The Design of Beam Profile Monitor and the test at SRRC
description
Transcript of The Design of Beam Profile Monitor and the test at SRRC
For the FLASH Collaboration
by Taiwan CosPA Members W-Y.Pauchy Hwang, Guey-Lin Lin,
Ming-Heuy Huang, Chien-Wen Chen, Feng-Yin Chang, Chih-Ching Chen, Yu-Chung Chen,
Staff Member :Maggie Wang
The Design of Beam Profile Monitor and the test at SRRC
Chien-Wen Chen
PC2
WINDOWS XP
(LAPTOP)
CAMERA PC1
WINDOWS XP
(WORKSTATION)
SLAC
TRIGGER
SYSTEM
TUNNEL CONTROL ROOM
LAN
CAMERA CONTROL, IMAGE DOWNLOAD, DATA ANALYSE
MONITORING, REMOTE CONTROL
TRANSFER DATA OF & POSITION
TITANIUM FOIL
DESIGN OF BEAM PROFILE MONITOR
ELECTRON BEAM
HUMAN
@ @
,, yx
total 64cm
object distance 35cm
29cm
Trigger circuit
tubelens
CCD IEEE 1394
titanic foil
beam
pipe
six way
cube
beam
axis
16cm
7cm (inner)
8cm (outer)
screw holes
1.3cm
2 ft
2 ft optical
table
Cab
le tr
ay/W
all
6 inch beam pipe
e-
25 inches (wall-to-wall)~ 63.5 cm
OTR“cube”
28 inches (wall-to-beam-axis)
Top view – not to scale
Beam lineflange.
Pixels 1360x 1036
Well size 10000 e
Pixel size 4.65x
4.65
Digital output
8/12 Bit
Readout noise
9 e
Dark current 1.3/pix/s
Cooling 25C below ambient
Integration
time
Ambient operating temperature
0 to 35C
m
min 15
tos40
340
440
200
200
10
ROI
Full Frame
Spot
3x3 binning 1mm
222
2
2 )(
dddN
))33(1040(3.1(9)1065.43/()/(()()(9.09.0)(2
)(
)6
2622
abdQOdrrrfN
braNoiseSignal
ba
1
1,
OTR efficiency
transmission efficiency
quantum efficiency
pixels
readout noise
dark current
distribution# of electrons
OTR efficiency and angular distribution of a single electron for a metal foil:
The Algorithm
Integrating over one axis
200
200 200
x
i
ii
i
i
N
xxNxx
22
< x >
)2
2(
2
2
2
)(
x
xx
x
dxex
x x
center σ
10^7 95 59
10^9 9500 5870
)587(x
)950(CenterIn SLAC
30GeV
10^8 e/bunch
Maximum intensity can be analysed
:1.05x10^9 e/bunch
1mm YX
Signals per Pixel
Plotted by Feng-Yin
pixel
phot
oele
ctro
n
max σ
10^7 2550 1577
10^9 254980 157700
)15770(x
)25498(Center
1mm YX
In SLAC
30GeV
10^8 e/bunch
Signal
(Integrating over One Axis)
phot
oele
ctro
n
pixel
max σ
10^7 9 5
10^9 927 468
phot
oele
ctro
n)47(
x
pixel
Center(93)
In SLAC
30GeV
10^8 e/bunch
1mm YX
Signal to Noise Ratio per Pixel
)183(Center
center σ
10^7 18.3 11.3
10^9 1830 1130
In SLAC
30GeV
10^8 e/bunch
1mm YX
)113(x
phot
oele
ctro
n
pixel
Signal to Noise Ratio
(Integrating over One Axis)
trigger exposure readout download
the image
analyse transfer
download the
analysed data
s65 s40
360GB / 80KB = 4.5x10^6 (events)
BPM
aluminum
coating mirror
beam pipe
stainless
window
Data captured in SRRC
pixelsx 1.93
Signals =
450457 photoelectrons
σx= 1.22 mm
bunche /106.5 7
1.5 GeV
phot
oele
ctro
n
pixel
Theoretical calculation in SRRC
1.5 GeV7106.5 e/bunch
Total photoelectrons
=256389
)9727(Center
phot
oele
ctro
n (5908)x
pixel
σx= 1.22 mm
Experimental : 450457 photoelectrons
Theoretical : 256389 photoelectrons
phot
oele
ctro
n
(one metal surface)
(two metal surface)
450457 / 256389 = 1.757
Factors which may had made the difference: twice OTR, instability of the current, interference of the twice OTR.
Conclusions
1.We have captured and downloaded the image
of OTR at SRRC.
2.The S/N ratio seems to be big enough, so that
we may sacrifice some of it to increase the
MAX intensity of events which can be analysed .
3. The code to analyse and transfer data is yet to
be accomplished.