ECAL Testbeam Meeting, Rome 28 March 2007 Toyoko Orimoto Adolf Bornheim, Chris Rogan, Yong Yang California Institute of Technology Lastest Results from

ECAL Testbeam Meeting, Rome28 March 200728 March 2007

Toyoko OrimotoToyoko OrimotoAdolf Bornheim, Chris Rogan, Yong YangAdolf Bornheim, Chris Rogan, Yong Yang

California Institute of TechnologyCalifornia Institute of Technology

Lastest Results from Laser Monitoring Irradiation Studies at H4 2006

28 March 2007 T. Orimoto - Irradiation Studies at H4 2

Outline

Overview of Irradiation Runs at H4

Transparency correction studies

Dividing single crystal into 5x5

Possibility of looking at irradiated neighbors

Summary


Irradiation runs at H4 2006

Period Comments Xtal HoursEnerg

yRate

(S6, S2)

Sept Normal SPS cycle length 168 ~12 120 12k, 6k

Nov:

04.-06.11.

Limited maximum rate available due to SPS problems and H2 priority, 40s SPS cycle.

Nicolo suggested running at 90 GeV which yields highest rates at H4.

Global timing offset by 1 clock cycle only 2 samples after the maximum. Corrected for the laser after 35 hours of running.

148 ~15 90 12k, 6k

552 ~12 90 12k, 6k

672 ~6 90 30k, 13k

128 ~10 90 30k, 13k

Nov: 12.11

High rates available, 40 s SPS cycle

Additional timing problems (SPS clock synchronization lost).

88 ~12 90 60k,


Irradiation SM22 XTAL168

Irradiation at the end of the (second) beam period for SM22.

Rate : ~12k on S6 ~6k on S2 @ 120 GeV

Significant drop in APD/PN for 168. Some drop in 167, all other neighbors no obvious change.

Note : Correlated fluctuations in neighboring channels


November Irradiation SM06 Xtal 148

Maximum dose rate limited because of SPS problems and priority to H2 for 0 running.

Irradiation of xtal 148 with ~12k on S6, ~6k on S2 @ 90 GeV (rate maximum for H4)

Very small change on xtal 148 (~0.25%) under direct irradiation.

Neighboring xtals show up to ~1%. Note : Xtals 16* are also in the area of linearity scan.

AP

D/A

PD

_re

f

Linearity scan ?



Irradiation of xtal 552 with ~12k on S6, ~6k on S2 @ 90 GeV

Xtal 552 shows even less change (~0.6%), and all its neighbors even less.

Note : Choice of reference APD not optimal More noise.

AP

D/A

PD

_re

f



Irradiation of xtal 672 with ~30k on S6, ~13k on S2 @ 90 GeV (improved SPS performance)

Xtal 672 shows even less change (~0.1%), two neighbors show significantly more.All other neighbors show no change Note : Choice of reference APD optimal Very little noise.

AP

D/A

PD

_re

f


November Irradiation SM06 Xtals 128 & 88

Irradiation of xtal 128 with ~30k on S6, ~13k on S2 @ 90 GeV

Noticed ‘softness’ of xtal 128 in initial irradiation of xtal148 Irradiate it.

Noticed ‘softness’ of xtal 108 Next irradiation should be 88.

AP

D/A

PD

_re

f


Irradiation - Xtal 168

Hodoscope hits - entire irradiation period of ~12 hours

Beam events distributed throughout

crystal

Sufficient statistics to explore variations in

electron response within crystal

C. Rogan



Hodoscope hits - entire irradiation period

Reconstruct electron data for 25

different bins

Generate R-plot for each bin

C. Rogan



Example energy distribution for R-plot point (central bin)

Each point in R-plot is derived from an energy

distribution corresponding to a continuous time interval

Peak is fit and value is extracted (and error)

Bins further from center suffer from less statistics in

given time interval

More difficult to resolve electron response

Bin centered at -8, -4 (mm)

