Transcript ALPS II

Any Light Particle Search II
ALPS II @ DESY
Axel Lindner
DESY
IAXO workshop, Frascati, 18 April 2016
ALPS II motivation: a bibliometric look
> Key words “axion”, “relaxion”, “axion-like particle”, “WISP”
try to restrict analysis to “physics”
> WoS, Scopus
> Significant increase in WISP-related publications!
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 2
ALPS II physics motivation: theory
> Axion cosmology: arXiv:1508.06917 [hep-lat]
lattice QCD calculations are used to determine the amount of axion
Dark Matter today via the temperature dependence of the axion mass.
> Baryon genesis from the axion: Phys.Rev.Lett. 113 (2014) 17, 171803
this cold genesis requires a coupling of the Higgs to a new scalar with
O(100 GeV) mass (to be tested at LHC!).
> A naturally small electroweak scale: arXiv:1506.09217 [hep-ph]
could be explained by a cosmological Higgs-axion interplay.
The symmetry breaking scale fa may be at the same time the
see-saw scale explaining the active neutrino masses,
mA ~ mν ~ 1/fa , JHEP 1406 (2014) 037
There are viable theoretical models addressing fundamental problems in
cosmology and particle physics based on axion-like particles or other WISPS.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 3
ALPs in the sky (1)
> Axion-like particles might explain the apparent transparency
of the universe for TeV photons:
TeV photons may
“hide” as axions.
M. Meyer, 7th Patras Workshop on Axions, WIMPs and WISPs, 2011
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 4
ALPs in the sky (1)
> New FERMI limits on ALPS from search for irregularities
in the spectrum of NGC1275 (http://arxiv.org/abs/1603.06978):
Do we start to zoom into the properties of the axion-like particle
explaining the TeV transparency hint?
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 5
ALPs in the sky (2)
> Hints for ALPS from developments of stars (M. Giannotti, I. Irastorza,
J. Redondo, A. Ringwald, http://arxiv.org/abs/1512.08108):
Indications for “BSM energy losses”
of different kinds of stars could be
consistently explained by one
electron coupling
axion-like particle coupling to
photons and electrons.
It could be the same ALP as the one explaining
the “TeV transparency”.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 6
Purely laboratory experiments
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 7
ALPS I 2007-2010: our starting point
(PLB Vol. 689 (2010), 149, or http://arxiv.org/abs/1004.1313)
> Unfortunately, no light was shining through the wall!
laser hut
HERA dipole
3.5·1021 1/s
detector
< 10-3 1/s
> The most sensitive WISP search experiment in the laboratory (up to 2014).
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 8
The ALPS II challenge
> Improve on the
ALPS-photon-photon
coupling strength g
by > 1,000.
The experiment measures
a rate ~ g4:
> The experimental
sensitivity is to
increased by a factor
1012!
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 9
laser hut
> Laser with optical cavity to recycle laser power,
switch from 532 nm to 1064 nm,
increase effective power from 1 to 150 kW.
HERA dipole
> Magnet:
upgrade to 10+10 straightened HERA dipoles
instead of ½+½ used for ALPS I.
detector
> Regeneration cavity to increase WISP-photon
conversions, single photon counter
(superconducting transition edge sensor).
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 10
All set up in a clean environment!
Prospects for ALPS II @ DESY
ALPS II is realized in stages (JINST 8 (2013) T09001)
ALPS I:
basis of success was
the optical resonator
in front of the wall.
> ALPS IIa
Optical resonator to
increase effective
light flux by
recycling the laser
power
Optical resonator to
increase the conversion
probability
WISP→
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 11
ALPS II is realized in stages (JINST 8 (2013) T09001)
ALPS I:
basis of success was
the optical resonator
in front of the wall.
> ALPS IIa
The optics concept was invented three times independently:
• Hoogeveen F, Ziegenhagen T.
Optical resonator to
Nucl. Phys.Optical
B358:3resonator
(1991) to
increase the conversion
increase effective
• Fukuda Y, Kohmoto
T, Nakajima Si, Kunitomo M.
probability
light
flux by
Prog. Cryst.
Growth
Charact.Mater. 33:363 (1996)
recycling
the van
laser

