The DAMPE space mission:
status and main results
Francesca Alemanno*(on behalf of the DAMPE collaboration)*email: francesca.alemanno@gssi.it

The DAMPE space mission
The DArk Matter Particle Explorer (DAMPE) is a satellite-based experiment
The DAMPE collaboration involves several institutes in China and Europe

DAMPE was successfully launched in a Sunsynchronous orbit on December 17th 2015
from the Jiuquan Satellite Launch Center●●ALTITUDE: 500
500 kmkm
ALTITUDE:➔
INCLINATION: 97°97°➔INCLINATION:➔PERIOD: 95
95 minutesminutes➔
PERIOD:➔
ORBIT: Sun-synchronous
Sun-synchronous➔ORBIT:➔➔

20th Lomonosov conference, 19-25/08/2021●●●●●CHINA
ITALY●Purple Mountain Observatory, CAS, Nanjing
INFN Perugia and University of Perugia
University of Science and Technology of China, Hefei ● INFN LNGS andInstitute of High Energy Physics, CAS, Beijing
Gran Sasso Science Institute●
University of Chinese Academy of Sciences, Beijing
INFN Bari and University of Bari
●National Space Science Center, CAS, Beijing
INFN Lecce and University of Salento
Institute of Modern Physics, CAS, Lanzhou
SWITZERLAND●
University of Hong Kong, Hong Kong
University of Geneva

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

2DAMPE scientific objectives
Galactic COSMIC RAYS

e+ - e- spectrum
Expectedperformance

IO NTAULM
IS

γ-ray astronomy

ION
TA
UL
M
IS

DARK MATTER searches

Multimessenger
astronomy

Exoticparticles
20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

3

The DAMPE experiment
Mass:
Mass: 1400
1400kgkg
Power:
Power: ~~400400W
W
Livetime:
Livetime: >> 33 years
yearsEnergy
Energy range:range:
55GeV
GeV–– 1010TeV
TeVe/γe/γ5050GeV
GeV–– 200200TeV
TeVprotons
protonsandand nucleinuclei

20th Lomonosov conference, 19-25/08/2021

DAMPE

AMS-02Fermi LATe/γ energy res.@100 GeV (%)

1.2

310e/γ angular res.@100 GeV (deg)

0.2

0.3

0.1

e/p discrimination

105-106

105-106

103

Calorimeter thickness (X0)

32

17

8.6

Geometrical accep. (m2sr)

0.3

0.091

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

4Detector structure
Plastic Scintillator Detector (PSD)

Silicon-Tungsten tracKer (STK)

Charge measurement +identification of electrons andgamma-rays

Silicon strips (precise tracking) +tungsten converter (pair production)

BGO Calorimeter (BGO)

NeUtron Detector (NUD)

J. Chang et al., Astrop. Phys. 95(2017)6-24

Energy measurement + e/p
separation
ICRC 2021, 12-23/07/2021

Additional hadrons rejection

Francesca Alemanno on behalf of the DAMPE collaboration
Measurement of the light component (p+He) energy spectrum with the DAMPE space mission5Particle selection and identificationProtonElectronGamma

PSD
STK

BGO
NUD

20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

6Gamma-ray lines

Many DARK MATTER candidates …
WIMP hypothesis

ICRC 2
gamma-ra 021 – XU Zun-Lei, Se
y lines in thae Galaxy wrch for
ith DAMPE
5 years of data:
ststJanuary 1 2016 – December 31 2020
Energy range: [5 – 450] GeV

If two WIMPs (χ) can annihilate
into a photon (γ)
and another particle (X),
we should see a~ monochromatic structure at
Eγ = mχ (1-m2X/4m2χ)
DAMPE energy resolution for photons < 1%
20th Lomonosov conference, 19-25/08/2021

Average Spectral
Energy Distribution (SED)

Search for signals in different ROIs
SED almost featureless andno obvious line-likestructure can be foundNo line signals or candidates with TS ≥ 9with 5 years of DAMPE data

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

7Gamma-ray lines

95% confidence level constraints
on the annihilation cross section
or decay lifetime withsystematic uncertainties included

