News on time calibration

News on time calibration

Collaboration MeetingAmsterdam, 22-26 Nov 2010

Agustín S. LosaIFIC (CSIC – Universitat de València)

Outline

• OB system status • The new time calibration – Autobinning: Increasing chances for a good fit– Intra-Line calibration: T0s

• “Old way” vs “Automatic Calculation”• First floors calibration

– Inter-Line calibration: Time offsets• Laser OB• LED OB

• Conclusions• To-Do List

22-26 Nov 2010 Agustín S. Losa – Amsterdam Collaboration Meeting 2

Status of the OB system

• Current list of Optical Beacon not working – LED: L11F2, L11F21, L12F15 Laser: L7F0– No new dead OB, after the reconnection of lines 6 and 9– OB of L10F2 recovered

• Reminder: Optical Beacon of line 9 on floor 21 needs “EN_ACQ =0” when this Beacon is not flashing

• Special beacon for optical properties on L6F2 works: – The 6 LEDs of the TOP group emit light at 385, 400, 440, 470, 505 and 518 nm

• New RunSetups for OB runs have been created after the reconnection, still LED calibration runs no taken

• New RunSetups for OB runs will be created before HV tunning


“Old way” T0 Calculation (Reminder)

storey 2

storey 9

storey 15

storey 21

Line 1 1) Flash OMs by an optical beacon 2) Plot the distribution of hit arrival times for each ARS 3) Fit such distribution with a Gaus or Gaus @Exponential

function4) Determine Tpeak , the time of the function peak

T0 = ClockPhase + TPeak 22-26 Nov 2010 Agustín S. Losa – Amsterdam Collaboration Meeting 4

“Old way” vs “Autobinning”

So far the analysis of data to extract the T0 have been carried on “manually” in an iterative way

With the new method, refitting with different bin size of the 1800 histograms is made automatically and human inspection is replaced by a visual quick cross-check of 30 images per sector.

No

Yes

Fill histogram

Fit histogram

VisualInspection:

Success

Choose binning

Exit


No

Yes

Fill this histogram

Fit this histogram with a Gaus@Expo

Bin Size > 4 ns

Create a histogram with 0.2 ns bins

Increase histogram bin size by 0.2 ns

Choose the binning which maximizes PFit with 0.08 <

PFit < 0.95

Autobinning

NEW

Autobinning: Increasing chances for a good fit

• Fit all the time histograms with an automated method:– Fit to the convolution of a Gaussian and an exponential– Try different bin sizes (from 0.2 ns to 4 ns, in 0.2 ns steps)– Choose the fit with the best P(χ²)

• This method increases significantly the odds to have a good fit

22-26 Nov 2010 Agustín S. Losa – Amsterdam Collaboration Meeting 6not autobinned (0.2ns) autobinned (1.4ns)

Autobinning: Increasing chances for a good fit• Final fit using a colour code to help in the visual check:


PurpleOB-OM angle > 120°

Green ( Blue )OK (hits-signal / flashes > 1)

Yellow Fitted more than 50ns

CyanDifferent amplitudes >75%

Brown(hits-signal / flashes) < 0.01

RedMax statistic < 50 hits


Example of visual check for sector #3 of line 2 flashed from the L07 F15ARSARS0

ARS1

ARS2

ARS3

ARS4

ARS5

FLOOR

F11 F12 F13 F14 F15

F13 OM1

L8

L1 L2L3 L4 L6L5L7 L10L9

L11L12

The new time calibration

• Scheme of the automatic calibration:

– Human intervention only needed at the end of the process to check the output

run file & calibration

(time & alignment)

Build time OB-OM

histogramsTpeak

T0s

Time offsetsProcessing run Autobinning

Intra-Line

Inter-Line


• Early photon region– Section #1: Floors 4-10 with the OB on floor 2– Section #2: Floors 11-16 (11-17) with the OB on floor 9– Section #3: Floors 17-22 (17-23) with the OB on floor 15– Section #4: Floors 23-25 with the OB on floor 21

• Photoelectron level region (under study)– Section #0: Floors 1-3 (1-8) with an OB of other line (Laser or

LED)

Intra-Line(obtaining new T0s)

• Use the obtained T100s by autobinning to calibrate by “sections” (≠ sectors):

•


Intra-Line Example of sections #1-4 for line 1

(2 runs of 25/02/08, period of 10L)


Section #2Floor 11-16 (11-17)

Section #1Floor 4-10

Section #3Floor 17-22 (17-23)

Section #4Floor 23-25

Intra-Line“Old way” vs “Autobinning”


Comparison of both methods with the distribution of the

T0s obtained by the “Old way” minus the ones obtained by the “Autobinning” in the period 10L.

Only 24 out of 914 show a difference bigger than 1 ns.


