Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
Philip von Doetinchem I. Phys. Inst. B, RWTH Aachen University
Hausseminar, Aachen –
6th of June 2008
Search for Antiparticles in Cosmic Raysin Space and the Earth’s Atmosphere
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 2
Overview•
cosmic
ray
physics
in the
GeV-TeV
range
•
the
AMS-02 detector
for
the
ISS in Space:–
anticoincidence
counter
•
qualification
of hardware•
integration
•
analysis
–
prospects
for
AMS-02
•
the
PEBS detector
in Earth‘s
atmosphere:–
properties
of Earth‘s
atmosphere
and magnetic
field
–
simulation
of cosmic
ray
measurements
at the
Southpole–
prospects
for
PEBS
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 3
Particle & Astro
Physics
• particle
physics
& astrophysics
are
merging• use
particle
physics
methods
in astrophysics and get
input
to particle
physics
from
astrophysics
• important
observations
cry
for
explanations:– Dark
matter exists! What
is
the
nature? Supersymmetry, Kaluza-
Klein,…– Where
does
the
asymmetry
between
matter and antimatter in the
universe
come from?– …
WMAP 5 years
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 4
Cosmic Rays
kinetic Energy [GeV]-110 1 10 210
-1 s
r-1
s-2
m-1
GeV
Flu
x
-510
-410
-310
-210
-110
1
10
210
310
410
AMS-01 protons
AMS-01 helium
AMS-01 electronsHEAT 94/5 positrons
AMS-01 positrons
EGRET photons
IMAX antiprotons
Caprice 94 antiprotons
Caprice 98 antiprotonsBESS 95/97 antiprotons
BESS 02 antiprotons
= 441.641 MVΦsolar Modulation:
)αg
ald
ef 5
9927
8 / 5
9929
8(
protonheliumelectronpositronphotonantiproton
• learn
about
sources, acceleration, propagation, age, grammage
of matter, halo
size,…• good agreement
of models
in the
GeV-TeV
range
for
particles, some
unexplained features
in antiparticle/photon
spectra
AMS-02PEBS
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 5
Positrons & Antiprotons
• no primary
sources
for
positrons
and antiprotons
are
known• sensitive to new
physics: dark
matter annihilations
e.g. from
new
particles
in supersymmetric
or
Kaluza-Klein
Theories
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 6
Antihelium2 different appoaches
for
the
explanation
of the
baryon asymmetry:
• dynamically: large CP violation
is needed
• separation
of matter and antimatter in the
early
universe
measurement:• bound
on antihelium
gives
constraint
for
the
distance between galaxies
and antigalaxies
(NO(!) production
of antihelium
in the
matter universe
possible)
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
1 10 102
103
An
tih
eliu
m/H
eliu
m F
lux R
atio
(9
5%
C.L.)
Rigidity (GV)
(a) Buffington etal. 1981
(b) Golden etal. 1997
(c) Badhwar etal. 1978
(d) Alcaraz etal. 1998
(e) Sasaki etal. 2001
(a)
(b)(c)
(c)
(d)
(e)
AMS-02 3 Years
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 7
The AMS-02 Detector
artist
view
of AMS-02 on the
International Space
Station
> 2010
AMS-02 in the
clean room
@ CERN
3m7t
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 8
AMS-02 Overviewgoals of AMS-02:
•
precise spectroscopy of cosmic rays without interactions in the
atmosphere on the ISS• measurement/bounds on antimatter• indirect dark matter search
subdetectors:
Transition Radiation Detector (TRD)• classify particles by γ=E/m
Time of Flight (ToF)• trigger, velocity, dE/dx
Tracker + supraconducting
Magnet (1T)• track reconstruction, momentum, dE/dx
Anti-Coincidence Counter (ACC)• event selection next slide
Ring Image Cherenkov Detector (RICH) • precise velocity mesaurement
Electromagnetic Calorimeter (ECal) • shower shape and energy determination
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 9
Important Events for the ACC
ACC ACC
rejection of internal interactions rejection of external particles
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 10
ACC System•
small ACC inefficiency needed (<10-4) for measurement of antimatter with very clean single tracks
•
reduce trigger rate, fast detector (ns): e.g. south atlantic anomaly
WLS fiber Clear fiber
Charged particleCoupling
PMT
WLS fiberClear fiber
Coupling
Scintillator
PMT
PMT box,small B pos.
clear
fibers
scintillator
panels
2 panels
share
1 lower
and 1 upper
PMT
PMT box,small B pos.
