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.