• Sikivie P., Tanner
D.B.,
Bibber WISP→
K.
power
Phys.Rev.Lett.
98 (2007)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 12
ALPS II is realized in stages (JINST 8 (2013) T09001)
ALPS I
> ALPS IIa
> ALPS IIc
20 HERA dipoles, 200 m long
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 13
The ALPS II challenge
> Photon regeneration probability:
> ALPS II:
 FPC = 5000, FRC = 40000 (power build-up in the optical resonators)
 B = 5.3 T, l = 88 m (two times)
P = 6·10-23 , 30 photons per hour
P = 6·10-27 , 2 photons per month
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 14
ALPS II: main experimental challenges
> HERA dipole magnets:
straighten the cold mass cheap
and reliably to increase the
35 mm aperture to 50 mm.
> Optics:
construct and operate two 100 m
long optical resonators of high
quality which are mode matched
and aligned to better than
10 µrad.
> Detector:
characterize and operate a
superconducting Transition Edge
Sensor (25µm·25µm·20nm) at
80 mK to count single 1064 nm
photons.
DESY expertise, but
mostly retired experts only.
Adapt LIGO techniques,
AEI Hanover,
U. of Florida, DESY
DESY, HH, Mainz, in close
collaboration with
NIST (Boulder) and PTB Berlin
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 15
ALPS II optics
Production cavity, infrared
Wall
Regeneraton cavity, locked with green light.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 16
ALPS II optics
Production cavity, infrared
Wall
Regeneraton cavity, locked with green light.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 17
ALPS II optics
Production cavity, infrared
Wall
Regeneraton cavity, locked with green light.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 18
ALPS II optics
> Pound-Drever hall “locking“ to
compensate for seismic noise fluctuations.
ok
> Differential wavefront sensing for
auto-aligning the optical axis of the cavity.
ok
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 19
ALPS II optics
> Generate and
adapt 532 nm
light to control
the regeneration
cavity behind
the wall.
(ok)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 20
ALPS II optics
> Feed 532 nm light into the
regeneration cavity with “perfect”
filtering out 1064 nm light.
(ok)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 21
ALPS II optics
> Pound-Drever hall “locking“ to
compensate for seismic noise fluctuations.
(ok)
> Differential wavefront sensing for
auto-aligning the optical axis of the cavity.
(ok)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 22
ALPS II optics
> Design and build central breadboard with two
flat mirrors fixed and aligned to an accuracy
better than 10 µrad.
(ok)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 23
ALPS II optics
> Guide 1064 nm signal
photons into the detector
with “perfect” filtering out
532 nm light.
(ok)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 24
The photon source
The laser has been
developed for LIGO:
35 W, 1064 nm, M2<1.1
based on
2 W NPRO by
Innolight/Mephisto
(Nd:YAG (neodymiumdoped yttrium
aluminium garnet)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 25
The central optics
0,0006 mm
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 26
Status of optics (1)
Before late 2015 faulty cavity mirrors exceeding the roughness
specification prevented a stable cavity operation. New mirrors were
ordered to test the 20 m setup ALPS IIa with a confocal cavity:
Goals:
> Understand properties of the cavity.
> Be able to lock the cavity for “infinity”.
> Get the auto-alignment system into operation.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 27
Status of optics (2)
> Understand properties of the cavity.

There are 200 ppm
unexplained losses which
will probably vanish once
we operate the cavity in
vacuum.
> Be able to lock the cavity for “infinity”.
> Get the auto-alignment system into operation.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 28
Status of optics (3)
> Understand properties of the cavity.
> Be able to lock the cavity for “infinity”.


The seismic noise in the
ALPS IIa lab can be
handled by the control
system.
> Get the auto-alignment system into operation.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 29
Status of optics (4)
> Understand properties of the cavity.
> Be able to lock the cavity for “infinity”.
> Get the auto-alignment system into operation.



Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 30
Optics: next steps
> Implement the a simplified version of the central breadboard.
> Operate 10 m production cavity.
> Operate production cavity in vacuum.
> High power tests in vacuum.
> Implement prototype of central breadboard.
> Test the (simultaneous) operation of both cavities.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 31
Control loops for the ALPS II PC at work
control signal
error signal
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 32
Control loops for the ALPS II PC at work
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 33
ALPS II detector
Transition Edge Sensor (TES)
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 34
ALPS II detector
Transition Edge Sensor (TES)
ΔT  100 µK
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 35
ALPS II detector
Transition Edge Sensor (TES)
ΔT  100 µK
ΔR  1 Ω
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 36
ALPS II detector
Transition Edge Sensor (TES)
ΔT  100 µK
ΔR  1 Ω
ΔI  70 nA
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 37
ALPS II detector
Transition Edge Sensor (TES)
ΔT  100 µK
ΔR  1 Ω
ΔI  70 nA
> Expectation:
very high quantum efficiency, also at 1064 nm,
very low noise.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 38
ALPS II: Transition Edge Sensor (TES)
25 x 25 µm2
8 µm
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 39
ALPS II: Transition Edge Sensor (TES)
> Tungsten film kept at the transition to
superconductivity at 80 mK.
> Sensor size 25µm x 25µm x 20nm.
> Single 1066 nm photon pulses!
> Energy resolution 8%.
> Dark background 10-4 counts/second.
> Ongoing: background studies, optimize
fibers, minimize background from
ambient thermal photons.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 40
ALPS II: heterodyne detection under study in Florida
> Mix signal with a local oscillator and look for beat-signal.
> Strong requirements on phase stabilities.
Courtesy Guido Mueller
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 41
ALPS II schedule (rough)
2015
ALPS IIa
2016
2017
2018
2019
Install.
(without magnets)
Runs
risk assessments
ALPS IIc
Closure of the LINAC tunnel
of the European XFEL
under construction at DESY.
ALPS IIa today
ALPS IIc in 2019
in the HERA tunnel
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 42
ALPS II schedule (rough)
Latest input from QED VMB studies
on the ALPS IIc design!
2015
ALPS IIa
2016
2017
2018
2019
Install.
(without magnets)
Runs
risk assessments
ALPS IIc
Closure of the LINAC tunnel
of the European XFEL
under construction at DESY.
ALPS IIa today
ALPS IIc in 2018
in the HERA tunnel
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 43
The axion-like particle landscape
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 44
ALPS II sensitivity
> Well beyond current limits.
> Aim for data taking in 2019.
ALPS II
> QCD axions not in reach.
> Able to probe hints from
astrophysics.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 45
Beyond ALPS II
> Rough estimation with some crucial parameters:
Photon
>Exp.
QCD axions
not Photon
in reach. B
flux
E (eV) (T)
> Able to probe
(1/s) hints from
astrophysics.
3.5·1021
ALPS I
L
(m)
B·L
(Tm)
PB
reg.cav.
Sens.
(rel.)
Mass
reach
(eV)
2.3
5.0
4.4
22
1
0.0003
0.001
ALPS II
1·1024
1.2
5.3
106
468
40,000
1
0.0002
“ALPS III”
1·1025
1.2
15
400
6000
100,000
25-30
0.0001
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 46
Beyond ALPS II
> QCD axions not in reach.
> Could measure properties
of a lightweight ALPs
discovered by IAXO!
ALPS III
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 47
Summary
> In addition to axions, also axion-like particles (ALPs) are going strong.
 ALPs are expected in extensions of the Standard Model.
 Astrophysics phenomena might point at the existence of ALPs.
 ALPs might also constitute the dark matter.
> ALPS II has a sufficient sensitivity to discover axion-like particles or other
WISPs, especially in the region hinted at by astrophysics.
 ALPS II will conduct a first hidden photon search in 2017.
 The full experiment could be ready in 2019.
> On the longer run, options for an “ALPS III” should be explored.
> In WISP physics, haloscopes like IAXO and purely laboratory based
experiments like ALPS II nicely complement each other!
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 48
Lessons learned from ALPS II
It is fascinating physics nicely complementing
other particle physics enterprises:
> New ideas are realized by combining different expertise.
 Particle physics (DESY) and optics (LIGO) join forces.
> Young people have fun taking responsibilities at ALPS II.
 Four Ph.D. theses and two postdoc careers since the start in 2011.
 At present eight Ph.D. and six postdocs are at work.
> Funding works out!
 Once ALPS II preparation had started seriously, external contributions got approved!
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 49
ALPS II and IAXO: a likely case
> ALPS II discovery an axion-like particle.
 The coupling strength to photons will be determined.
 The mass might be measured or limited.
> IAXO will see such axion-like particles produced in the sun.
 Other couplings (electron, nucleon) could be probed.
 Solar physics cold be probed.
> With ALPS II and IAXO data we could narrow down the many
opportunities of beyond-the-standard-model theories.
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 50
ALPS II and IAXO:
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 51
ALPS II and IAXO: an equally likely case
> ALPS II does not see an axion-like particle.
> IAXO is baldy required to solve the astroparticle physics riddles
hinting at axion-like particles.
> With IAXO and ALPS III data we could narrow down the many
opportunities of beyond-the-standard-model theories.
Thank your for your attention!
Axel Lindner | ALPS II | IAXO Workshop April 2016 | Page 52