<figure><img src="image_1.png" /></figure>

HAL
open science

Paarl AfricaUnderground Laboratory(PAUL)

Fairouz Malek

► To cite this version:

Fairouz Malek. Paarl AfricaUnderground Laboratory(PAUL). 26ème Congrès Général de la SFP, Société Française de Physique, Jul 2023, Paris, France. hal-05383620

HAL Id: hal-05383620

https://hal.science/hal-05383620v1

Submitted on 26 Nov 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

Public Domain
Paarl Africa Underground Laboratory(PAUL)

arXiv:2306.12083 [hep-ex]

Dr Fairouz Malek (Grenoble LPSC)

<figure><img src="image_2.png" /></figure>

26ème Congrès Général de la SFP

Session MC02

Paris –July 5, 2023
How did it start ?

<figure><img src="image_3.png" /></figure>
How has it been kicked off ?

<figure><img src="image_4.png" /></figure>
The context: Previous publications

2015: Towards the South African Underground Laboratory :

<figure><img src="image_5.png" /></figure>

Physics Procedia
Volume 61, 2015, Pages 586-590

<figure><img src="image_6.png" /></figure>

2019: Latest Updates on Developments of the
Underground Neutrino Facility in South Africa

<figure><img src="image_7.png" /></figure>

World Scientific
Connecting Great Minds

Towards the South African Underground
Laboratory (SAUL) ☆

S.M. Wyngaardt ª, R.T. Newman ª, R. Lindsay b, A. Buffler c, R. de Meijer b, P. Maleka d, J. Bezuidenhout e, R. Nchodu
f, M. van Rooyen ª, Z. Ndlovu ª

LABORATOIRE DE PHYSIQUE SUBATOMI

Subject

Journals

Books

Major Reference Works

Resources For Partners

Open Access

About Us

Help

Exotic Nuclei, pp. 478-485 (2019)

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /></figure>

No Access

Latest Updates on Developments of the Underground Neutrino Facility in South Africa

Z. Z. Vilakazi, S. M. Wyngaardt, R. T. Newman, R. Lindsay, A. Buffler, R. de Meijer, P. Maleka, J. Bezuidenhout, R. Nchodu, M. van Rooyen and Z. Ndlovu

<footnote>ª Department of Physics, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602</footnote>

<footnote>ᵇ Department of Physics, University of the Western Cape, Modderdam Road, Private Bag X17, Bellville, 7530</footnote>

<footnote>Department of Physics, University of Cape Town, Rondebosch, 7700, South Africa</footnote>

<footnote>d iThemba LABS, P.O. Box 722, Somerset West, 7129, South Africa</footnote>

<footnote>Military Academy, Private Bag X2, Saldanha, 7395</footnote>
<figure><img src="image_10.png" /><figcaption>Square Kilometer Array</figcaption></figure>

<figure><img src="image_11.png" /></figure>

<figure><img src="image_12.png" /><figcaption>iThemba LABS</figcaption></figure>

<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /></figure>
World Class Universities

<figure><img src="image_15.png" /><figcaption>Stellenbosch University</figcaption></figure>

<figure><img src="image_16.png" /><figcaption>University of Cape Town</figcaption></figure>

<figure><img src="image_17.png" /><figcaption>University of the Western Cape</figcaption></figure>
<figure><img src="image_18.png" /></figure>
<figure><img src="image_19.png" /></figure>
The Huguenot tunnel

<figure><img src="image_20.png" /></figure>

<figure><img src="image_21.png" /></figure>

<figure><img src="image_22.png" /></figure>

<figure><img src="image_23.png" /></figure>
<figure><img src="image_24.png" /></figure>

1300m Du Toitskloof mountain with ~800 m of rock overburden for the Huguenot tunnel
<figure><img src="image_25.png" /><figcaption>Fig 2: Pre-pilot bore geology</figcaption></figure>

<figure><img src="image_26.png" /></figure>

The range mostly consists of Table Mountain sandstone, an erosion-resistant quartzitic sandstone
# PAUL in the Huguenot Tunnel

The design of LSM-Modane was used for the purpose of the illustration

The future underground laboratory is currently being designed; It directly involves the company operating the Huguenot tunnel (SANRAL) since earthworks and infrastructure construction are planned over the next five to ten years.

