electrodes (r =~1mm and 17 mm).
foil2 1.1 to 1.6 1.1 to 1.6 foil 3 .74 to 2.2 3.3 to 20 standard aluminized Mylar foil .71
1. interruptions, too thin
2. Ok ! Too thin
3. Many problems,Thicker
Resistivity
2/9/2004 DC status - BVR 6
a couloscope in nm at different positions of a sample)foil1 120, 120, 117
foil2 after: 112, 96, 70foil3 before: 188, 139, 131, 171foil3 after 255, 197, 201
Thickness
transparency
2/9/2004 DC status - BVR 7
3. Frame and Print
A) Anode1. First simultaneous use of carbon frame and print-> successful check of information
from the telegraph equation and units simulation (see later)
2. Experience about details of the procedure to built and equip anode frames
3. First iteration simulation of how the frame should be ordered to realize with mechanical tension what we finally want to have second order
4. Built in a always working Al prototype with cathode foil
5. Wires problem of other PSI groups solved
2/9/2004 DC status - BVR 8
3. Frame and Print
B) Inner cathode
c
Stretched carbon fibers(1000x d=6mm) and deformed ROHACELL
Carbon brings a factor 5-7
basis
wings
Carbon fibers
2/9/2004 DC status - BVR 9
Procedure under control
Actually at PSI last production turn to document precisely the size of deformations
PRODUCTION
Same iteration as anode
1. Good to 10-15 %
2. „linear“ matching with tension on carbon fiber wire
3. < 200 g/cm but as much as possible
Reihe1
Reihe3
-4.000
-2.000
0.000
2.000
4.000
6.000
8.000
10.000
12.000
Reihe4
Reihe5
2/9/2004 DC status - BVR 10
3. Frame and Print
C) Hood
2/9/2004 DC status - BVR 11
To do better: Stretch „vertically“ and fix the width
a) Modify the shape of the hood to have a larger flat surface to glue
b) Machine a foam structure in ROHACELL 30
c) Adapt the cathode foil procedureOnly minor modifications to the previously designed tools
Mounting of Hood foil
Largest height
Not disturbing the cell
DC report june_04,J.E.
Long design time
Long delivery time
2/9/2004 DC status - BVR 12
On the carbone fiber and foam structure
On the foil
Carbone fiber
Steel wires
On the frame
2/9/2004 DC status - BVR 13
pb
p Pa
bubbler
F0
Fi
Fo
Fo = a (p-pa) V = V0 + c (p-pb)
Fi - Fo = d(kVp)/dt =
k (dp/dt) (V0 + c (p-pb) + cp)
dp/dt ~ (Fi – a (p-pa) )/cp
a = 3 cc/(min*mbar) c = 588 cc/mbar
dp/dt = .2 mm / 10 bar
2/9/2004 DC status - BVR 14
-0.150
-0.100
-0.050
0.000
0.050
0.100
0.150
0.200
0.250
14:24 14:52 15:21 15:50 16:19 16:48 17:16 17:45
pi-pa [.1 mbar]
x left [mm]
y up [mm]
x right [mm]
gas in[cc/s]
~/20
~/2
2/9/2004 DC status - BVR 15
4. He bag + Pressure control
young positrons traverse 1 Foil
„Leaves“ space for TC
Cable duct is tight
More complicated than overall bag
2/9/2004 DC status - BVR 16
v
16x
He bag
WCHe
C2H6
He
Hermes, Belle (Openshaw,TRIUMF) + MKS
Too expensive, big size, magnetic
2/9/2004 DC status - BVR 17
v
15x
He bag
WCHe
C2H6
He
WC
1.3 g/bar on the chamber
1.7, [8.6,13.6] bar for 10 cm of He [He-ethane,Air] evt. 2 or 3 groups of chambers
~30 bar for 1m tube( radius= 2mm,1 cm**3/s of Air), 23 bar for He(50%),C2h6(50%)
Gas input in the chamber ~= 15 cm of tube with half diameter
Total gas impedance should not vary more than 20% to have healthy gas flow in all chambers
2/9/2004 DC status - BVR 18
Electronic
uncertainty on why no charge division effect seen on small prototype
-> bad matching of anode impedance on print impedance (correction out of range for print)
Program with telegraph equation and print unit simulation
Decoupling capacitor not optimized
Practically preamps survives HV breakdown of 2.1 KV ~ 3 pF
Tool ready to be used
Cables and preamps production sufficient to test correctly the Al prototype with anodes
2/9/2004 DC status - BVR 19
2.82 nF
.82 nF
Influence of decoupling capacitor
2/9/2004 DC status - BVR 20
Coming
• Test next foils …….• Test on old hood: to check principle and tools + scale of foil
deformation on pressure order Carbon Hood_0 (~7 weeks)• Last turn + Detailed measurement of elasticity and deformations of
inner cathode, final order (~ 5 weeks)• Sr-source run with DRS (not luxurious, 28 for 36 needed) of the Al-
prototype (C-anode frame + cathode foil 2) • -> confirm results of small DC for the 1:1 prototype• -> ev. Get a measured limit on the necessary cathode resistivity• 2 Russians (01/03/05 for 6 months)
2/9/2004 DC status - BVR 21
2002 2003 2004 2005
Test MilestoneAssemblyDesign Manufacturing
Full Prototype
Medium PrototypeCharge division & Cosmics
Full Detector (18 DC)
Drift Chamber
Full Prototype Beam test
Full Prototype
Charge division & Cosmics
Medium Prototype
Full Detector (18 DC)
outside insideCOBRA
Inside COBRA
Full Size Prototype
2/9/2004 DC status - BVR 22
2002 2003 2004 2005
Test MilestoneAssemblyDesign Manufacturing
Full Prototype
Medium PrototypeCharge division & Cosmics
Full Detector (18 DC)
Drift Chamber
Full Prototype Beam test
Full Prototype
Charge division & Cosmics
Medium Prototype
Full Detector (18 DC)
outside inside
COBRA
Inside COBRA
Full Size Prototype
2/9/2004 DC status - BVR 23
2005 2006
A.Hofer 1 1 1 1 1D.Fahrni 1 0.5 1 1 1L.Meier 0.5 0.5N.N.Meier 0.5 1 1 1Z.Hochmann 0.5 0.5 1Andrej K. 1 1Nicolas S. 1 1M.Schneebeli 1 1 1 1 1H.Nishiguchi 0.5 0.5 0.5 0.5 0.5M.Hildebrandt 0.5 0.5 0.5 0.5J.Egger 1 1 1 1 1
4.5 8 9 7 6