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 11
Light Signals
PMT quantum efficiency
scintillator
with WLS fibers
attenuation of clear fiber
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 12
ACC Hardware Parts
panel side
PMT side
16 Y-shaped Toray clear fiber cables
16 Hamamatsu fine mesh PMTs,
B tolerant (0.5T 65% gain)
16 Bicron BC414 Scintillator Panels with inlaying Kuraray wave length shifting fibers
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 13
ACC Panel Production
finished
panel
curing
of glue
machining
of panel
glued
panel
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 14
adc200 400 600 800 1000
entr
ies
[#]
1
10
210
310
adc200 400 600 800 1000
entr
ies
[#]
1
10
210
310
410channel 0
channel 1
Panel Classification
cosmics LED
N pe=QCQLED
σ LED2
panel distribution
Entries 20Mean 18.71RMS 1.832
number of photo electrons[#]10 12 14 16 18 20 22 24
entr
ies
[#]
0
2
4
6
8
10
panel distribution
Entries 20Mean 18.71RMS 1.832
calculation of photo electron number:•
measurement of MOP with cosmics
•
calibration with LEDs implemented in panels
QC QLED test of all panels
material
photo elec.AMS-01
1.0cm
20
AMS-02
0.8cm
19
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 15
Coupling: WLS to Clear
Fiber
• acceptance
angle matching
of wavelength
shifting
fiber
and clear
fiber
is
important• WLS: wide
distribution
due
to reabsorption
is
also responsible
for
large attenuation
angle [deg]-60 -40 -20 0 20 40 60
entr
ies
[#]
0
100
200
300
400
500
600x Profile
y Profile
angle [deg]-60 -40 -20 0 20 40 60
entr
ies
[#]
0
100
200
300
400
500
600x Profile
y Profile
wavelength shifting fiber:
0.9dB/m
clear fiber: 0.15dB/m
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 16
Space Qualification -
PMTs
time [h]0 5 10 15 20 25 30 35 40 45
tem
per
atu
re [
deg
C]
-40
-20
0
20
40
60
Temperature requirements:operative: -30 -
+45 °C
non-operative: -35 -
+50 °C
TVT tank
PMTs
PMTs
PMTs did not changewithin 5% after Space
Qualification
random frequency spectrum: 3.3g
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 17
PMT Selection for Flight
time [s]-0.14 -0.12 -0.1 -0.08 -0.06 -0.04
-610×
amp
litu
de
[V]
-0.05
-0.04
-0.03
-0.02
-0.01
0
channel 26
channel 28
typical signal shape
classification with gain and p.e. number
mounting in light and glass dust tight box
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 18
Complete System Testtest of complete chain:
panel + clear fiber + PMT show good results
(mean: 16 photo electrons)
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 19
LED preintegration/system test0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
entr
ies
[#]
0
5
10
15
20
25
30
35
40
45entries: 159
mean: 0.99
width: 0.08
Preintegration
successful preintegration:99 ±
8 %
LED test comparison (after/before)
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 20
Inefficiency
Studies: Testbeam
-
Setup
test of slot and central region
slot
central
slot
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 21
Testbeam
–
Inefficiency Measurement
position [cm]0 5 10
sig
nal
rat
io
0.5
0.6
0.7
0.8
0.9
1
+ 1.0021.000 pos - 10.636cm
0.061cmratio =
highest ADC counts from both PMTs on one panel for each event
slot14.3 mm from slot
2.6 mm from slot
fit to MOP position
central
cent
ral
slot
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 22
Signal Ratios
position [cm]0 10 20 30 40
sig
nal
rat
io
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
1.05 pos+1-1ratio = -0.0076cm
channel 3 / channel 40 0.5 1 1.5 2 2.5 3
entr
ies
[#]
1
10
210
entries: 1121
mean: 0.99
RMS: 0.40
ratio of both PMT MOP signals on one panels vs. position
distribution of signal ratios at the central position
estimation of hit positioncentral
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 23
Signal Model
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
width [cm]-40 -30 -20 -10 0 10 20 30 40
len
gth
[cm
]
-40
-30
-20
-10
0
10
20
30
40
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
width [cm]-40 -30 -20 -10 0 10 20 30 40
len
gth
[cm
]-40
-30
-20
-10
0
10
20
30
40