DAMPE 5-year results comparable with
5.8-year results of Fermi-LAT

20th Lomonosov conference, 19-25/08/2021

ICRC 2
gamma-ra 021 – XU Zun-Lei, Se
y lines in thae Galaxy wrch for
ith DAMPE

For the decaying DM, DAMPE lower
limits on the decay lifetime are stronger
for DM with mass ≤ 100 GeV

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

8Gamma-ray sky
5-years gamma-ray data

ICRC 2021– Du
gamma-ra an Kai-Kai, Observati
y sources woith DAMPE n of

Globular Cluster

120 M seconds livetime andmore than 220’000 photons above 2 GeV
20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

9Electron IDentification
Comparison of flight data andMC simulations of the ζ distributions

Discrimination between electronsand protons in the BGO

Protons
500 GeV < Edep < 1 TeVElectr
ons
500 GeV < Edep < 1 TeV

Electrons

Ratio of energy deposited in the last BGO layer
to the total energy deposited in the BGO calorimeterSum of the energy-weighted
shower dispersion of each layer

20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

10All-electron spectrum
Measurement of the spectrum in the energy range
25 GeV – 4.6 TeV~ 530 days of data (27 Dec 2015 – 8 Jun 2017)
Proton contamination < 3% @ [50 GeV – 1 TeV]EVIDENCE OF
A BREAK AT ~ 0.9 TeV

20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

11

Identification of nuclei

PSD
Bethe-Bloch formula:dE/dx α Z2Nuclei

ChargeResolution

p0.13

He0.12

Li0.14

Be0.21

B

0.17

C0.18

N0.21

O

0.21

Fe0.32

Charge measurement also given
by STK and (with lowerprecision) by BGO bars

ICRC 2021 – Chuan Yue, Measurement ofthe Boron to Carbon Flux Ratio in Cosmic
Rays with the DAMPE Experiment
20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

12Proton spectrum20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

13

Proton spectrum●●

20th Lomonosov conference, 19-25/08/2021

Confirmation of a hardening structure
at ~500 GeV
Detection of a softening at ~14 TeV
with high significanceFrancesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

14Helium spectrum

20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results15Helium spectrum●●

20th Lomonosov conference, 19-25/08/2021

First detection of asoftening at ~34 TeV
Suggesting of acharge dependent feature

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

16p+He spectrum

ICRC 202
Measurem 1 – Francesca Alema(p+He) ene ent of the light com nno,
rgy spectru
pm with the onent
DAMPE
space mission

Good agreement with the sum of thetwo proton and helium independent analysis!
20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results

17p+He spectrum
The p+He spectrum shows aspectral hardening at ~ 600 GeV
and a softening at ~ 25 TeVICRC 202
Measurem 1 – Francesca Alema(p+He) ene ent of the light com nno,
rgy spectru
pm with the onent
DAMPE
space mission

INDIRECT MEASUREMENTS
DIRECT MEASUREMENTS
The extension of the p+He spectrum
to higher energy is ongoing
20th Lomonosov conference, 19-25/08/2021

Francesca Alemanno on behalf of the DAMPE collaboration
The DAMPE space mission: status and main results18

Conclusions
The DArk Matter Particle Explorer, was launched in December 2015 in a sun-synchronous
orbit and it is smoothly taking data since then●Searching for gamma-ray lines we obtained constraints on the Dark Matter annihilation crosssection comparable with other experimental results and lower limits on DM decay lifetime●●●

Found ~ 220 gamma-ray sources with a preliminary 5-year analysis

Direct detection of a break at ~1 TeV in the electrons and positrons spectrum●Detection of a softening at ~14 TeV in the proton spectrum

First detection of a softening in the helium spectrum at ~34 TeV, suggesting a Z dependence●●●Ongoing the p+He analysis, to reach higher energy and build a bridge between direct andindirect measurements
Many analysis are ongoing including primary (C, O, Fe, ...) and secondary (Li, Be, B, …)
spectra, along with their ratio (B/C, ...)

Thank you for the attention!

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