Zeuthen, January 16, 20Zeuthen, January 16, 200808

P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 11

The cosmic trigger for the The cosmic trigger for the Large PrototypeLarge Prototype

Th. Chaminade, P. Colas, K. Dehmelt, M. Karolak, G. De Lentdecker, S. Hervé, X. Janssen, Y. Kato, H. Kuroiwa, Y. Kudenko, T. Matsuda, F. Pierre, J.M.

Reymond, S. Turnbull

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 22

5 slabs on top

3 slabs at bottom

+4 perpendicular to limit the triggers to the detector length

Cosmics in March 08Beam summer 087 panels before end 09

Present layout:

12 slabs (+ 3 spare)

The Large The Large PrototypePrototype

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 33

Many possible combinations, for instance: 1 top + 1 bottom : central region of central panel3 top + 1 bottom : radial tracks on central panels3 top + 3 bottom : vertical tracks on most of the central regionRequires a ‘bridge’ to support the magnet and its movement system.

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Organization is building-upOrganization is building-up T. Matsuda (KEK) : CoordinatorT. Matsuda (KEK) : Coordinator

+ Y. Kato, H. Kuroiwa : initial tests+ Y. Kato, H. Kuroiwa : initial tests INR Moscow, Y. Kudenko : slab manufacturingINR Moscow, Y. Kudenko : slab manufacturing DESY, K. Dehmelt : on-site installation, crates, DESY, K. Dehmelt : on-site installation, crates,

trigger logictrigger logic Saclay : readout, wrapping, mechanicsSaclay : readout, wrapping, mechanics

PC (scientific coordinator), Th. Chaminade (technical PC (scientific coordinator), Th. Chaminade (technical coordinator)coordinator)

J.-M. Reymond (head of the integration lab) : cooling J.-M. Reymond (head of the integration lab) : cooling systemsystem

M. Karolak, M. Riallot, S. Hervé : mechanical design, M. Karolak, M. Riallot, S. Hervé : mechanical design, wrappingwrapping

S. Turnbull, PC, F. Pierre : testsS. Turnbull, PC, F. Pierre : tests F. Sénée (Micromegas panel technical coordinator)F. Sénée (Micromegas panel technical coordinator)

Brussels (Brussels (G. De Lentdecker, X. Janssen) TLU, logging, interfacing

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 55

The trigger has to be in a field of order 0.4 T.

MPPC : multi-pixel photo counters (so-called Silicon PM) produced by Hamamatsu

100 pixels on 1 mm2. Each is a Photodiode in Geiger mode

Operation voltage :

Vbreakdown + fraction of a Volt

Requires accurate supplies about 70 V. Need to sort the MPPCs in Vbreakdown to reduce the number of supplies.

Signal: 3 mV/p.e. (20 p.e. per fiber end, measured by Yuri Kudenko)

Dark counting rate and Vbkd sensitive to temperature : needs good temperature control: Peltier devices + thermistances+controler

1mm

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 66

SLABS (INR Moscow)SLABS (INR Moscow)New design (wrt T2K SMRD) : U-shape groove

Extrusion and machining done (width 167mm)

light output measured : 19-20 each end

Shipping to Saclay scheduled for next week

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 77

Box with photocouplers, MPPC, R,C circuit,

Thermistance, Peltier device

Wavelength shifting fiber

Scintillator slab

Controller

Trigger logic

TLU

Supply

Temperature control: Jean-Marc Reymond

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 88

Mechanics can be simple: wrapped slabs maintained by U-shape bars

Al-mylar reflector being ordered

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 99

First step : hands on MPPCFirst step : hands on MPPC

Testbox assembledTestbox assembled Amplifiers (phillips?) to be Amplifiers (phillips?) to be

decideddecided 100 V Supply selected : Voltcraft 100 V Supply selected : Voltcraft

precision PS PPS 12008 (400 € precision PS PPS 12008 (400 € each), ready to order 4.each), ready to order 4.

Thanks to many advices (J-Ch Thanks to many advices (J-Ch Vannel, Erika Garutti, Japanese)Vannel, Erika Garutti, Japanese)

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 1010

Readout and thermal Readout and thermal regulation box designregulation box design

3 parts top, bottom parallel, bottom 3 parts top, bottom parallel, bottom perpendicular.perpendicular.

In each box: thermistance, peltier In each box: thermistance, peltier devicedevice

In a central place : controlerIn a central place : controler Design mechanics, system, cablesDesign mechanics, system, cables Light-tightness vs accessibilityLight-tightness vs accessibility Visit to DESY with Klaus Dehmelt before Visit to DESY with Klaus Dehmelt before

mid-Februarymid-February

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 1111

Conclusion and plansConclusion and plans Need a robust system: temperature Need a robust system: temperature

controlcontrol Slabs delivered next week (tbc)Slabs delivered next week (tbc) Wrapping in Saclay 2 weeks afterWrapping in Saclay 2 weeks after Installation in MarchInstallation in March Connexion to DAQ in MarchConnexion to DAQ in March

Zeuthen, January 16, 2008Zeuthen, January 16, 2008 P. Colas - LP cosmic triggerP. Colas - LP cosmic trigger 1212

The gain depends on Vbias, and Vbreakdown depends on the temperature

Requires both a stable and precise supply and a controlled temperature.

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