Intra-LineCalibrating the Section #0: LEDs vs Laser

Laser OB ( L8 F0 ) LED OB ( L2 F2 )

Example of a comparison (same set of runs as before) of line 1 section #0 calibration with L2F2 LED OB and Laser Beacon on line 8

L1 L2

L3 L4 L6L5

L7 L8 L10L9

L11 L12

L1 L2

L3 L4 L6L5

L7 L8 L10L9

L11 L12

Line 1

Inter-Line(Time offsets between lines)

• For each fitted OB, Laser or LED, T100s are analyzed– Possibility to study the evolution in time along the given period– All available Laser and LED calibration runs in a given period can be used– Possibility to use the LED OB as a cross-check for the time offsets (under

study)• The whole computing time in my PC is about ~1 day per period• The short-term goal is to compute time offsets for all the periods:


5 Lines 10 Lines 12 Lines HV L10-L12+offsets HV

29/Jan/2007 07/Dec/2007 30/May/2008 13/Aug/2009 07/Nov/2009 13/Nov/2009 13/Jul/2010 Today

#1 #2 #3 #5#4 #6 #7

~10 monthsARS_T0_VERSION

10.746.202


16.703.02654.497.693

~15,5 monthsARS_T0_VERSION

16.722.42954.497.694


35.045.03655.212.410

~5 daysARS_T0_VERSION

36.934.336


37.347.048

~4,5 monthsARS_T0_VERSION

53.408.684

DurationARS_T0_VERSION

NO OFFSETSWITH OFFSETS

Line 1

Line 2

L1 L2L3 L4 L6L5L7 L8L10L9

L11L12


L11L12

Example of inter-line with Laser for the time offsets of period 10L


Line 8

Line 10


L11L12


L11L12

Example of inter-line with Laser for the time offsets of period 10L


Inter-Line“Old way” vs “Autobinning”


Line Old way Autobinning1 -2.1 -2.12 -1.9 -2.13 0.8 0.54 ---- ----5 -2.4 -2.26 -0.9 -0.97 -0.2 -0.38 7.1 7.59 1.0 0.8

10 -1.6 -1.311 ---- ----12 ---- ----

Comparison of both methods for the time offsets of period 10L, made with 12 Laser runs from 25/02/2008 to 12/05/2008


L11L12


L11L12

Line 1

Line 2

Example of inter-line with LED-OB 1025 (L9 S2)with only one run (OB 1081) (25/02/08)


Conclusions

• The new automated method for the time calibration is ready.• The method searches the best bin size to fit the hit arrival time

distributions automatically. • More than 1800 histograms fitted.• The method is fast and reduces significantly visual inspection.• Results are compatible with the “old way” method.

• No dead OB after reconnection and recovery of the L10F2• Special beacon for optical properties on L6F2 works and is

ready.


To-Do List• Intra-Line calibration:

– Apply automatic method to all the LED calibration sets– Compute new T0s after HV tuning– Study unstable PMTs– Calibrate the first floors

• Inter-Line calibration:– Obtain time offsets for all periods– Study time offsets evolution along all periods– Use LED-Beacons as a cross-check for the time offsets

• Start to use the Special beacon for optical properties on L6F2 with different wavelengths and the Nanobeacons on L9F1


Thank youfor your attention

PLEASE STAND BYBACK UP

Laser OB – Offsets 10L

Laser OB - Offsets

• One only run

Line 1

Line 2


L11L12


L11L12

22-26 Nov 2010 A. S. Losa – Amsterdam Collaboration Meeting 38

-1.0ns

-1.0ns

Line 3

Line 4

L5L1 L2L3 L4 L6L7 L8L10L9

L11L12


L11L12


-1.0ns

-1.0ns

Line 5

Line 6


L11L12


L11L12


-1.0ns

-1.0ns

Line 7

Line 8

L7 L8

L1 L2L3 L4 L6L5

L10L9L11L12


L11L12


-1.0ns

-1.0ns

Line 9

Line 10


L11L12


L11L12


-1.0ns

-1.0ns

LED OB - Offsets

• One only run

Line 1

Line 2


L11L12


L11L12


Line 3

Line 4


L11L12


L11L12


Line 5

Line 6


L11L12


L11L12


Line 7

Line 8

L8

L1 L2L3 L4 L6L5L7 L10L9

L11L12


L11L12


Line 9

Line 10


L11L12


L11L12


Use of LED OB (under study)Inter-Line with LED(only 1 run for OB)

LCM 1081 LCM 1025Line Autobinning Laser LED L9 S2

1 -2.1 -2.1 -2.8 (*)2 -2.1 -2.0 (*) -2.5 (*)3 0.5 0.3 0.94 ---- -0.8 (*) -1.8 (*)5 -2.2 -2.5 -2.86 -0.9 -1.3 -0.6 (*)7 -0.3 -0.7 2.18 7.5 7.2 (*) 6.09 0.8 0.4 5.8 (*)

10 -1.3 -1.8 0.6 (*)11 ---- ---- ----12 ---- ---- ----

22-26 Nov 2010 Agustín S. Losa – Amsterdam Collaboration Meeting 49(*) These time offsets have been obtained with low statistics

Inter-Line(Time offsets between lines)

• For each fitted OBs, Laser or LED (under study), T100s are analyzed– One set of time offsets values obtained for each OB: posibility of combine all that info for

an unique time offsets (under study)– Posibility study of evolution in time along the given period (under study) – All available Laser runs (LED calibration runs also under study) in a given period can be

used• The whole computing time in my PC is about ~1 day per period• The short term goal is to compute time offsets for all the periods without them

