Radiation Safety. Amplified.
Join us on Linkedin
Follow us on YouTube
Subscribe to our Blog

Châteaux de plomb, blindages et accessoires

Produits dans cette famille

CosmicGuard™ – Système Anti-Cosmiques de réduction du bruit de fond

CosmicGuard™ – Système Anti-Cosmiques de réduction du bruit de fond

Description

CosmicGuard est un module pouvant être installé sur tout système de spectrométrie gamma comprenant un détecteur HPGe (Germanium hyper pur), un analyseur multicanal numérique Lynx et un logiciel Genie 2000 ou Apex-Gamma. Ce système totalement autonome, composé d’un détecteur de garde et de son électronique intégrée se monte soit directement sur le blindage avec un couvercle circulaire de 50.8 ou 55.9 cm de diamètre, soit au moyen d’un mécanisme de levage se fixant sur la table support du blindage pour les versions à ouverture par le haut. Le système se connecte directement à l’analyseur numérique Lynx du détecteur HPGe et à un ordinateur de contrôle avec Genie 2000 ou Apex® – Aucun module NIM ou autre dispositif électronique n’est nécessaire.

Pourquoi la réduction du bruit de fond cosmique est-elle importante ?

Pour les systèmes de spectroscométrie gamma, le bruit de fond provient principalement de trois sources: radiations telluriques, radiations internes et radiations cosmiques. Les radiations terrestres naturelles proviennent de l’uranium, du thorium et de leurs descendants, ainsi que du potassium 40. Elles sont en grande partie réduites en positionnant le détecteur HPGe à l’intérieur d’un blindage en plomb.

Les radiations internes peuvent provenir des matériaux composant le détecteur HPGe, le blindage ou de l’échantillon lui-même en raison d’une déposition partielle de l’énergie dans le détecteur (diffusion). Dans de nombreux systèmes de comptage, la composante de diffusion sera présente, bien que des solutions de suppression (anti-Compton) puissent être appliquées dans certains cas pour réduire ce type de bruit de fond. Les détecteurs CANBERRA™ sont conçus à l’aide de matériaux sélectionnés afin de minimiser la contribution du détecteur. Pour réduire ces radiations liées au détecteur, CANBERRA offre des options de cryostats permettant de déporter le préamplificateur à l’extérieur du blindage (Remote Detector Chamber – RDC), ou encore l’utilisation de matériaux sélectionnés ultra bas bruit de fond ULB (Ultra-Low Background).

Features

  • Réduction notable du bruit de fond cosmique ne pouvant être obtenue avec uniquement un blindage en plomb
  • Réduction typique du bruit de fond de 15% à 40%, permettant d’abaisser les limites de détection et/ou les temps de compSolution clé en main pouvant être implémentée sur des configurations de blindage/ détecteur HPGe nouvelles ou existantes
  • Compatible avec la plupart des blindages standards pour détecteurs HPGe à ouverture frontale ou latérale
  • Electronique intégrée dans le module CosmicGuard. Aucun module NIM ou autres ne sont plus nécessaires
  • Connexion par un câble unique au PC d’acquisition ou au réseau du laboratoire
  • Réglages à l’aide d’une interface utilisateur simple et intuitive
  • Nécessite l’Analyseur Multicanal Numérique Lynx® connecté au détecteur HPGe, et le logiciel Genie

CosmicGuard™ – Cosmic Veto Background Reduction System

Model 767 Front Opening Split-Top Shield

Model 767 Front Opening Split-Top Shield

Description

The 767 is a full-size and full-featured lead shield for use with germanium detectors having a vertical orientation. It has several unique design features and is built with a great deal of attention to fit and finish. The 767 features 10 cm (4 in.) lead thickness and is jacketed by a 9.5 mm (3/8 in.) steel outer housing. The graded liner consists of a tin layer of 1 mm (0.040 in.) thickness and a copper layer of 1.5 mm (0.062 in.) thickness. There is no exposed lead in the 767 with or without the doors closed. The inside dimensions are 28 cm (11 in.) diameter by 40.6 cm (16 in.) high.

The top doors of the 767 are linked so they open and close together regardless of which is actuated. The front door opens to the right on precision adjustable hinges and provides full shield access.

Top doors are linked - so they open and close together - Front door provides full-area access

A novel latch secures both the front and top doors and provides a means to lock the shield with a user-supplied padlock.

The shield table is equipped with leveling legs and with braces which allow the assembled shield to be moved with a simple pallet truck.

