Inserire curva di attenuation length normale

Warning do not trust the error

Warning Preliminary results

0.8 mm 250 ppm part 1 - measure 2

Fit from 0 to 17 m

3 August 2006

Preliminary

1 = 7620 +/- 400 mm

2 = 3580 +/- 1000 mm

The first measurement on this fiber, made on half the points only :

Fit from 0 to 17 m

0.8 mm 250 ppm part 1 - measure # 2

18 August 2006

why to fit from 0 till 17 m only ?

1 2( )x x

f x A e e

The data were fitted to the functional form:

Fit from 0 to 9 m

Fit from 9 to 24 m

0.7 mm 150 ppm part 1 - measure 01 0.7 mm 150 ppm part 1 - measure

01

9 August 2006

18 August 2006

    1 ( m )  

  0.6 0.7 0.8

150   8.79 ± 0.10 ± ??? 8.61 ± 0.08 ± ???

200      

250     8.44 ± 0.06 ± ???

300   8.46 ± 0.11 ± ???  

    2 (m )  

  0.6 0.7 0.8

150   3.54 ± 0.14 ± ??? 3.19 ± 0.14 ± ???

200      

250     2.58 ± 0.1+/-???

300   2.66 ± 0.06 ±???  

Preliminary results18 August 2006

Riproducibility on 1 meter of fiber measurement Riproducibility on 1 meter of fiber measurement

18 August 2006

3.13

3.44

3.28

3.19

3.26 Avg

0.13 std dev

0,13 / 3,26 = 4,0%

• Study the systematics • Estimate the measurement reproducibility

To be further investigated:

Systematic in the measurement

• increase of the length of the motorized bench to 1.5 m

Upgrade of the apparatus:

• more focussed and better shielded led spot

9000

9500

10000

10500

11000

11500

12000

12500

13000

13500

14000

0.00 0.20 0.40 0.60 0.80 1.00

Series1

Series2

Series3

Series4

N. Moggi , S. Zucchelli and A. Barbieri ISOF- CNR Bologna

Measurements performed at ISOF CNR-Bologna on a 25 meter 0.8 mm 200 ppm ( reference) fiber.

Spectral response as function of distance along the fiber

18 August 2006

The light source was a Helium-Cadmium Kimmon S3522 laser 442 nm continous emission laser, 37 mW, beam spot diameter ~0.94 mm, laser stability ~ +/- 2%.The fiber was coupled to an Avantes - AVA Spec 2048 spectrometer.

Baseline subtracted and corrected Spectrum as function of distance for reference fiber ( 0.8 mm 200 ppm)

0

20000

40000

60000

80000

100000

120000

350

364

377

391

404

418

431

445

458

472

485

499

512

526

539

553

566

580

593

607

620

634

647

661

674

688

Wave length

Co

un

ts/s

ec

0.5 m corrected data

5 m corrected data

10 m corrected data

15 m corrected data

20 m corrected data

25 m corrected data

1 m corrected data

2 m Corrected data

Baseline subtracted Spectrum at 0.5 meters of reference fiber ( 0.8 mm 200 ppm)

-10

19990

39990

59990

79990

99990

119990

0.00

29

0.00

27

0.00

26

0.00

25

0.00

24

0.00

24

0.00

23

0.00

22

0.00

21

0.00

21

0.00

20

0.00

19

0.00

19

0.00

18

0.00

18

0.00

17

0.00

17

0.00

17

0.00

16

0.00

16

0.00

15

0.00

15

0.00

15

0.00

14

Wave length

Co

un

ts/s

ec

Corrected Data

0

5

10

15

20

25

30

35

40

45

50

220

313

406

499

592

685

778

871

Series1

Series2

Baseline subtracted and corrected Spectrum as function of distance for reference fiber ( 0.8 mm 200 ppm)

1

10

100

1000

10000

100000

350

363

375

388

400

413

425

438

450

463

475

488

500

513

525

538

550

563

575

588

600

613

625

638

650

663

675

688

700

Wave length

Co

un

ts/s

ec

0.5 m corrected data

5 m corrected data

10 m corrected data

15 m corrected data

20 m corrected data

25 m corrected data

1 m corrected data

2 m Corrected data

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

480

490

500

510

520

530

540

550

560

570

580

590

600

610

620

630

640

650

660

670

680

690

700

Series1

18 August 2006

Fit to a single exponential: inverse of attenuation length as function of wavelenght

AREA NORMALIZED Spectrum as function of distance for reference fiber ( 0.8 mm 200 ppm)

0

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.01

350

364

377

391

404

418

431

445

458

472

485

499

512

526

539

553

566

580

593

607

620

634

647

661

674

688

Wave length

Co

un

ts/s

ec

0.5 m Normalized data

5 m normalize data

10 m Normalized data

15 m Normalized Data

20 m Normalized Data

25 m Normalized Data

1 m Normalized Data

Plan for the immediate future:

Next:

Pseudocumene from Borexino shall arrive in Bologna by end of August.• Start test of fiber survival in pseudocumene • Start aging test

• Complete on all the fibers the measurements of attenuation length. 0.6 mm fiber is next. 0.6 150 ppm should be under way right now . • Measure relative light yeald • Measure spectral response.• Test of fiber response as function of bending radius

Results foreseen for next Nova Collaboration meeting in November 06

18 August 2006