Cosmic Ray Observatories
University of Tasmania

The following tables and associated material are slowly being completed. For further information please contact John.Humble@utas.edu.au
Latest changes 12 March 2003


Neutron Monitors

Location

Design

Latitude

Longitude

Altitude

Vertical Cutoff Rigidity (GV)

Data Records

From

To

Brisbane
Australia

12 IGY

-27.50

152.92

~Sea-level

7.2

30 Nov
1960

31 Dec
1973

9 NM-64

-27.42

153.08

~Sea level

7.2

1 Jan
1977

June
1993

-27.42

153.12

~Sea level

7.2

1 July
1993

30 Jan
2000

Casey
Antarctica

12 IGY

-66.28

110.53

~Sea level

0.01

12 April 1969

31 Dec
1970

Darwin
Australia

9 NM-64

-12.42

130.87

~Sea level

14.0

1 Sept
1977

14 Oct 2000

Hobart
Tasmania

12 IGY

-42.90

147.33

15 m

1.88

1 March 1967

22 Nov
1977

18 m 1.88 1 Nov
1975
15 Nov 2001

9 NM-64

-42.90

147.33

18 m

1.88

1 April
1978

18 Nov 2001

Kingston* Tasmania

9 NM-64

-42.99 

  147.29

  65 m

  1.88

20 April 2000

Present

18 NM-64

21 Dec
2000

Present

Lae
New Guinea

3 IGY

-6.73

147.00

~Sea level

15.5

July
1957

28 Feb
1966 #

Mawson^
Antarctica

12 IGY

-67.60

62.88

~ 15 m

0.22

1 April 1957

11 Oct
1972

~ 30 m

1 Jan
1974

12 Feb 1986

6 NM-64

13 Feb
1986

17 Oct 2002

18-NM-64

17 Oct 2002

Present

Mt Wellington
Tasmania

12 IGY

-42.92

147.24

725 m

1.89

July
1956

31 Jan 1967

6 NM-64

-42.92

147.24

725 m

1.89

5 Jun
1970

11 Dec 2001

Transportable

3 NM-64

The Universities of Delaware and Tasmania are currently using this instrument for annual ship-borne latitude surveys between Seattle, USA and McMurdo, Antarctica.  Various routes are used.

Wilkes
Antarctica

12 IGY

-66.42

110.45

Sea level

0.01

5 Mar
1962

9 Apr
1969

* The Kingston instrument is owned and operated by the Australian Antarctic Division (AAD).
^ Ownership of the Mawson monitor was transferred from the University to the AAD during 2001.
# Operation continued beyond that date but data are uncertain. See note under station entry.

 

Underground muon telescopes

Station

Instruments

Latitude

Longitude

Vertical Depth Below Surface

Cambridge, Tasmania 12 m2 Proportional Counters      
Liapootah, Central Tasmania 20 m2 Scintillators      
Poatina, Northern Tasmania 8 m2 Proportional Counters      

Surface muon telescopes

Hobart. 9 m2 multi-directional scintillator telescope, operated jointly with Nagoya University .

 


Background
The following material gives brief details on the various neutron monitor installations that have existed in Tasmania.  More extensive material on the background to the studies and some details of other programs may be found in
50 Years of Cosmic Ray Research in Tasmania - ed Dr M L Duldig, ANARE Research Notes #102, 2000

Neutron Monitoring Program
The University of Tasmania has monitored the cosmic ray secondary neutron flux since July 1956, covering as wide a range of latitudes, and therefore cutoffs, as practicable from time to time. By 1999 it was clear that changes to University funding and staffing, plus several external events, had rendered impracticable the long-term continuation of this program. Accordingly the University of Tasmania equipment is being progressively handed over to the Australian Antarctic Division (AAD) to install a 'new' monitor at Kingston, Tasmania, a few kilometres south of the present Hobart monitor and to enlarge the present neutron monitor at Mawson. These two stations will receive updated electronics and will become part of the SpaceShip Earth program initiated by the University of Delaware.

Brief details of the changes at each station will be found under the station headings below.

Brisbane
The neutron flux was first monitored at Brisbane with an IGY type instrument installed in 1960 at The University of Queensland's research farm at Moggill, in Brisbane's south-western outskirts.

The replacement NM-64 neutron monitor at Brisbane was installed in January 1977 at a site adjacent to the Australian Bureau of Meteorology (BoM) observation station at the former Brisbane airport. The equipment came from the former Fort Churchill neutron monitor and was provided by the University of Texas at Dallas.  A new Brisbane Airport was opened in the early 1990s and the neutron monitor was moved to the BoM's site at the new airport in mid-1993.

By 1998 the BoM were indicating a further move. Shortage of funds and the impending rationalisation led to the eventual decision to close the Brisbane monitor shortly before the BoM withdrew from their site and to return the equipment to Tasmania. Accordingly the Brisbane neutron monitor was switched off permanently at 01:10 UT on 31 January 2000. The monitor was immediately dismantled and had left the site by 4 February. Its components were used to form the first half of the new Kingston monitor.