model for relative signal behaviour of one PMT
model for relative signal behaviour for the highest
value of both PMTs
PMT
PMT
PMT
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 24
Flight Electronics2 branches
of signal
processing:
• fast veto
decision
for
level1 trigger
with
discriminator
threshold• charge
and time measurement
after
trigger
(ADC, TDC)
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 25
Flight
Electronics: Calibration
s]μdelay [0 5 10 15 20 25 30 35 40
AD
C c
ou
nts
[#]
0
100
200
300
400
500
600
700
800 60pC12pC2pC
, 5nFΩtest pulse, Gain 25, 1.2k
Threshold0 50 100 150 200 250
Vo
ltag
e [m
V]
0
10
20
30
40
50V = 0.20 thr+ 1.76
ADC counts [#]0 500 1000 1500 2000
char
ge
[pC
]
0
100
200
300
400
500
600
700
800
, 5nF, side AΩtest pulse, Gain 25, 1.2k
time delay scan to get to the maximum signal of the ADC
gauging of ADC charge measurement with test pulses: high resolution for small charges
calibration of thresholds for the discrimination in the TDC
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 26
Flight Electronics
ACC0 / ADC counts [#]0 50 100 150 200 250 300
AC
C1
/ AD
C c
ou
nts
[#]
0
50
100
150
200
250
300
-110
1
10
•
2 PMTs
(ACC0/1) connected to one panel
•
no event missed out of 10000 by using the highest of both values
3RMS of pedestal
ADC counts [#]0 100 200 300 400 500 600 700 800 900 1000
entr
ies
[#]
1
10
210
310
410 ACC 0
ACC 1
ACC0+WLS
ACC1+WLS
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 27
Isotropic Particle Distribution
•
beamtest: straight infall to panel
•
space: isotropic particle distribution leads to longer
path lengths in
scinitillator [deg]θangle 0 20 40 60 80
sig
nal
rat
io
1
2
3
4
5
6
isotropic particle toy MC distribution of travelled
paths in scintillator thickness: 0.8cm
lab measurement of rel. signal vs. angle:good agreement
with theory
theory
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 28
Inefficiency Model
• Data:
Mean inefficiency for one complete ACC
panel
with complete system test results and isotropic particle distribution and testbeam
electronics:
5⋅10-5
•
Simulation: use of testbeam
spectra with extrapolation to small values, system test, flight electronics, position measurements, isotropic particle distribution, smearing of signal values: 5⋅10-6
X position [cm]-40 -30 -20 -10 0 10 20 30 40
Inef
fici
ency
-810
-710
-610
-510
-410
-310
-210MC: LeCroy
MC: SFEA2
Y position [cm]-10 -5 0 5 10
Inef
fici
ency
-810
-710
-610
-510
-410
-310
-210TestbeamMC: LeCroy
MC: SFEA2
slot slot
central central
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 29
AMS-02 Cosmics: EventdisplayAMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008AMS Event Display Run 1210153173/ 76281 Wed May 7 11:43:06 2008
DAQ
Level1
Header
x y
z
Front
DAQ
Level1
Header
xy
z
Side
DAQ
Level1
Header
x y
z
Front
DAQ
Level1
Header
xy
z
Side
1.000 Coo=(-62.33,-20.61,-52.99) AntiC=-34.00 ±=-1.000β=5.98 Q= 1 φ=0.63 θ nan ± 1e+21 M= 0± Particle TofTrd No 0 Id=2 p= -1e+07
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 30
Event Selection
time of hit in TDC for 1 hit per eventrequire for selection at least one hit within 80ns of trigger
matching of TRD track with tracker:• at least
two tracker hits within 0.25cm•
one hit within 0.25cm in last layer before extrapolated hit position in ACC
| [cm]TR-hitTRD
tracker: |hit0 10 20 30 40 50 60
entr
ies
[#]
1
10
210
310
410
510
610
710entries: 8817918
effect of multiplexing in x direction
Tracker
layer
5 distance (Δx2+Δy2)1/2
trigger
noisenoise
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 31
AMS-02 Cosmics
cos(zenith)0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
entr
ies
[#]
1
10
210
310
410
510
610ACC: 13066
TRD: 4978989
zenith angles for all good TRD and for ACC events surviving all cuts
highest ADC value for each event surviving tracker cuts: no events below 30 (3RMS)
Inefficiency < 7.7⋅10-5
ADC counts [#]0 1000 2000 3000 4000
entr
ies
[#]
1
10
210
310
410entries: 13066
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 32
AMS-02 Cosmics: Signals
-110
1
10
[rad]φ-3 -2 -1 0 1 2 3
