Report on the Workshop for

Report on the Workshop for

http://www.hep.umn.edu/lbcf/workshop/

Workshop Agenda

SNOLAB Workshop IV, 17 Aug 2005


● Identify cross disciplinary applications for low background counting.

● Identify areas for improving low bg counting to better fill the users’ needs.

● Quantify the low background counting capabilities of sites in North America.

● Develop a means of scheduling access to counting facilities for users.

Workshop Goals


● Particle/Astrophysics

● Semiconductor manufacture

● Biology

● Archeology

● Environmental Monitoring and Emergency Response

● Security

Counting Across Disciplines




● Biology

● Archeology


● Security


IC Materials Overview● High purity metals and alloys

– Cu, Al, Ta, W, Ti, Pb, Sn, Ag, Ru● Range in purity from 99.99% to

99.9999%● Alpha Activity Requirements

– 0.02 hr‑1cm‑2 : early 1990’s– 0.01 hr‑1cm‑2 : late 1990’s– 0.002 hr‑1cm‑2: 2001– 0.0002 hr‑1cm‑2:2006

● Primary alpha emitters– 210Pb in Pb/Sn solders– U & Th

Material purity critical to reliability

Low Alpha Material Specification

0.0001

0.001

0.01

0.1

1990 1995 2000 2005 2010

Year

cts/

hr/

cm2

Synergies WorkshopB.Clark

Current Instrumentation Capability● Industry uses Gas Proportional

Counters– Area :1000 cm2 – Geometry: 2– Background– 2-3 cph optimal, 4-6 nominal– No energy spectroscopy

capability● Limited ability to identify

contamination sources● 0.002 analysis requires ~7 days

counting time for 20% RSD

Current instrumentation incapable of timely analysis

Ordela 8600

Alpha Sciences 1950

Synergies WorkshopB.Clark

Bulk Memory Test at Tower-Soudan

Synergies WorkshopJ.Wilkinson

Bulk Memory Test at Tower-Soudan

Synergies WorkshopJ.Wilkinson




● Biology

● Archeology


● Security


Production Inventory Inventory

Nuclide half-life atom/m2/sec dpm/m2 at/cm2

10Be 1,500,000 years 460 27,000 3,070,000,000,000 26Al 710,000 years 1 84 4,520,000,000 36Cl 310,000 years 11 660 15,000,000,000 81Kr 230,000 years 0.01 1 12,400,000 14C 5,730 years 25,000 1,500,000 652,000,000,000 39Ar 268 years 129 7,750 158,000,000 32Si 150 years 2 96 1,090,000 3H 12.3 years 2,500 150,000 140,000,000 22Na 2.6 years 1 52 10,200 35S 87 days 14 840 15,200 7Be 53 days 810 48,600 535,000 37Ar 35 days 8 498 3,620 33P 25.3 days 7 408 2,140 32P 14.3 days 8 486 1,440

Synergies WorkshopE.Brown

H2PO4

H2PO4

DOPH2PO4

DOPPart. P H2PO4

DOPPart. P

H2PO4

DOPPart. P

33P/32P = 0.82 33P/32P

= 1.0533P/32P = 0.95

33P/32P = 1.15

33P/32P = 1.4

33P/32P ratios in dissolved and particulate P result from the source ratio (i.e. you are what you eat) and

the P residence time.Synergies WorkshopE.Brown

32P t½ =14.3 d33P t½ = 25 d

32P/ 33P t½ = 33.4 d

Advantages:•P is a nutrient used by all living organisms.•Radioisotope half-lives relevant to biological timescales.•In-situ tracers avoid issues associated with ‘bottle effects.’•Ratio of isotopes minimizes changes due to dilution.

Disadvantages:Large sample volumes and extensive purification:

5 tons per sample!!! Several hour shiptime.

32P, 33P formed by spallation reactions in the atmosphere

Synergies WorkshopE.Brown




● Biology

● Archeology


● Security


Public Health Laboratory:Operations

● 1. environmental monitoring outside nuclear reactor sites

● 2. safe drinking water; monitor public water supplies

● 3. radiological emergency response

Synergies WorkshopJ.Brenner/J.Lorenz

Sample Collection per Facility

● River water samples – Upstream 1/month until freeze over– Downstream 1/month

River sediment 1/yr● Milk from local dairy farm 1/month● Cattle feed 1/month● Hay and grasses 1/month during growing season● Apples 1/month during growing season● Air filter samples 2/month● One residential well sample 1/month


Methods of Analysis● Tritium

– Analysis based on EPA Method 906● Instrumentation

– Packard TRICARB-2750 Liquid scintillation counter MDH Laboratory MDC <200 pCi/L Drinking Water MCL 20,000 pCi/L Drinking Water required activity 1,000 pCi/L 46 river water samples per year (average)



● Standard analysis techniques and off the shelf counters

– Well defined procedures

● Modest shielding

– E.g. Pb castles in basements.

