Charge resolution of the ISS-CREAM SCD measured with a heavy-ion - - PowerPoint PPT Presentation

Charge resolution of the ISS-CREAM SCD measured with a heavy-ion beam

G.H. Hong, SungKyunKwan Univ. On behalf of the SCD group of ISS-CREAM collaboration.

Contents

• Introduction
• Instrument for the heavy-ion beam test
• Trigger detector
• SCD prototype electronics
• Data analysis
• Result
• Summary

• The Cosmic Ray Energetics and Mass experiment

at the International Space Station (ISS-CREAM) is designed to measure the energy and composition

• f energetic cosmic rays at the International Space

Station.

• ISS-CREAM payload will be launched and installed

at the ISS in August 2017.

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Introduction The Cosmic Ray Energetics And Mass experiment at the International Space Station

Silicon charge detector (SCD) In ISS-CREAM Payload

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Introduction

Balloon-borne CREAM (2004~2016): Double-layer SCD

BSD Instrument BCD Instrument TCD Instrument Calorimeter Targets

SCD

Not Shown (Located behind Power Dist ribution Boxes

• Housekeeping Box
• Science Flight Computers

ISS-CREAM: Quadruple-layer SCD

People who contributed to this work

SCD group: I.H. Park, J. Lee, H.Y. Lee, J.A. Jeon, S. Jeong, G.H. Choi, G.H. Hong. Crew for heavy-ion Beam test at CERN:

• S. Jeong, S. Nutter, G.H. Hong, G.H. Choi,
• G. Gaikove, M.B. Kim, H.M. Jeong.

Beam Trigger detector SCD prototype 4 layer

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Instrument

▪ Beam line : North area H4 and H8 at CERN ▪ Beam status: Primary lead ion, fragmented down.

• Momentum of heavy-ion : 60.2 GeV/c per nucleon.
• A/Z = 2.0

▪ Beam size RMS ~ 1cm

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Instrument

SCD prototype

4-layer configuration of silicon sensor with 128 pixels and readout electronics which were of the same types as the ones installed in the ISS-CREAM SCD.

(A) (B) (D) (C)

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Data analysis

Data selection and analysis

1st layer and another layer

• Convert the energy loss measurement(dE/dx) to the charge(Z).
• The double-layer charge distribution was obtained by selecting the central band
• f the 2- dimensional plot and taking the average of Z1 and Z2.
• The triple-layer and quadruple-layer charge measurements were obtained by

selecting such central bands in correlation.

Charge distribution of the ions

Charge resolution(in charge unit)

1 layer 2 layer 4 layer

C 0.213 0.177 0.117 Fe 0.222 0.160 0.118

average 0.270 0.178 0.137

Fe He

C O Si B Li Be N F Ne Na Ma Al P S

Charge resolution

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Result (Preliminary)

0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 5 10 15 20 25 30 1 layer 2 layers 4 layers

• The charge resolution improves as the number of

layers increases.

• The charge resolution measured with four layers

shows twice batter then single layer result.

Charge resolution of the ions from He to Zn Charge distribution of the ions

5 10 15 20 25 30 5 10 15 20 25 30

Mean_Z Z

Charge Peaks

Slightly non-linear

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Result

• We have been trying to figure out where this

non-linearity comes from.

• No non-linearity was found in a stand-alone

test of ADC on the digital board.

• We suspect that this non-linearity originates

from the preamplifier on the analog electronics board.

• Once the origin of the non-linearity is found,

we can correct it.

Linearity in response

▪ ISS-CREAM SCD can measure cosmic rays up to z = 30. ▪ The instrument requirement of the SCD on charge resolution is met (𝜀𝑎 = 0.137 e < 0.2 e) ▪ Non-linearity : the stand-alone test of preamplifier will follow to find its origin.

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Summary