AD
C c
ou
nts
[#]
0
500
1000
1500
2000
2500
3000
3500
4000
entries: 12987
-110
1
10
[rad]φ-3 -2 -1 0 1 2 3
AD
C c
ou
nts
[#]
0
500
1000
1500
2000
2500
3000
3500
4000
entries: 9812
not very well configured: • mix of EM, QM and FM• different settings and conditions
upper PMTs lower PMTs
12 3
4
5
678
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 33
-210
-110
1
[rad]φ-3 -2 -1 0 1 2 3
z [c
m]
-100
-50
0
50
100
entries: 81
Position Matching: ACC/Track
5 6 7 8 1 2 3 4 -110
1
10
ACC sector [#]1 2 3 4 5 6 7 8
AC
C s
ecto
r fr
om
Tra
ck [
#]
1
2
3
4
5
6
7
8
entries: 81
position of hits below 30 very close to adjacent panel:• adjacent panels show normal signals • TRD/tracker matching not precise enough• scattering in detector
position of hits with small signals
no events missed out of 13000 ACC events
considering the complete ACC
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 34
Antihelium with AMS-02
larger angular acceptance of ACC
than TOF
• check for
the
ability
to measure
particles
between
triggers
with
the
ACC which
could
spoil
the
charge
determination
• toy
MC with
TOF, Tracker and ACC
with
isotropic
particle
distribution
and without
magnetic
field
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 35
Antihelium with AMS-02
external eventTOF trigger event
distance between hits is interesting for charge measurement efficiency
TOF
TOF
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 36
Antihelium with AMS-02
number of close hits0 1 2 3 4 5 6 7 8
pro
bab
ility
[%
]
-410
-310
-210
-110
1
10
210
310
|<0.05mACC-hitTOF
close hit: 0m<|hit |<0.05mACC-hitTOF
close hit: 0m<|hit
distance in tracker layers between TOF trigger events and external events
probabilty
for close hits (<5cm) not longer than 80ns from trigger @ 2kHz
external
hits
can
be
nearly
completlyexcluded
to spoil
charge
measurement
ext
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 37
Antiprotons with
TRD, TOF and Tracker
Energy [GeV]1.5 2 2.5 3 3.5 4 4.5 5
Ele
ctro
n R
ejec
tio
n
1
10
210-efficiencyp90%
Energy [GeV]0 50 100 150 200 250
Ele
ctro
n R
ejec
tio
n1
10
210
-efficiencyp70%
electron rejection from time resolution of TOF (100ps) due to different masses
electron rejection from TRD from Lorentz factor γ=E/m due to different masses
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 38
Antiprotons with
TRD, TOF and Tracker
Energy [GeV]1 10 210
]-2
m-1 s
-1sr
-1F
lux
[GeV
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
410
AMS01 protonsIMAX antiprotonsCaprice 94 antiprotonsCaprice 98 antiprotonsBESS 95/97 antiprotonsBESS 02 antiprotonscombined antiprotons
, AMS, 1095 dayspp, AMS, 1095 days
conv. Galprop
Energy [GeV]1 10 210
]+/p
pA
nti
pro
ton
Fra
ctio
n [
-510
-410
-310
IMAXCaprice 98
Caprice 94
BESS 95/97
BESS 02
HeatPamela (preliminary)
AMS, 1095 days
AMS, sys. error
Galprop + DM
DM, DarkSUSY
conv. Galprop
= 1560 GeV0
= 262 GeV, m1/2m
= 00
>0, Aμ= 40, βtan
DM signal boost factor: 1.0
measurement over 3 years with:• acceptance = 0.4m2sr• 63% efficiency• 10% systematic errors to the knowledge of detector properties• tracker resolution is not important in this energy range (σp
=0.04%/GeV⋅p⊕1.5%)
good measurement of antiprotons without electromagnetic calorimeter possible
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 39
PEBS –
Cosmic
Rays in the
Atmosphere
PositronElectronBalloon
Spectrometer
detector
proposal:• cosmic
ray
measurements
@ North-
or
Southpole• balloon
in 40km altitude
in the
atmosphere
and magnetic
field
detector
properties:• flight
time: 100days (total)
• acceptance: 0.4m2sr• magnetic
field: 1T
• weight: < 2t
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 40
Analysis Scheme
PLANETOCOSMICS
produce spectra of galactic cosmic ray
GALPROPDarkSUSY
solar Modulationforce field approximation
isotropic distributionin 40km height
Earth’s magnetic field and atmosphere(IGRF, NRLMSIS00)
compare secondary muonswith BESS @ Ft. Sumner, TX
verify simulation
simulate at South Poleextract galactic fluxes
calculate errors
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 41