~ .89%

~ 1.1%

C. Rogan



For each time interval an interpolated laser response is

calculated

R computed with normalized laser and electron responses

C. Rogan


Irradiation - Xtal 168C. Rogan


Irradiation - Xtal 168 (5x5)C. Rogan

-0.30 ± 0.05

1.47 ± 0.02

1.53 ± 0.03

0.93 ± 0.03

1.26 ± 0.05

1.38 ± 0.02

1.64 ± 0.01

1.48 ± 0.01

1.490± 0.01

1.29 ± 0.02

1.53 ± 0.01

1.38 ± 0.01

1.37 ± 0.01

1.47 ± 0.01

1.18 ± 0.02

1.37 ± 0.01

1.40 ± 0.01

1.39 ± 0.01

1.46 ± 0.01

1.36 ± 0.02

1.44 ± 0.03

1.38 ± 0.02

1.41 ± 0.02

1.17 ± 0.02

1.17 ± 0.05

Mean = 1.373

RMS = 0.1468

Central bin

fit for R



Alpha values used to correct electron response

Uncorrected E9 Corrected E9 ~ 1.2% ~ .53%

No intercalibration constants used

Surrounding crystals uncorrected

C. Rogan



6.28 ± 0.23

4.71 ± 0.16

-1.21 ± 0.10

-0.35 ± 0.12

1.63 ± 0.17

1.91 ± 0.08

1.92 ± 0.06

1.73 ± 0.05

1.42 ± 0.05

4.42 ± 0.15

1.74 ± 0.05

1.91 ± 0.04

1.55 ± 0.03

1.43 ± 0.04

1.49 ± 0.01

1.71 ± 0.05

1.61 ± 0.03

1.59 ± 0.03

1.96 ± 0.04

0.38 ± 0.07

1.77 ± 0.07

1.73 ± 0.06

2.54 ± 0.06

2.01 ± 0.06

1.20 ± 0.11

Mean = 1.73

RMS = 0.28

Central bin

fit for R



130.6 ± 33.1

42.4 ± 19.6

-7.4 ± 1.7

14.4 ± 6.0

26.1 ± 6.5

9.8 ± 1.3

1.9 ± 0.3

6.3 ± 0.8

39.8 ± 17.4

18.4 ± 7.0

4.1 ± 0.5

2.8 ± 0.3

4.2 ± 0.4

6.2 ± 0.7

13.0 ± 1.6

4.1 ± 0.5

4.1 ± 0.5

3.2 ± 0.3

3.9 ± 0.4

14.7 ± 1.7

5.8 ± 0.8

6.5 ± 0.8

2.5 ± 0.4

4.7 ± 0.6

102.7 ± 26.6

Mean = 4.671

RMS = 1.933

Central bin

fit for R


QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.


Mean = 1.431

RMS = 0.437

Central bin

fit for R9.59 ± 0.41

1.09 ± 0.14

1.85 ± -0.15

-1.22 ± 0.18

1.71 ± 0.24

2.36 ± 0.12

1.12 ± 0.06

1.02± 0.06

1.82 ± 0.08

4.55 ± 0.21

0.68 ± 0.08

1.76 ± 0.05

1.50 ± 0.04

1.41 ± 0.05

3.54 ± 0.15

1.39 ± 0.08

1.47 ± 0.04

1.48 ± 0.05

1.55 ± 0.06

3.29 ± 0.15

0.40 ± 0.14

1.20 ± 0.09

1.59 ± 0.09

1.80 ± 0.10

6.22 ± 0.29


QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.


28.4 ± 8.4

23.1 ± 6.2

6.8 ± 1.8

26.2 ± 8.8

24.6 ± 8.0

6.3 ± 1.3

4.3 ± 0.8

3.1 ± 0.8

5.0 ± 0.9

14.4 ± 3.4

- ± -4.0 ± 0.7

2.9 ± 0.5

2.4 ± 0.5

24.5 ± 6.8

5.4 ± 1.2

2.2 ± 0.4

4.2 ± 0.7

4.3 ± 0.8

4.6 ± 1.2

-10.4 ± 2.8

4.6 ± 0.9

4.4 ± 1.0

11.8 ± 2.9

36.0 ± 8.9

Mean = 4.295

RMS = 1.274

Central bin

fit for R


Irradiation - neighboring crystals

Studying possibility of extracting R-values from

neighboring crystals using hits in those crystals…

However, much lower statistics

Example hodoscope profile for run (Xtal 128)

Possible by examining shower response in

neighbors from central xtal hits?

C. Rogan


Conclusion

6 crystals have been irradiated for extended periods at H4 TB in 2006, most with limited rate.

3 out of 6 crystals (168, 128, 552) showed clear transparency change. 2 showed little and one almost no change. (148, 672)

Several neighbor crystals showed clear transparency change. We are studying how to extract R values from that.

Transparency corrections and performance after transparency corrections are under study.

Begin estimating the systematic uncertainties of the transparency correction.

Some limited studies on other aspects of the crystals can be studies, eg. recovery times, radiation hardness, etc.

We strongly recommend more irradiation studies, perhaps during testbeam for endcaps


Back up Slides


Irradiation Runs at H4

September Irradiation : Xtal 168 of SM22: ~12 hours, rates ~12k on S6, ~6k on S2 @ 120 GeV, normal

SPS cycle length

November Irradiation : Many issues due to problems with timing

04.-06.11. :

Limited maximum rate available due to SPS problems and H2 priority, 40s SPS cycle.

Nicolo suggested running at 90 GeV which yields highest rates at H4.

