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29 ottobre 2007 Torporkov visit
Finned Tube to increase target density?
Openable cell for p↑p↑
Ideas to increase cell thickness
Test on the finned Injection Tube
Ciullo G.
29 ottobre 2007 Torporkov visit
The openable cell
• Openable Cell to inject pbar @ AD
Y = 100, x = 50 mm
• Closed cell, square 10x10 mm,
5 m teflon foil.
Sampling tube
Injection Tube
29 ottobre 2007 Torporkov visit
Estimation of the target thickness• Thickness (tc) of the cell
• tc [atom/cm2]
• Cell Geometry: square 10x10 mm, length 400 mm
– IHERMES-ABS = 6.5 • 1016at/s then tc=8.81 • 1013at/cm2
• Some ideas “appear” in order to increase tc?!
2C
tot
LItc
TubeEstBRPABSLL CCCC .2/2/totC
cmin unit length
3.51sl
4.34
'-12
s
l
sl
AA
M
TC
3,94 3,94 5,83
04,181,41
32,11
1
1,04
29 ottobre 2007 Torporkov visit
Lower conductance thicker Target• Lowering the ABS injection Tube Temperature
Target thickness vs ABS injection tube temperature
6
7
8
9
10
11
12
25 50 75 100 125 150 175 200 225 250 275 300 325
ABS feeding tube Temperature [K]
Inte
gra
ted
tar
get
th
ickn
ess
[10
13 at
om
/cm
2 ]
20%
30%
10%
29 ottobre 2007 Torporkov visit
Lower conductance thicker Target• Longer ABS injection Tube
Target thickness vs ABS tube length
6
7
8
9
10
11
12
8 10 12 14 16 18 20 22
ABS feeding tube Length [cm]
Inte
gra
ted
tar
get
th
ickn
ess
[10
13 at
om
/cm
2 ]
10%
20%
29 ottobre 2007 Torporkov visit
Lower conductance thicker Target• ABS injection Tube with fins
cmin unit length
3.51sl
4.34
'-12
s
l
sl
AA
M
TC
Finned tube
8,00E+13
8,50E+13
9,00E+13
9,50E+13
1,00E+14
1,05E+14
1,10E+14
0 5 10 15
Number of fins
thic
kn
es
s (
at/
cm
q) 18 %
23 %AI 'Incoming atoms
Outcoming atoms
29 ottobre 2007 Torporkov visit
Finned tubes
29 ottobre 2007 Torporkov visit
Test on the finned tubes
Q = (Pcal-P cv) Ccal = (Pcv-P RF) Ccv
29 ottobre 2007 Torporkov visit
Measure of Ccal
• Misura di Ccal
• Evacuazione di Vcal da Ccal
. inoltre ;
cal
cal
cal
calcalcal V
V
C
CVC
0 20 40 60 80 1002
3
4
5
6
7
8
9
Data: aug17Cmeas_PbmModel: ExpDec1Equation: y = A1*exp(-x/t1) + y0Weighting: y Instrumental Chi^2/DoF = 0.09545R^2 = 1 y0 0.23024 ±0.01451A1 8.63199 ±0.01113t1 69.76054 ±0.24462P
bm (
mba
r)
time (min.)
Pbm ExpDec1 fit of aug17Cmeas_Pbm
29 ottobre 2007 Torporkov visit
Measured of Q calibrated
6,0x10-5 8,0x10-5 1,0x10-4 1,2x10-4 1,4x10-4 1,6x10-4 1,8x10-4 2,0x10-4
4,0x10-4
6,0x10-4
8,0x10-4
1,0x10-3
1,2x10-3
1,4x10-3
1,6x10-3
inear Regression for Qcalc0fins230_qCAL:Y = A + B * XWeight given by Qcalc0fins230_ErrQcal error bars.
Parameter Value Error------------------------------------------------------------A -7,2146E-5 1,96151E-6B 8,28848 0,01727------------------------------------------------------------
R SD N P------------------------------------------------------------0,9999 6,72786 3 0,00892------------------------------------------------------------
Qca
lib (
mb
ar
l/s)
Pcv
(mbar)
qCAL Linear Fit of Qcalc0fins230_qCAL
Calibrated througput measured with a 1% error
0 fins for 23 august
Q calibration curve derived for all finned tubes
29 ottobre 2007 Torporkov visit
Fixing in mind problems
• We can measure – The Qincoming is well
calibrated measurement
– Then derive the tc
• To derive the tc, from data
» We need Qincaming (2%)
And
» Coutcoming (30%)
29 ottobre 2007 Torporkov visit
I measured and see MC simulation
0 2 4 6 8 10 126,5x10-4
7,0x10-4
7,5x10-4
8,0x10-4
8,5x10-4
9,0x10-4
9,5x10-4
1,0x10-3
1,1x10-3
1,1x10-3
Q a
tom
ic b
ea
m (
mb
ar
l/s)
Number of fins
Q atomic beam measuredQ normalized as A
0 and derived as Q~A
29 ottobre 2007 Torporkov visit
Surviving atomic beam
29 ottobre 2007 Torporkov visit
s
l
A
A
sl
AA
M
TC
-1
0
2
13.51sl
4.34
'
Ccv measured and calculated
%]30 of [
%]2 of [
4.2 error
err
P
QC
cv
calmeas
Next step: use the baratron to measure PCV ?!
29 ottobre 2007 Torporkov visit
Thickenss of the cell
2C
tot
LItc
29 ottobre 2007 Torporkov visit
Conclusions
• To increase the target density– Lower temperature of ABS injection tube
– Mechanical complication and vibrations.
– Longer tube– Test on the recombination and transport required?
– Finned tube– Due to the azimuthal motion of the focused atomic beam
» Reduced target thickness.