Air Shower• use
of program
package:
PLANETOCOSMICS
based on GEANT4
• atmospheric
model: NRLMSISE00
• magnetic
field: IGRF 2005
• detection
planes around
the Earth
• start particles
in 500km altitude
10GeV proton
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 42
Properties
of the
Atmosphere
Altitude [km]0 10 20 30 40 50 60 70 80
Tem
per
atu
re [
deg
Cel
siu
s]
-120
-100
-80
-60
-40
-20
0
20
Altitude [km]0 10 20 30 40 50 60 70 80
]2d
epth
[g
/cm
-210
-110
1
10
210
310
kinetic gas temperature of the atmosphere at latitude -75°,
December (Southpole)
depth (integrated density) of atmosphere for zenith angle =
0°, latitude -75°, December (Southpole)
10°C
3.7g/cm2
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 43
Radiation Lengths
cos(zenith)0 0.2 0.4 0.6 0.8 1
nu
mb
er o
f ra
dia
tio
n le
ng
th
0
0.5
1
1.5
2
2.5
number of crossed radiation lengths depends on zenith angle
distribution of crossed radiation lengths before 40km during
summer at Southpole
using an isotropic particle distribution
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 44
Magnetic Field
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 45
Geomagnetic Cut-off
azimuth [deg]0 50 100 150 200 250 300 350
zen
ith
[d
eg]
0
10
20
30
40
50
60
70
80
90
cut-
off
[G
V]
0
2
4
6
8
10
12
14
16
18
20
geomagnetic cut-off for particles with zenith angle = 0°
geomagnetic cut-off depends on zenith and azimuth at each
location
Ft. Sumner, Texas
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 46
BESS Muon
Data in Texas
Energy [GeV]1 10
]-2
m-1 s
-1sr
-1F
lux
[GeV
-210
-110
1
10
210237000 m, 4.7 g/cm
230000 m, 13 g/cm
2BESS 4.68 g/cm
2BESS 13.4 g/cm
good agreement
of simulated secondary muons
with BESS data
at Ft. Sumner
simulated angular distribution for muons
in 37km altitude
Simulation works, now
Southpole
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 47
Fluxes
in different Altitudes
integrated flux (1-130GeV): primary particles
integrated flux (1-130GeV): secondary particles
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 48
Detector Acceptance
cos(zenith)0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
]-1 s
-2m
-1F
lux
[sr
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
410primary positrons, 40000m
secondary positrons, 40000m
)detαcos(0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
En
trie
s [#
]10
210
310
410
angular distribution of secondary and primary positrons
angular acceptance of PEBS works as filter on secondaries
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 49
Atmospheric
Attenuation
in 40 km
total antiprotons / generated antiprotons
total positrons / generated positrons
atmosphere
is
electromagnetically
much
more
effective
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 50
Detector Properties
/ GeVBeamE50 100 150 200 250
Ele
ctro
n R
ejec
tio
n F
acto
r
10
210
310 70% e-Eff. 2x8 Layer
80% e-Eff. 2x8 Layer
90% e-Eff. 2x8 Layer
/ GeVBeamE50 100 150 200 250
Pro
ton
Rej
ecti
on
Fac
tor
10
210
310 70% e-Eff. 2x8 Layer
80% e-Eff. 2x8 Layer
90% e-Eff. 2x8 Layer proton/positron rejection
from TRD
electron/antiproton rejection
from TRD
electron/positron rejection
from tracker
electron/antiproton rejection from TOF
σp
=0.194%/GeV⋅p⊕2.3%
Ecal
rejectionsp+/e+
and e-/p-: 5000 (70% Efficiency)
Energy [GeV]1.5 2 2.5 3 3.5 4 4.5 5
Ele
ctro
n R
ejec
tio
n
1
10
210-efficiencyp90%
Energy [GeV]50 100 150 200 250 300
- e
→+ eP
rob
abili
ty E
-1310
-1210
-1110
-1010
-910
-810
-710
-610
-510
-410
-310
-210
-110
1
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 51
Total Number of Particles
Energy [GeV]1 10 210
[#]
PE
BS
N
1
10
210
310
410
510
610
710
810
910
1010, PEBS, 100 daysptotal
, PEBS, 100 days+total p
Energy [GeV]1 10 210
[#]
PE
BS
N1
10
210
310
410
510
610
710
810
910
1010, PEBS, 100 days+total e
, PEBS, 100 days-total e
protons
and antiprotons electrons
and positrons
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 52
Composition
Energy [GeV]1 10 210
[%]
-210
-110
1
10
210
, PEBS, 100 daysptotal
altitude, PEBS, 100 dayspprim. altitude, PEBS, 100 dayspsec.