Global timing offset by 1 clock cycle only 2 samples after the maximum.

Corrected for the laser after 35 hours of running. Xtal 148 on SM06 : ~15 hours, ~12k on S6, ~6k on S2 Xtal 552 on SM06 : ~12 hours, ~12k on S6, ~6k on S2, beam unstable Xtal 672 on SM06 : ~6 hours, ~30k on S6, ~13k on S2 Xtal 128 on SM06 : ~10 hours, ~30k on S6, ~13k on S2

12.11. :

High rates available, 40s SPS cycle, 90 GeV , additional timing problems in H4 (SPS clock synchronization lost). Xtal 88 on SM06 : ~12 hours, ~60k on S6

Next slides : Lots of Scatter plots !


APD/APD_ref vs APD/PN

Effect is small on the first period of the November data, larger later after clock synchronisation loss.

During long term follow up there might also be other incidents (eg. cooling interlock at ~3925 hours).

APD/APD_ref

APD/PNA

PD

/AP

D_r

efA

PD

/PN


November Irradiation

More soft neighbors in the area of xtals 148, 128 and 88.

Note : Odd behavior of xtal 87 before irradiation.

AP

D/A

PD

_re

f

AP

D/A

PD

_re

f

Xtal 87


Transparency Change Correction – Xtal 168

Correction R computed using 1x1 electron response


Resolution after correction: SM22 168

SM Crystal R Res before Res after

22 168 1.41 ± 0.01 0.93% 0.53%






06 552 1.54 ± 0.05 0.82% 0.77%






06 672 0.99 ± 0.08 0.69% 0.67%






06 128 1.82 ± 0.04 0.83% 0.68%


R values from 5x5 of 168 and 128

168

Mean = 1.373

RMS = 0.1468

128

Mean = 1.73

RMS = 0.2806


Irradiation - Xtal 168 (center)

Rel

ativ

e el

ectr

on

res

po

nse

Relative Laser Response

C. Rogan



-0.30 ± 0.05

1.47 ± 0.02

1.53 ± 0.03

0.93 ± 0.03

1.26 ± 0.05

1.38 ± 0.02

1.64 ± 0.01

1.48 ± 0.01

1.490± 0.01

1.29 ± 0.02

1.53 ± 0.01

1.38 ± 0.01

1.37 ± 0.01

1.47 ± 0.01

1.18 ± 0.02

1.37 ± 0.01

1.40 ± 0.01

1.39 ± 0.01

1.46 ± 0.01

1.36 ± 0.02

1.44 ± 0.03

1.38 ± 0.02

1.41 ± 0.02

1.17 ± 0.02

1.17 ± 0.05

Mean = 1.373

RMS = 0.1468



Alpha values used to correct electron response

Corrected E9 ~ .67%

No intercalibration constants used

Surrounding crystals uncorrected

Uncorrected E9 ~ .82%

C. Rogan



6.28 ± 0.23

4.71 ± 0.16

-1.21 ± 0.10

-0.35 ± 0.12

1.63 ± 0.17

1.91 ± 0.08

1.92 ± 0.06

1.73 ± 0.05

1.42 ± 0.05

4.42 ± 0.15

1.74 ± 0.05

1.91 ± 0.04

1.55 ± 0.03

1.43 ± 0.04

1.49 ± 0.01

1.71 ± 0.05

1.61 ± 0.03

1.59 ± 0.03

1.96 ± 0.04

0.38 ± 0.07

1.77 ± 0.07

1.73 ± 0.06

2.54 ± 0.06

2.01 ± 0.06

1.20 ± 0.11

Mean = 1.73

RMS = 0.28


Irradiation - Xtal 128 (center)

Relative Laser Response

C. Rogan

Rel

ativ

e el

ectr

on

res

po

nse


signal from Laser signal from Laser

sig

nal

fro

m B

eam

(e

sig

nal

fro

m B

eam

(e-- ) )

a

a

slope : = 1.55

Dispersion of Dispersion of for 28 BTCP crystals for 28 BTCP crystals

Coefficient for crystals have relatively small dispersion.Coefficient for crystals have relatively small dispersion.

mean mean 5%5%

on a ~5% correction due on a ~5% correction due to the effect of irradiationto the effect of irradiation

mean mean 5%5%

on a ~5% correction due on a ~5% correction due to the effect of irradiationto the effect of irradiation

At startup use same parameters for all crystals from one producer.

An in-situ determination of is under consideration.

2002

2003

2004

2004

(fall)

(spring)

# C

ryst

als

Laser Light Loss – Electron Signal Loss

Documents

ECAL Testbeam Meeting, Rome 28 March 2007 Toyoko Orimoto Adolf Bornheim, Chris Rogan, Yong Yang California Institute of Technology Lastest Results from