ABSORPTION LENGTH STATUS

(group meeting)

HAROLD YEPES RAMIREZ

IFIC, December 17th 2009

DATA TAKING

• There are not new optical properties runs available mean rates over the detector ~150 kHz.

DATA ANALYSIS

• First draft of absorption length paper for Nuclear Instruments and Methods Journal (from VLVnT09 proceedings) is ready for comments and corrections, deadline January 15th, to upload it into web page.

• Checking the LEDs model for L12F2 beacon (KM3NeT prototype):

UV (Cleaved) 950 nJ

CB 30 200 nJ

CB 15 (Cleaved-ANTARES) 50 nJ

LED ID [nm] Power [nW] – Energy (nJ)

UV (Cleaved) 400 (uv) 950 nJ

UV (Cleaved) 400 (uv) 950 nJ

CB 30 470 (blue) 13 nW – 200 nJ

AB 87 470 (blue) 30 nW

NSPB 500S 470 (blue) 97 nW

CB 26 470 (blue) 32 nW

Procedure:

1. Compute the velocity of light for all LEDs ID Low statistics No phe level analysis 1/v as reference parameter:

¿Why do we have lack of statistics for UV runs?

Run (beacon face) 1/v [ns/m]

45159 (1) 4.74 (uv)

45160 (2) 4.74 (uv)

45161 (3) 4.67 (blue)

45162 (4) 4.67 (blue)

45163 (5) 4.67 (blue)

45164 (6) 4.67 (blue)

Procedure:

2. Take a look over charge distributions:

3. Summary blue LEDs classified by energy:

Run Charge integral (F6) Charge integral (F9)

45159 7.07*10^4 (uv) 2.1*10^4 (uv)

45160   9.31*10^4 (uv) 2.7*10^4 (uv)

45161 1.13*10^5 (blue) 8.37*10^4 (blue)

45162 9.26*10^4 (blue) 5.46*10^4 (blue)

45163 1.05*10^5 (blue) 9.51*10^4 (blue)

45164 1.00*10^5 (blue) 9.52*10^4 (blue)

beacon face LED ID

1 UV (cleaved)

2 UV (cleaved)

3 NSPB 500S

4 CB 30

5 AB 87

6 CB 26

DATA ANALYSIS

• Charge -Time distributions for signal hits OM by OM photoelectron region is considered:

PHOTOELECTRON REGION RUN: 33983

[90, 220] ≡ [F9, F17]

DEAD CHANNEL DEAD CHANNEL

DATA ANALYSIS

• Charge -Time distributions for signal hits OM by OM photoelectron region is considered:

PHOTOELECTRON REGION RUN: 36035

[60, 220] ≡ [F7, F17]

Low efficiency OM (low efficiency cleaning)

Low efficiency OM (low efficiency cleaning)

• To other golden runs we have similar distributions where we can see the hits and charge losses:

http://ific.uv.es/~yepes/optical_properties/distributions/

• Do we need to consider a new cleaning based on the charge losses for the OMs?

A new preliminary visual inspection is required?

DATA ANALYSIS

• The summary of the last group meeting Tmax influence over values for L parameter (10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 1000) ~ Inputs MC (18 runs)

• Real data: each point corresponds to the mean value of the distribution of 18 runs in each time window.

Monte CarloReal data

TO CHECK…