, PEBS, 100 days-wrong e
, PEBS, 100 days-μwrong , PEBS, 100 days-πwrong , PEBS, 100 days+wrong p
Energy [GeV]1 10 210
[%]
-210
-110
1
10
210
, PEBS, 100 days+total e
altitude, PEBS, 100 days+prim. e
altitude, PEBS, 100 days+sec. e
, PEBS, 100 days+wrong p
, PEBS, 100 days-wrong e
antiprotons positrons
secondaryantiprotons
muons
pions
primaryantiprotons
electrons
primarypositrons
secondarypositrons
electrons
protons
using
the
according
rejections
and efficiencies
for
each
type
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 53
Antiprotons
Energy [GeV]1 10 210
]-2
m-1 s
-1sr
-1F
lux
[GeV
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
410
AMS01 protonsIMAX antiprotonsCaprice 94 antiprotonsCaprice 98 antiprotonsBESS 95/97 antiprotonsBESS 02 antiprotonscombined antiprotons
, PEBS, 100 dayspp, PEBS, 100 days
conv. Galprop
Energy [GeV]1 10 210
]+/p
pA
nti
pro
ton
Fra
ctio
n [
-510
-410
-310
IMAXCaprice 98
Caprice 94
BESS 95/97
BESS 02
HeatPamela (preliminary)
PEBS, 100 days
PEBS, sys. error
Galprop + DM
DM, DarkSUSY
conv. Galprop
= 1560 GeV0
= 262 GeV, m1/2m
= 00
>0, Aμ= 40, βtan
DM signal boost factor: 1.0
using
the
according
rejections
and efficiencies
for
each
typewith
systematic
errors
for
detectors
of 3% and 15% for
the
atmosphere
fluxes fraction
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 54
Positrons
Energy [GeV]1 10 210
]-2
m-1 s
-1sr
-1F
lux
[GeV
-710
-610
-510
-410
-310
-210
-110
1
10
210
310
410
AMS-01 electrons
AMS-01 positrons
HEAT 94/5 positrons
, PEBS, 100 days+e
, PEBS, 100 days-e
conv. Galprop
Energy [GeV]1 10 210
-+e+ e+ e
Po
sitr
on
Fra
ctio
n
-110 PEBS, 100 days
PEBS, sys. error
HEAT
AMS01
combined
Galprop + DM
DM, DarkSUSY
conv. Galprop
= 1560 GeV0
= 260 GeV, m1/2m
= 00
>0, Aμ= 40, βtan
DM signal boost factor: 100.0
using
the
according
rejections
and efficiencies
for
each
typewith
systematic
errors
for
detectors
of 3% and 15% for
the
atmosphere
fluxes fraction
Search for Antiparticles in Cosmic RaysPh. von Doetinchem Hausseminar 08/06/06 – p. 55
Conclusion•
ACC system for AMS-02 works!–
scintillators, clear fibers, PMTs: good
–
flight electronics: good–
preintegration
done!
–
cosmic test of AMS-02–
good inefficiency of about 10-5
for antimatter
search•
PEBS prospects are promising!–
atmospheric and magnetic simulations work fine
–
good capabilities to measure positrons and antiprotons and Southpole
or Northpole