PMT test setup in Erlangen

Oleg Kalekin

University of Erlangen

Pylos, 16.04.2007

Meeting

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

2

PMT Test SetupCharge response

Pulser (custom made):• Rate 10 kHz• FWHM 10ns• Variable amplitude

Dark Box:• Copper shielding• Various diameter PMT

holders

ADC LeCroy 2249A• No. of channels 12• No. of Bits 10• Full scale 256 pC

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

3

PMT Test SetupCharge response

Pulser (custom made):• Rate 10 kHz• FWHM 10ns• Variable amplitude

Dark Box:• Copper shielding• Various diameter PMT

holders• Diaphragms

ADC LeCroy 2249A• No. of channels 12• No. of Bits 10• Full scale 256 pC

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

4

PMT Test SetupCharge response

Pulser (custom made):• Rate 10 kHz• FWHM 10ns• Variable amplitude

Dark Box:• Copper shielding• Various diameter PMT

holders• Diaphragms

ADC LeCroy 2249A• No. of channels 12• No. of Bits 10• Full scale 256 pC

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

5

PMT Test SetupCharge response

Reconstruction of single-/multiple- photoelectron responseModel(*):

• 1st dynode: if mean number of ph.e., probability to detect n ph.e. = P(n, ) - Poisson function

• Anode: single ph.e. charge = G(Q1,1) – Gaussian

n ph.e. charge = G(Qn,n), Qn=n•Q1 , 2n= n•2

n

• PMT charge response: P(i,)•C(i)•exp(-(x-Qi)2/(22i)), i=1,2,…

Qi=i•Q1, 2i= i•2

1, C()=1/ 2

• 0 ph.e. (pedestal): P(0, )=exp(- ), if N – total number of event, number of pedestal events N0=N•exp(- ), and then =-ln(N0/N) can be used as first estimation of mean number of ph.e.

• Fit method: 2-minimizing with , Q1 , 1 as fit parameters

• Software: ROOT Version 5.08/00

(*) E.H. Bellamy, et al., NIM A 339 (1994) 468-476

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

6

PMT Test Setup Charge response

Reconstruction of single-/ multiple- photoelectron response: simulations

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

7

PMT Test Setup Charge response

Reconstruction of single-/ multiple- photoelectron response

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

8

PMT Test SetupAbsolute and Spectral Calibration

• Monochromator

LOT-Oriel MS301

fully automated

350-900 nm• Tungsten lamp• PMT bases for QE

measurements

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

9

PMT Test SetupAbsolute and Spectral Calibration

• Monochromator

LOT-Oriel MS301

fully automated

350-900 nm• Tungsten lamp• PMT bases for QE

measurements

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

10

PMT Test SetupAbsolute and Spectral Calibration

• Monochromator

LOT-Oriel MS301

fully automated

350-900 nm• Tungsten lamp• PMT bases for QE

measurements

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

11

Photonis PMTs

• 10" PMT ordered, expected to be delivered end of April

• 3" PMT will be provided by NIKHEF

Diam/Areainch/cm2

9/380

5/120

10/600

9/380

8/400

12/670

Euro/cm2

3.72

7.48

2.72

3.54

3.26

3.20

Oleg Kalekin University Erlangen

16.04.2007 KM3NeT Meeting, Pylos

12

Summary

• PMT test setup in Erlangen works

• Further development is in progress to cover all important PMT characteristics

• Tests of Photonis PMTs will start soon

• Hamamatsu PMTs will be evaluated to order

• Methods, codes, results will be posted on the KM3NeT Portal