The 767 is finished outside with an attractive textured light gray epoxy paint. The copper interior has a brush grain finish with a clear polyurethane coating to retard tarnishing.

Features

  • Four-inch low background lead
  • Graded tin and copper liner
  • Fully clad - no exposed lead
  • Full area front door
  • Synchronized split top door
  • Lockable door latch
  • Textured epoxy finish

Model 767 Front Opening Split-Top Shield

Model 747 and 747E Lead Shield

Model 747 and 747E Lead Shield

Description

The Model 747 CANBERRA Lead Shield is intended for use with Germanium detectors. It will prevent high background counts due to external sources, thus reducing counting times and improving the lower limit of detection. This shield is compact and easy to use with only 0.4 m2 (4 ft2) of floor space required. The shield may be set up so that the door opens right or left without need for clearance to the rear. A convenient lever-actuated door lift allows the door to be placed firmly on the shield to prevent direct path radiation from entering.

The 1 mm (0.040 in.) tin and 1.6 mm (0.062 in.) copper graded liner prevents interference by lead x rays. The exterior is attractively finished with light grey textured paint, the interior is coated with clear polyurethane to prevent oxidation and facilitate cleaning. The floor of the shield has a 12.1 cm (4.75 in.) diameter hole which will accommodate either flanged or slimline cryostats.

The 747E model is 10 cm (4 in.) shorter than the standard 747 and does not have a door lift mechanism.

A number of options are available.Four-inch long, clamp-on cold finger extensions are available for most cryostats. Preamp hardware Option PHW (for CANBERRA Preamp) is also required to ensure that flanged cryostats fit within the 28 cm (11 in.) shield diameter. Adjustable foot pads provide a convenient means for leveling. Optional annular lead plugs are available to minimize the streaming path through the hole in the shield floor. A detector lift and taller table are available to accommodate installation of other cryostat types, such as the Cryo-Pulse® 5 Plus, MAC's and 7500SL-RDC. See option list on back for details.

Features

  • 4-inch thick low-background lead
  • Easy-to-use lever-actuated door
  • Compact – 2 foot by 2 foot floor space
  • Graded tin and copper liner
  • Adjustable foot pads

Model 747 and 747E Lead Shield

Model 777 Ultra Low-Background Shield

Model 777 Ultra Low-Background Shield

Description

The CANBERRA 777 is an ultra low-background lead shield for germanium gamma-ray detectors. It features 50% greater lead thickness than that of typical lead shields and is constructed from materials carefully selected for low background. The 777 is available in three versions which complement CANBERRA ultra low-background cryostats. The 777 (pictured right) can accommodate either a vertical dipstick slimline cryostat or a U-style cryostat. The 777A accommodates vertical dipstick cryostats only such as the 7500SL with a remote detector chamber (Model RDC-6). The 777B accommodates only U-style cryostats. All versions of the 777 are equipped with a swing-top door for sample chamber access and a door lift mechanism which allows the door to fit tightly against the shield body.

Background radiation from lead is dominated by 210Pb because other elements are chemically separated fairly effectively in the refining process. 210Pb decays with the emission of a 46.5 keV gamma ray. This gamma ray is generally absorbed by the tin-copper liner and may be below the energy range of the detector so it is of little concern. The 210Bi daughter of 210Pb, however, is of concern. It is an energetic beta emitter and bremsstrahlung from this beta gives rise to a continuum of background counts ranging up to 500 keV. For this reason, the 777 is constructed with layered bulk lead. The outer five inches is ordinary low-background lead while the innermost one inch is selected for 210Pb content of about 20 Bq/kg. This thickness of lead will stop the bremsstrahlung from the outer lead volume.

The 777 has a graded liner to stop the lead K-shell x rays in the energy range of 75-85 keV. Liner materials are low background tin with a thickness of 1 mm (0.040 in.) and high purity copper with a thickness of 1.5 mm (0.060 in.).

The 777 is equipped with a gas port for the introduction of gas (bottled air or nitrogen) to flush the shield interior and reduce background from radon and radon daughters. Boil-off nitrogen from the LN2 cryostat is a free source of gas but care must be taken to prevent liquid nitrogen from entering the shield and freezing the cryostat seals. An N2 purge kit is available from CANBERRA for most cryostat types.

The 777A (see illustration in PDF) is supplied with a table which supports the shield above the LN2 Dewar. This shield has an opening in the floor and a split annular back shield which surrounds the cryostat RDC neck. The 777B (see illustration in PDF) is attached to a steel plate which normally sits on the floor. The 777B has a side port which accommodates the horizontal arm of a U-style cryostat and a rectangular plug which is withdrawn vertically to provide access to the port. An optional cryostat stand (Model 777-5) is available to support the cryostat.

