Photo by Gerry Kingsley

The SNOLAB underground laboratory is an expansion of the original SNO facility consisting of a large cavern housing the detector and ancillary spaces in mining drifts for the experiment and personnel infrastructure. The main level of the laboratory is located at the 6800 ft level of the mine with 2070 m of granitic rock overburden. The ambient rock temperature at this depth is 42C. Surface elevation at the site is 309 m above sea level. The surface topology is approximately flat. Access to the 6800 Level and SNOLAB is via 9 Shaft, located 1.4 km from the laboratory entrance. SNOLAB was designed to operate as one large clean room, in keeping with the successful approach used by SNO. Personnel entering the laboratory pass through showers and change into clean room clothing. Equipment entering the laboratory is either cleaned in a carwash before entering the lab or shipped underground in sealed clean containers that are opened after being washed and brought into the lab.

The SNOLAB expansion added an additional 6,300 m2 of excavations of which 3,700 m2 is clean room space attached to the existing facility. The clean/dirty boundary was moved for the expanded laboratory and some existing excavations were converted to additional clean space. The SNOLAB underground laboratory has 5,000 m2 of clean space. Of this, 3,100 m2 is experimental laboratory space. There is an additional 2,600 m2 of excavation outside the clean room used by SNOLAB for the service infrastructure and material transportation and storage. The clean spaces of the laboratory have shotcreted and painted walls, and painted concrete floors. Outside the lab most areas are bolted and screened but not shotcreted or painted. The material handling area immediately outside the laboratory entrance has concrete pads, and other areas have bare gravel on the drift floors.

SNOLAB construction took place in two phases. Phase I added a new laboratory entrance and service facilities (chiller, generator, waste water treatment), and new experimental areas: a network of drifts (Ladder Labs) for small and medium sized experiments and a large experimental hall (the Cube Hall) for a bigger experiment. Phase II consisted of an additional lager experimental space dubbed the Cryopit. The Cryopit is designed for an experiment using a large volume of cryogenic liquid and is isolated from the rest of the laboratory for safety in the event of a cryogen leak. In addition to the new laboratory space, there is also the existing SNO cavern and its associated Utility Drift and control room. As well, the relocation of the personnel facilities made the existing South Drift available for experiments or laboratory infrastructure. SNOLAB’s experimental spaces are listed below.

Laboratory Space Style Length (ft) Width (ft) Height Area SNO+ Cavern (Existing) Cavern Utility Drift Control Room 72 187 57 23 20 85 3848 4300 1140 South Drift (Existing) Drift 106 17 10/17 1802 Ladder Labs (Phase I) Drift C1 Drift C2 Drift B&D 105 75 360 20 25 15 12/19 17/25 10/15 2100 1875 5400 Cube Hall (Phase I) Hall Utility Drift Staging Area Control Room 60 115 45 62 50 20 16 18 50/65 10/17 10/15 10/16 3000 2300 720 992 Cryopit (Phase II) Cavern Utility Drift Staging Area Control Room 50 141 66 64 20 16 16 50/65 10/15 10/15 10/15 1963 2820 1056 1024 Existing Phase I Phase II 11090 27477 34340

SNOLAB Low Background Counting Facility

The SNOLAB Low Background Counting Facility was started in 2005 using facilities inherited from the Sudbury Neutrino Observatory (SNO). Currently, the facility provides services in low background counting using several facilities, including: gamma counting using ultra-lowbackgound germanium detectors, alpha counting using an XIA alpha counter, passive radon emanation, radon and thoron measurements with electrostatic counters and alpha-beta counters, X-ray Fluorescence (XRF) spectrometry, general gamma spectroscopy and consultation in low background materials and experiments. SNOLAB currently operates low background facilities in the SNOLAB surface laboratories and in the deep underground laboratory at the 6800 ft level (6000 m.w.e.) of the Creighton Mine, which is located near Sudbury, Ontario, Canada. The SNOLAB Low Background Counting Facility is open to users from the scientific community and associated industry. Please do not hesitate to contact us to determine how we can help with your projects.

Machine Shop

SNOLAB has a small clean machine shop in the underground lab.

This shop is of course intrinsically a dirty space, and is located in an isolated section of the laboratory to prevent particulates from getting into the rest of the lab. Presently, the shop contains a lathe, milling machine, drill press, cut off saws, and a band saw. SNOLAB’s machine shop provides multiple services through the Integration Department so that parts or equipment do not become cosmogenically radioactive through exposure to surface cosmic rays. The shop team can also help in the design of new experiments, construct simple equipment for science experiments, repair and modify existing laboratory equipment, and modify parts for background testing. The certified staff works with scientists, researchers, students and other stakeholders to create specialised equipment using drawings, photos and hand-drawn sketches.

Please contact the integration group at integration@snolab.ca with any inquiries or for further information.

Entrance and Personnel Facilities

The laboratory entrance is the transition from the dirty mine environment to the CLASS 2000 clean room interior of the laboratory. Initially adjacent to the SNO facilities, it was relocated to encompass the new experimental facilities. Its capacity was increased by a factor of two to accommodate the new lab’s larger work force. Material entering the laboratory transitions through a carwash where it is cleaned. Personnel entering the laboratory must shower and change into clean room clothing. In addition to showers and change rooms, the personnel facility has a lunchroom, meeting rooms and laundry facilities. The personnel drift also serves as SNOLAB’s refuge station in the event of an emergency in the mine. The personnel facilities are equipped to host 50 people underground during a shift.