SNOLAB Underground Status

SNOLAB Status
Upated 23 February 2007

SNOLAB is being excavated in two phases, In Phase I, a new large experimental hall called the "Cube Hall" and a network of smaller experimental spaces called the Ladder Labs are being excavated north of the existing SNO facility. Also in Phase I, the laboratory entrance will be relocated to the east of the SNO areas to form a common clean entrance to both the SNO and new facilities and an new "Utility Area" will be located east of the laboratory in the old mining area to house the lab's chiller (air conditioning system), an emergency generator and waste handling facility. In Phase II, another larger experimental space called the "Cryopit" will be excavated to the east of the Cube Hall. Presently, the excavation for Phase I is almost complete (shown in red in the figure below) while the funding for Phase II is being reviewed.

The extend of the excavation is shown in red in the above figure. All of the Phase I spaces have been excavated except for the lower part of the Cube Hall. This last volume comprises 8% of the total Phase I excavation and will be removed in a single blast sequence shortly. Shotcreting (the spray on concrete linear) is about 75% complete with the lab entrance done, most of the ladder labs and most of the approach to the Cube Hall. About half of the Cube Hall has been shotcreted. The concrete floors have started to be poured with the lab entrance completed and about 2/3 of the ladder labs. Installation of the steel work, interior walls, electrical, ventilation etc is expected to start in late spring or early summer.

Laboratory Entrance

	The laboratory entrance is the transition from the dirty mine areas to the clean room laboratory. It includes a rail yard for unloading shipments brought underground on a narrow gauge railway, a "carwash" to clean equipment and a personnel area including change rooms and showers for personnel.
	The region just inside the carwash. This area has now been shotcreted and the concrete floors poured. This area will be a "junction" where materials will be transfered to the different experimental spaces.
	A view of what will be the lunch room in the personnel area.
	This space will be the shower and change rooms. A mezzanine level will be installed and the men's showers and change rooms located on the lower level and the women's on the upper level.
	The Double Track Area at the laboratory entrance. This is a "dirty side" material handling area. From here it will go into a carwash where it will be unloaded from rail cars and cleaned prior to entering the clean laboratory.

Ladder Labs

	The Ladder Labs are a network of drifts (mining terminology for tunnels) intended to house several medium scale (several meter sized) experiments.
	The larger rail (north side) of the Ladder Labs looking east. This area is able to house a medium scale (4-5m size) experiment. The shotcrete finish has been applied to the back (roof) of the excavation.

Cube Hall

	The Cube Hall is a large hall located north of entry to the laboratory intended to house a large scale (10 m sized) experiment. In addition to the experimental hall there is a staging area, control room and utility room to support activities in the hall.
	Looking down into the Cube hall from the staging area. This view shows the Cube hall approximately 60% excavated. The shotcrete linear can be seen on the upper walls. A monorail runs along the centre of the back for lowering material into the hall.
	A view from down in the Cube Hall looking back up towards the entrance. The holes for the next "bench" are being drilled in preparation for blasting.

Cryopit (Phase II)

The excavation of SNOLAB is structured in two phases. Phase I which is presently under construction is the creation of the Rectangular Hall, Ladder Labs and the new personnel facilities. Phase II would add a second large experimental cavern called the Cryopit intended for large scale cryogenic experiments. Phase II is not presently funded.

Utility Area

	The Utility Area contains the chiller system to cool the laboratory, a waste handling facility and the emergency diesel generator. It is located old mine workings outside the clean room space of the laboratory.
	The "Chiller Drift" will contain a 320 Ton chiller system to cool the laboratory. The white bags are "shotcrete" the spray on concrete used to cover the excavation walls.

Existing SNO Facility

The SNO experiment ended data taking on 28 November 2006 and is now decommissioning. The 1000 tonnes of heavy water on loan from Atomic Energy of Canada is now being returned. After the detector is drained of heavy water, the cavity will be refilled with ultrapure light water. The next experiment expected to utilize the cavity is the SNO+ low energy solar neutrino and geo-neutrino experiment and conversion of the detector is expected to begin in 2008.

Surface Facility

	The SNOLAB Surface Facility. A 34,000 sq ft facility to provide support for experiments underground as well as office and meeting room space.
	The surface facility is equiped with several class 1000 clean room laboratories for prototyping and staging for experiments being deployed underground.
	Many of the radiological assays for ultra low background experiments require chemistry to enhance the detection of radioactive trace elements. A clean room chemistry laboratory in the surface facility provides support for the experiments.
	A Low background counting laboratory is used to measure minute quantities of radioactivity assayed from the SNO experiment.
	The surface facility has several meeting rooms including a 100 seat auditorium.