(blue ones):


5 Lines 10 Lines 12 Lines HV L10-L12+offsets HV

29/Jan/2007 07/Dec/2007 30/May/2008 13/Aug/2009 07/Nov/2009 13/Nov/2009 13/Jul/2010 Today

#1 #2 #3 #5#4 #6 #7

~10 mounthsARS_T0_VERSION

10.746.202


16.703.02654.497.693

~15,5 mounthsARS_T0_VERSION

16.722.42954.497.694


35.045.03655.212.410

~5 daysARS_T0_VERSION

36.934.336


37.347.048

~4,5 mounthsARS_T0_VERSION

53.408.684

DurationARS_T0_VERSION

NO OFFSETSWITH OFFSETS

2007:OFF:V2.1 2008:V2.7 2008:V2.9 2009:V3.0 2009:L12:V6.0 L8clock 2009:V3.1 2010:V3.1 ------------

Intra-Line – T0s(old)

Line 1

Section #4St (21)23-25

Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 2


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 3


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 4


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 5


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 6

Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 7


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 8


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)



Line 9


Section #4St (15)17-22(23)



Line 10


Section #2St (9)11-16(17)

Section #4St (15)17-22(23)


Calibrating Section #0 – T0s(old)


Line 1


L11L12

Laser L2 S2

L1 Section #1


Line 2


L11L12

Laser L1 S2

L2 Section #1


Line 5


L11L12

Laser L3 S2

L5 Section #1


Line 9

L9L5

L1 L2L3 L4 L6L7 L8L10

L11L12

Laser L3 S2

L9 Section #1


Summary

• Step #2: Autobinning– Because of eventual imperfect measured signal different visual checks

are provided in function of the resulting fit


Yellow → If fitted window is bigger than 50nsCyan → If difference between fitted function amplitude and signal one supere the 75%Red → If bin with most stadistic has less than 50 hitsBrown → If (hits-signal/flashes) ratio is lower than 0.01Purple → If OB-OM angle is greatter than 120°

Blue → OK, but (hits-signal/flashes) ratio is greater 1Green → OK


t[obtaining run]<t[obtaining calibration]t[obtaining calibration]~10-20min/run

t[processing]~10min/20.000events-2OB-run

t[autobin 1 line] ~??min/run

Otras cosas…

• PENDIENTE: Estudio del “desgaste” de los LED-OB debido al biofouling– PENDIENTE: Estudio del alcance de algunos LED-OB a lo largo del tiempo.

• PENDIENTE: Estudio del alcance del láser– Primer estudio: Tres runes a distintas polarizaciones tomados el mismo día comparados

con varios de intensidad normal tomados en distintos momentos– Segundo estudio: 6 nuevos runes a distintas polarizaciones tomados el mismo día

comparados con uno de intensidad normal más antiguo– Se observa una posible dependencia de la pendiente del alcance con el día:• runes del mismo día pendiente muy similar• runes de diferentes días, pendientes dispares entre sí (incluso a la misma intensidad)

– ¿Variaciones en la opacidad del agua?: Se propone un estudio en el tiempo de lo mismo– PENDIENTE: Obtención de una relación precisa “Voltaje de la Polarización” vs “Intensidad

del Láser”: pendiente de obtenerse del análisis de los datos facilitados medidos en el laboratorio a la misma frecuencia

– Se pospuso indefinidamente antes de agosto en beneficio del autobinning


Primer Estudio

Segundo Estudio

1900

1950

2000

1975

2025

2075

2125

2175

Normal

Normal

Imágenes de archivo de los estudios realizados en su día22-26 Nov 2010 Agustín S. Losa – Amsterdam Collaboration Meeting 72

Run Polarization (V) I (µJ) Alcance 1% (m)31486 1900 0,24 209,049969 1925 0,33 207,331488 1950 0,36 240,549968 1975 0,42 228,731487 2000 0,48 252,549967 2025 0,54 241,349966 2075 0,66 249,049975 2125 0,77 257,149964 2175 0,88 263,040700 Normal 1,2 274,340878 Normal 1,2 277,039418 Normal 1,2 286,038567 Normal 1,2 283,0

Valores obtenidos para el alcance delláser al nivel del 1% del photoelectrón

(1 photoelectrón cada 100 flashes)

Alcance normaldel láser al 1%:

275-285 m

AjusteIntensidad vs Alcance

(I = c + b A)

b = 70 µJ/m

c = 202 µJ

A(12 µJ) = 1040 m


L1 L2

L3 L4 L6L5

L7 L8 L10L9

L11 L12

L1 L2

L3 L4 L6L5

L7 L8 L10L9

L11 L12


L1

L2

L3

L4

L6

L5

L7

L8

L10

L12

L1

L2

L3

L4

L6

L5

L7

L8

L10

L1222-26 Nov 2010 A. S. Losa – Amsterdam Collaboration Meeting 75

St 2

St 3

St 1

St 4

St 5

St 6

St 7

St 8

St 9


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News on time calibration