<figure><img src="image_27.png" /></figure>
Gamma-ray mapping in the Huguenot tunnel, 2013
Phys. Proc. 61 (2015) 586-590

<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>

<figure><img src="image_30.png" /></figure>

The concentrations measured at three sites confirm that the level of radon is well below any degree of consideration, with a mean level of radon no more than ~50 Bqm⁻³
Mock up of PAUL
facility

<figure><img src="image_31.png" /></figure>

A possible 600m² laboratory (40x16x16 m³) in the Huguenot tunnel.

Courtesy: Joaquin Venturino (CNEA), April 2023.
# Lab Depth (mwe) vs Decreasing cosmic-ray muon flux

<figure><img src="image_32.png" /></figure>

For PAUL, it is only an estimate as the cosmic-ray muon flux is not yet well measured, nor the real rock overburden known exactly (~800 m, ~2000 mwe)
# Potential of Astroparticle research

**The challenge** is to develop detectors with very low energy thresholds and excellent control over detector backgrounds.

## Technology

* ✓ Charge Coupled Devices (CCDs), Skipper-CCD (SENSEI, DAMIC, OSCURA)

* ✓ Solid-state cryogenic detectors (Ge, Si, ..), operating at T<15 mK, (Edelweiss)

* ✓ Noble Liquid target (Xe, Ar)

<figure><img src="image_33.png" /></figure>
Other Research Purposes of great interest in ZA

* Measurement of **extremely low radiation levels**. These very sensitive detectors, able to detect levels of radiation a millionth of the natural radiation of the human body. Researchers involved in this work can contribute to many needs in South Africa for accurate measurements, such as the detection of the radioactive gas radon that has been identified as a major radiation hazard in South African underground mines.

* The research of **endolithic bacteria** and technologies for bio-leaching

* **Astrobiology**, examining the impact of radiation (or the lack of it) to evolutionary processes or formation of bio-aerosols.

* In glaciology, the study of **ice samples from the Arctic, Antarctic** etc. allows mapping of the **evolution of climatic parameters** and contamination both in space and over time for the last centuries. The measurement of 137Cs and 241Am is the only way to get a precise dating of ice.

* The Cape Supergroup (in Natal and the Northern Transkei), where the lab would sit, has been identified as a region of interest for **geothermal research**.
Conclusion on PAUL

PAUL is foreseen as an open **international laboratory**, a unique opportunity for Africa devoted to the development of a
competitive science in the region. It has the advantage that the location, **the Huguenot tunnel, exists** already and the
geology and the environment of the site is appropriate for an experimental facility.

Perform an experiment of direct dark matter detection in an underground laboratory located in the Southern Hemisphere is to compare the eventual systematic errors or modulation with respect to the same detector in the Northern Hemisphere. Any systematic error or annual modulation correlated to a seasonal variation will have an opposed phase, giving the opportunity to discriminate them with respect to a dark matter signal. It also opens different regions of parameter space when searching for daily modulations

The other advantage to build an UL facility in South Africa is to **combine the direct detection with indirect dark matter detection from radio astronomy** surveys that South Africa is leading (SKA, MeerKAT, etc.). Therefore, the strong synergy between the astrophysical (indirect) probes and Paarl Africa Underground Laboratory (direct probe) can jointly measure and constrain dark matter effect, which may shed lights on new physics.
Publications and communications in 2023

June 21st: arXiv:2306.12083 [hep-ex]

