<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T01:44:20Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/103243" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/103243</identifier><datestamp>2026-06-17T14:46:49Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131022</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Ulrich Becker and Andrei Kounine.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Chen, Hai, Ph. D. Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Department of Physics.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Physics</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2016-06-22T17:51:24Z</dim:field>
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   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2016</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2016</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/103243</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">951625491</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2016.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Cataloged from PDF version of thesis.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (pages 159-169).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">The cosmic ray electron and positron flux measurement can address a series of astrophysics and particle physics questions. This thesis presents an analysis of electron and positron flux from 0.5 GeV to 1 TeV using the first 30 months of data taking( over 41 billion events), with the AMS-02 detector on the International Space Station(ISS) 330-410 km above earth. A precise calibration of the Electromagnetic Calorimeter(ECAL) signals is performed to obtain stable energy measurement. A reconstruction algorithm for electromagnetic showers is implemented to measure energy and achieve high particle identification accuracy of electron and positron separating them from the proton background. The result of combined electron and positron flux measurement shows a smooth spectrum with no sharp structure. The spectral index ... above 30 GeV is observed to be ... (energy scale). This provides precise measurement for cosmic ray electrons and positrons and can contribute to probing the origin of cosmic rays, informing the studies of new physics..</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Hai Chen.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">Ph.D.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">169 pages</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Physics.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Precision measurement of electron and positron flux in cosmic rays with the AMS-02 Detector</dim:field>
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   	&lt;Title>Precision measurement of electron and positron flux in cosmic rays with the AMS-02 Detector&lt;/Title>
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   	&lt;PublicationDate>2016&lt;/PublicationDate>
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        	&lt;DisplayName>Chen, Hai, Ph. D. Massachusetts Institute of Technology&lt;/DisplayName>
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   	&lt;Abstract>The cosmic ray electron and positron flux measurement can address a series of astrophysics and particle physics questions. This thesis presents an analysis of electron and positron flux from 0.5 GeV to 1 TeV using the first 30 months of data taking( over 41 billion events), with the AMS-02 detector on the International Space Station(ISS) 330-410 km above earth. A precise calibration of the Electromagnetic Calorimeter(ECAL) signals is performed to obtain stable energy measurement. A reconstruction algorithm for electromagnetic showers is implemented to measure energy and achieve high particle identification accuracy of electron and positron separating them from the proton background. The result of combined electron and positron flux measurement shows a smooth spectrum with no sharp structure. The spectral index ... above 30 GeV is observed to be ... (energy scale). This provides precise measurement for cosmic ray electrons and positrons and can contribute to probing the origin of cosmic rays, informing the studies of new physics..&lt;/Abstract>
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