● Sensitivity is probably ok.

● Major issues are throughput and speed.

Public Health

Radiation Laboratory Analysis

0

50

100

150

200

250

300

350

400

Jan

03'

Apr

03'

Jul

03'

Oct

03'

Jan

04'

Total Samples

Drinking Water

Program



● Whole Body Counting - Tom Shutt

● Beta Cage - Richard Schnee

Techniques

Water shield

SS Sphere6-8 m Ø(less with low background PMTs)

scintillator

PMTs≈ 100

Sample20 cm Ø, 40 cm longPlastic - 13 Kg plasticCu - 110 Kg

• “Mini-me” version of Borexino

• Whole-body counting of sample

• 14C sets threshold near 250 KeV

A new facilityLaura Cadonati (MIT)

Synergies WorkshopT.Shutt

Synergies WorkshopR.Schnee


● Europe

– ILLIAS

● North America

– Berkeley

– Kimbalton

– PNNL and LoMo

– SNOLAB

– Soudan

Counting Facilities

Synergies WorkshopK.Heegar for K.Lesko

Counting Facilities: Berkeley

Mine Portal

Sedimentary Host Rock

Synergies WorkshopB.Vogelaar

Counting Facilities: Kimbalton

Drive-in Access: Width 42’ (12.8 meters) Height 26’ – 105’ (8 – 32 meters) Length up to one mile



Base facility:

•1700 ft deep• accessed by truck (or bus)• concrete pad of 42'x113’Concrete poured July 19, 2005; ready Sept 2005

PLAN:• water, septic, 50kW electric• internet• 20'x40' assembly hall• 12'x40' office trailer• 8'x24' NRL lab• unallocated (~ 40'x40')• 30 minutes from VT to the mine• 15 minutes from the surface



Material Screening

HPGe detctors, like these at Gran Sasso

Prefabricated laboratories can be driven in.



Synergies WorkshopT.Hossback

Counting Facilities: LoMo


Counting Facilities: LoMo


Counting Facilities: WIPP


Counting Facilities: WIPP

Low background Screening and Prototyping Facility

at the Soudan Underground Lab

40’ x 35’ x 100’ cavern surrounded by a 99% efficient active muon veto

SOLO HPGeJim Reeves: Cu Electroforming SBIR + Cu screening detector (microBq/kg)

Diode M (35%)Twin (75%)UF detector (100%)

Synergies WorkshopP.Cushman

Counting Facilities: Soudan

Low background Screening and Prototyping Facility

at the Soudan Underground Lab

CDMS offices

CDMS Aux Clean RoomBFand SiLi detector

Veto shield repaired last summer DAQ: location & time stamp for each muon Synergies

WorkshopP.Cushman


Ante-room Ante-room

Multi-purpose clean room

Clean room over tank

Water ports with crane

Electro form

40 ft

Upper mezzanine above tank top

Use

r sh

ield

ing

Clean room over tank

anteroomClean room

Clean room

Water tankShieldedbays

mezzanine

anteroom

radon scrubbing plenum.

stairs

current mezzanine

Muon veto shield

Muon veto shield

Mu

on

vet

o s

hie

ld

Mu

on

veto sh

ield

100 ft

Drawings and Design Consultation: Short Elliott Henderson Engineering, Inc

Synergies WorkshopP.Cushman



● Location– http://www.hep.umn.edu/lbcf/integration/index.html

● Intended to be an access site to the low background counting facilities (primarily in North America).

● Will list the capabilities of the facilities

● Eventually allow scheduling of samples.

● Contact

– P. Cushman: [email protected]

Integration Website


● Particle Physics Experiments want

– Counting Speed

– Increased Sensitivity

● Other disciplines want

– Mostly Counting Speed

– But also in some cases increased Sensitivity

● Various plans to expand the underground screening facilities (Soudan, Kimbalton)

● Effort to develop an integrated low background counting infrastructure (Integration Website).

● However, presently there does not appear to be excess capacity in North America.

Summary

End

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