Paarl Africa Underground Laboratory

Robert Adam<fnref n="5" />,<fnref n="1" />, Claire Antel<fnref n="14" />, Munirat Bashir<fnref n="23" />, Driss Benchekroun<fnref n="18" />, Xavier Bertou<fnref n="20" />, Markus Böttcher<fnref n="8" />, Andy Buffler<fnref n="7" />, Andrew Chen<fnref n="4" />, Rouven Essig<fnref n="22" />, Jules Gascon<fnref n="12" />, Mohamed Gouighri<fnref n="19" />, Trevor Hass<fnref n="1" />, Gregory Hillhouse<fnref n="6" />, Abdeslam Hoummada<fnref n="18" />, Ansyn John<fnref n="1" />, Pete Jones<fnref n="3" />, Youssef Khoulaki<fnref n="18" />, Luca Lavina<fnref n="13" />, Lerothodi Leeuw<fnref n="2" />, Mantile Lekala<fnref n="9" />, Robert Lindsay<fnref n="2" />, Roy Maartens<fnref n="2" />, Yin-Zhe Ma<fnref n="1" />, Fairouz Malek<fnref n="11" />,*, Peane Maleka<fnref n="3" />, Jacques Marteau<fnref n="12" />, Rachid Mazini<fnref n="21" />, Thebe Modupe<fnref n="8" />, Bruce Mellado Garcia<fnref n="4" />, Marcello Messina<fnref n="15" />, Lumkile Msebi<fnref n="2" />, Chilufya Mwewa<fnref n="26" />, Zina Ndobeni<fnref n="5" />,<fnref n="7" />, Richard Newman<fnref n="1" />, George O'Neill<fnref n="16" />, Fabrice Piquemal<fnref n="15" />, Lydia Roos<fnref n="13" />, Daniel Santos<fnref n="11" />, Silvia Scorza<fnref n="11" />, Fodor Simkovic<fnref n="24" />, Ivan Stekl<fnref n="25" />, Yahya Tayalati<fnref n="17" />, Smarajit Triambak<fnref n="2" />, Zeblon Vilakazi<fnref n="4" />, Shaun Wyngaardt<fnref n="1" />, JJ van Zyl<fnref n="1" />

Workshop, congress and conferences

1)- Underground Labs Workshop at Aussois: June 21-23

2)- French Physics Society General Congress, Paris, 3-7 July

3)- EAS Crakow, July 10-14

4) High Energy Astrophysics in Southern Africa (HEASA) July 31st

5) TAUP 2023, August 28 – September 1, 2023

6) African Nuclear Physics Conference, 29 Nov – 3 Dec in Kruger National Park.

<footnote n="1">¹Stellenbosch University-South Africa;</footnote>

<footnote n="2">²University of the Western Cape-South Africa;</footnote>

<footnote n="3">³Themba LABS-South Africa;</footnote>

<footnote n="4">⁴School of Physics, University of the Witwatersrand Johannesburg-South Africa;</footnote>

<footnote n="5">⁵Square Kilometre Array Observatory-South Africa;</footnote>

<footnote n="6">⁶Botswana International University of Science and Technology-Botswana;</footnote>

<footnote n="7">⁷University of Cape Town-South Africa;</footnote>

<footnote n="8">⁸North West University Potchefstroom-South Africa;</footnote>

<footnote n="9">⁹The University of South Africa;</footnote>

<footnote n="10">¹⁰LP2I, CNRS-IN2P3, Université Bordeaux-France;</footnote>

<footnote n="11">¹¹LPSC, CNRS-IN2P3, Université Grenoble Alpes-France;</footnote>

<footnote n="12">¹²IP2I, CNRS-IN2P3, Université Claude Bernard Lyon-France;</footnote>

<footnote n="13">¹³LPNHE, CNRS-IN2P3, Sorbonne Université Paris-France;</footnote>

<footnote n="14">¹⁴Université de Genève-Switzerland;</footnote>

<footnote n="15">¹⁵LNGS, Gran-Sasso-Italy;</footnote>

<footnote n="16">¹⁶European Spallation Source ERIC, Lund, Sweden;</footnote>

<footnote n="17">¹⁷Mohammed V university of Rabat-Morocco;</footnote>

<footnote n="18">¹⁸Hassan II university of Casablanca-Morocco;</footnote>

<footnote n="19">¹⁹Ibn Tofail University of Kenitra-Morocco;</footnote>

<footnote n="20">²⁰Centro Atómico Bariloche, CNEA/CONICET-Argentina;</footnote>

<footnote n="21">²¹Institute of Physics, Academia Sinica, Taipei-Taiwan;</footnote>

<footnote n="22">²²Stony Brook University, USA;</footnote>

<footnote n="23">²³Ibrahim Badamasi Babangida University-Nigeria;</footnote>

<footnote n="24">²⁴Comenius University Bratislava-Slovakia;</footnote>

<footnote n="25">²⁵IEAP CTU Prague-Czechia;</footnote>

<footnote n="26">²⁶Brookhaven National Laboratory, USA.</footnote>

<footnote>*Contact editor: fmalek@in2p3.fr</footnote>