Casey
The former Wilkes monitor was installed in a new laboratory at the nearby Casey base in April 1969 after only three days out of use. Budgetary limitations forced its closure at the end of December the following year.  The components were subsequently returned to Australia.

Darwin
The first neutron monitoring at Darwin occurred in September 1977 with the installation of the second half of the former Fort Churchill instrument provided by the University of Texas at Dallas. As at Brisbane, the monitor was installed at a site adjacent to the BoM observation station at the airport. By the mid 1990s BoM were seeking a new off-airport site, the move eventually being delayed until late 2000.  As at Brisbane, shortage of funds and the impending rationalisation led to the decision to close the Darwin monitor shortly before the BoM left their site. Accordingly, the Darwin neutron monitor was switched off permanently at 21:00 UT on 14 October 2000. It was immediately dismantled and left the site on 18 October. Following refurbishment, its components were used to form the second half of the Kingston monitor.

Hobart
IGY type monitors operated on the Hobart campus of the University of Tasmania, effectively at sea-level, from the late 1960s to the closure of the observatory in mid-November 2001. Triggered by the loss of the Mt Wellington station in the February 1967 bush-fire, regular observations at the campus started in March 1967 in an old building at 15 m asl.  This 12-counter instrument remained in operation until 22 November 1977 although computerisation of data recorded by it ceased after 30 September 1973. At May 2000 it was not known if the later records are recoverable.  On 1 November 1975, a second 12-counter monitor was opened in a new observatory on the University campus at 18 m asl.. This instrument closed early on 16 November 2001 as the Hobart observatory was being decommissioned.

A 9-NM-64 IQSY monitor was installed in the new observatory in April 1978. It too was affected by the rationalisation. Closure was originally planned for some time in 2002 but logistic imperatives brought this forward to 00:10 UT on 19 November 2001.  Six of its detector tubes will go to Mawson in late 2002 as part of the enlargement of that instrument. 

Kingston
The first half of the AAD's NM-64 neutron monitor at Kingston was installed in April 2000, constructed from components returned from Brisbane. Test running with six counters commenced at 00:20 UT on 20 April. Full operation with all nine counters commenced on 28 April.  For the time being this section continues to use its original ex-Brisbane electronics and recording system.  Upgrading of electronics is planned for mid 2003.

The second half of the monitor commenced operations in December 2000 using the lead, polyethylene and detector tubes from the closed Darwin monitor fitted with new electronics and recording system.

Lae
A 6-counter IGY instrument was installed in July 1957. Logistic problems hindered adequate maintenance of the monitor, which operated in a highly adverse environment. For these reasons there are a number of significant gaps in the data-set. The monitor was eventually disassembled and returned to Hobart, apparently in 1970. All data were recorded on event recorder charts. Processed data were never computerised at the University of Tasmania and only paper records exist in Hobart, covering the period from commencement of recording to February 1966, when data processing appears to have ceased. Charts for the period from thence to May 1970 have been found but have not been read. It is not at present (October 2000) known if the chart set is complete.

Mawson
Neutron monitoring at Mawson started in March 1957 with the installation of a standard 12-counter IGY type instrument owned by the University of Tasmania and operated by the AAD. The instrument was replaced in 1986 by an NM-64 type monitor. A full six counter pile was installed but only three detector tubes were available for the first year of operation. The other three detectors were installed early in 1987. The monitor was enlarged to 18 counters in October 2002 and is now owned by the AAD and operated as part of the SpaceShip Earth network.

Mt Wellington
Mt Wellington is an approximately 1270 m mountain located immediately west of, and overlooking, the city of Hobart. An IGY type neutron monitor was installed on it in July 1956 at an altitude of 725 m.  The detector building was located behind a resort hotel known as "The Springs", at the highest point on the mountain at which electric power was then available. The hotel and monitor were both destroyed in a major bush-fire on 7 February 1967. The weekly visit to recover data had been due that day but was not possible because of the fire conditions. Consequently the last available data are for 31 January.

The 6-NM-64 replacement station was commissioned in June 1970 on the same site, funding problems having caused the lengthy delay. As part of the rationalisation process it was closed early on 12 December 2001, rather than the originally announced 'some time in 2002'.   The components were then despatched to Mawson as part of the enlargement of that monitor.

Wilkes
A standard 12-counter IGY type instrument, owned by the University of Tasmania and operated by the AAD, was installed at the Wilkes base in 1962 with the aim of observing closer to the geomagnetic pole than at Mawson.  By 1969 the buildings at Wilkes were in poor physical condition.  The entire station was closed and most equipment was moved to the nearby replacement station, Casey.   The neutron monitor was moved in April 1969.