150618 AEGIS Sandaker - NuPECC

Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy

AEGIS

15.6.2018 - University of Oslo - H. Sandaker

We observe a matter-antimatter asymmetry in the Universe • We expect there to be produced equal amounts of matter and

antimatter in the big bang but today we only observe matter • We search for the origin of this asymmetry

➡ Quantum theory (CPT) violations? ➡ Gravitation asymmetries? ➡ Other possibilities?

• Anti-matter experiments probing gravitation ➡ AEGIS ➡ GBAR ➡ ALPHA

AEGIS experiment - Importance of anti-matter research

Main goal of AEGIS is to test the Weak Equivalence Principle stating that all bodies fall with the same acceleration independent of mass and composition and to perform spectroscopy measurements with anti-Hydrogen



AEGIS experiment - Principle

• Positronium excitation Ps(n = 1) + Laser fields → Ps(n ∼ 30) • Charge exchange at low energies: Ps(n ∼ 30) + H ̄ − → H ̄ (n) + e−

• Manipulation and acceleration of excited anti-hydrogen Rydberg atoms in time depend. fields

• Deecitation H ̄ (n) → H ̄ (n = 1) • Annihilation of ground state anti hydrogen in the detector

Pulsed !

AEGIS experiment - at AD at CERN


AEGIS experiment - apparatus

The AEGIS Experiment proposal (Antimatter Experiment, Gravity, Interferometry, Spectroscopy) • Very first production of a pulsed cold beam of anti-Hydrogen (T~ 100 mK) • Measurement of the beam deflection with a Moire reflectometer (grating pitch ~ 40 um) • g measurement with 1% accuracy on anti-Hydrogen


AEGIS experiment - AD hall


AEGIS collaboration - about 80 authors


Norwegian Contributions to AEGIS - Research Overview

2. Development of annihilation detectors

4. Novel beamline GRACE

6. Common tasks (e.g. testbeam)

5. Positronium research

3. Software and simulations

1. Antiproton annihilation studies

7. Local infrastructure in Norway


Norwegian contribution - Example results

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N. Pacifico et al. NIM A - DOI: 10.1016/j.nima.2014.06.036 etc.

1. Antiproton annihilation studies • MIMOTERA: First (successful) measurement of

antiproton annihilation directly on a segmented silicon sensor.

• Silicon strip: Observation of effects due to space plasma (“volcano” effect) at lower bias voltage, sensitivity to different annihilation products can be tuned through the thickness

• ATLAS 3D: Thicker sensor allows observation of secondary prongs, pions distringuisable from heavier fragments , - production saturation

Thanks to MIMOTERA and ATLAS and others



3. Software and Simulations - Studies of annihilation in a Timepix3 detector

Thanks to TIMEPIX et al.

“Antiproton tagging and vertex fitting in a Timepix3 detector” S. Aghion et al 2018 JINST 13 P06004


• Building a position sensitive strip detector to measure the annihilation of anti-Hydrogen

• Initial requirements : - ~ 10 µm precision (25 µm pitch) - < 77 K operation - ≤ 1ms time resolution - 20 x 20 cm2 area

• Additional new requirements : ➡ max 50 um thickness to avoid

scattering ➡ vacuum separation window

(UHV - UV) ➡ 10 x 8 cm2 area

2. Development of annihilation detector - Novel strip detector


15.6.2018 - University of Oslo - H. Sandaker Thanks to Chloe and Tim

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AEGIS experiment - Example result

• One electrode bends the low energy anti-protons and the high energy particles, heavy fragments (background) goes straight

• Two Einzel lenses for focussing • 300 um Timepix3 detector • First measurements with this new setup last

week, test-beam ongoing

Result: single anti-protons at keV energies

4. Novel beamline GRACE


AEGIS experiment - Example result


5. Positronium Research

PhDs: Helga Holmestad (UiO), 2014-2018 (Stapnes/Sandaker/Røhne) Angela Gligorova (UiB), 2012-2015 (Sandaker/Pacifico/Doser) Postdoctor: Lillian Smestad (CERN), 2015-2018 Researchers: Torkjell Huuse (UiO), 2012-2015 Nicola Pacifico (UiB), 2012-2015 University staff: UiO: Ole Dorholt, David Bang (ELAB), UiO: Ole Røhne, Heidi Sandaker (High Energy Physics) UiB: Jan Petter Hansen (Atomic physics) UiB: Heidi Sandaker (Subatomic Physics), end 2018

Industrial partners: SINTEF: Ozhan Koybasi et al. IDEAS: Gunnar Mæhlum et al.

Norwegian Contributions to AEGIS - Collaboration


Norwegian Contributions to AEGIS - Funding

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 …

RCN: CERN related research project: ~2 MNOK

RCN: Personal postdoctor grant (Smestad): ~2.4 MNOK

RCN/UiB: FRINATEK Research project ~10.2 MNOK

BRF/UiB: Bergen Research Foundation grant

UiB: PhD Quota Scholarship

PhD student finished


Physics Run April 2018

AEGIS experiment - Future plans

Building 2nd generation detectorsRefurbishing of lab

Project period

Test of 2nd generation detectors (sources)

Contributions to Testbeam

Future of AEGIS Norway meeting

Final results for current project

Previous project



Education and Outreach

Slide from L. Smestad

Backup

AEGIS experiment - Current plans

• New clean room, thanks to the UiO MN faculty and the FI • Currently refurbishing the new laboratory for better detector development • Novel bonding machine arrived, the first in a series of new equipment, which is important

for the current work on AEGIS • Next step: We have material to build more silicon strip sensors, 2nd generation

3. Improved infrastructure in Oslo

UiO FI Cleanroom - will be used for ATLAS upgrade as well as AEGIS etc.

Documents

150618 AEGIS Sandaker - NuPECC