Status of NEWCHOD E Guschin INR S Kholodenko

Status of NEWCHOD E. Guschin (INR), S. Kholodenko (IHEP), Yu. Kudenko (INR), I. Mannelli (Pisa), O. Mineev (INR), V. Obraztsov (IHEP), V. Semenov(IHEP), V. Sugonyaev (IHEP), R. Wanke (Mainz)… NA 62 meeting, Ferrara, 3 Sept 2014

NEWCHOD geometry 144 individual tiles WLS + Si. PM readout

Prototype scintillator counters Prototype: 18 scintillator counters Dimensions: 5 counters 30 mm (thickness) x 108 mm (width) x 268 mm (length) 9 counters 30 mm (thickness) x 108 mm (width) x 134 mm (length) +4 of special dimensions (around the beam + corner) Readout: 16 Bicron WLS fibers 1 mm for big counters, 8 for small Photosensors: two pairs of 3 x 3 mm 2 Sens. L Si. PM per one big counter, two Si. PM's per small counter

Scintillator counters Two rows will be mounted on one side of the Master plate, one row on the other

Sens. L Micro. FC-30035 -SMT o SPECIFICATION from datasheet (at 21 C): Sensitive area size : Number of pixels : Pixel size : 3 x 3 mm 2 4774 35 x 35 µm 2 Gain : 3 x 106 Operating voltage: VBR+2. 5 V Dark count rate: 300 k. Hz (typ. ) Crosstalk: 7% (typ. ) Peak spectral sensitivity: 420 nm PDE at 520 nm: ~20% Back side Tested samples are in surface mounted package Overvoltage range: 1 - 5 V Typical overvoltage: 2. 5 V Front side

Sens. L Si. PM 3 x 3 mm 2 Si. PMs

Sens. L signal from LED individual p. e. peaks are well separated

Crosstalk and dark rate Dark rate and level of crosstalk in Si. PM are evaluated using a dark spectrum of a photosensor. Poisson distribution ratios allow us to calculate the parameters.

Photon detection efficiency PDE at 520 nm with subtracted crosstalk component. Error is determined mainly by calibration accuracy. i rel P ary min

Front-end Electronics (1) 16 channel Amplifier boards: Output 4 -6 m. V for 1 p. e. Power consumption 40 m. W/channel Master board, which houses 8 Si. PM boards and 1 Amplifier board Si. PM board with pins, which position Black Head with 4*4 fibers; Guard plate, which prevents fibers from touching Si. PM's Si. PM boards (8 per Master board), house 2 Pairs of Si. PM's

Front-end Electronics (2)

Status 18 counters are manufactured (with grooves), Tyvek envelopes in preparation. 64 Sens. L Si. PM are bought and tested. 64 amplifier channels are manufactured and tested. Production of 4 mother boards, 32 Si. PM boards, 32 Black heads in progress. 1 mm Bicron fibers are already at CERN.

Plan Mechanics at CERN ? ? Counters at CERN middle of September Electronics at CERN middle of October Assembly of mechanics, fibers preparation and gluing September-October Counters mounting September-October Transportation, Installation ? ? Tests during NA 62 run November