Features

  • 15 cm (6 in.) lead thickness
  • Ultra low-background materials
  • Versions for vertical or U-style cryostats
  • Purge port for radon expulsion
  • Graded tin-copper liner

 

Model 777 Ultra Low-Background Shield

Model 737 Lead Shield

Model 737 Lead Shield

Description

The Model 737 Lead Shield is designed to accommodate U-style cryostats which have a vertical detector chamber located at the end of a horizontal arm extending from the side of the Dewar. This detector/shield arrangement excludes the preamplifier and other hardware from the shield volume and eliminates all line-of-sight streaming paths to the detector element. These factors can contribute significantly to overall background reduction in the counting system.

Unlike most shields of this type, the 737 is designed for ease of detector installation with a narrow, stepped plug providing access for the horizontal arm of the detector. This plug is removed vertically, thus minimal space is required between the shield and the Dewar with attendant reduction in floor space required for the system.

Like the Model 747 Shield, the 737 has a graded copper-tin liner and is jacketed by 3/8 in. steel finished in an attractive light grey textured paint which matches other CANBERRA products. The exclusive CANBERRA door lift mechanism allows the shield door to close lightly against the shield body, reducing the streaming path to virtually nothing.

Lead Shield Model 737 - U-Style

Features

  • "No stream" design for U-style cryostat
  • Low center of gravity
  • Four-inch low background lead
  • Graded tin and copper liner
  • Easy detector installation
Lead Shield Model 707/707M - Slimline

Lead Shield Model 707/707M - Slimline

Model 707 Lead Shield

  • Economical and light weight
  • For Slimline cryostats
  • Construction: steel jacket, lead bulk, Sn/Cu liner
  • Dimensions:
  • 152 mm (6 in.) inside diameter
  • 254 mm (10 in.) inside depth
  • 51 mm (2 in.) lead thickness
  • Table included: 61 x 61 cm (24 x 24 in.) x 68-76 cm (27-30 in.) high
  • Shipping weight - 250 kg (550 lb)

Model 707 Lead Shield

Model 707M Modular Lead Shield

  • Modular construction
  • Maximum component weight- 227 kg (500 lb)
  • For Slimline cryostats
  • Construction: steel jacket, chevron lead rings, Sn/Cu liner
  • Dimensions:
  • 152 mm (6 in.) inside diameter
  • 254 mm (10 in.) inside depth
  • 102 mm (4 in.) shield thickness
  • Table included: 61 x 61 cm (24 x 24 in.) x 68-76 cm (27-30 in.) high
  • Shipping weight - 646 kg (1425 lb)

Model 707M Modular Lead Shield

Ge Detector Accessories

Ge Detector Accessories

Model 7413, 7413F Detector Tripod

  • For field measurements
  • Heavy duty construction
  • 7413 accommodates Slimline, MAC or Big MAC
  • 7413F accommodates Flanged, MAC or Big MAC
  • Detector element elevation (<30 cm to >120 cm)
  • Built-in level
  • Shipping weight - 9 kg (20 lb)

Model 757 Tungsten Shield/Collimator

  • High density (17 g/cc)
  • Compact
  • Requires special MAC
  • Specify collimator opening
  • Dimensions: 7.7 cm I.D. x 17.8 cm O.D. x 20.3 cm long (3.05 x 7.0 x 8.0 in.)
  • Shipping weight - 85 kg (187 lb)

Model 7415 Detector Lift

  • Accomodates MAC, Big MAC and Cryolectric II
  • Compatible with CANBERRA shields
  • Convenient and safe operation

Model 717 Portable Detector Shield

  • For MAC or Big MAC
  • 89 mm I.D. x 165 mm long (3.5 x 6.5 in.)
  • 25 mm (1.0 in.) thick lead
  • Brass lined-steel jacketed
  • Shipping weight - 34.5 kg (76 lb)

Model 7411 Detector Submarine

  • Accommodates single-port MAC
  • 6 m (20 ft) umbilical hose (longer available)
  • Ballast for fresh or salt water (specify)
  • Body Dimensions - 178 mm diameter x 591 mm long (7 x 23.25 in.)
  • Shipping weight - 20 kg (45 lb)

Model 7412 Annealing Kit

  • Fix radiation damage in situ
  • Includes:
  • Valve operator
  • Temperature controller (115 V ac only)
  • Heating tape or air heater (MAC)
  • Specify cryostat type
  • Shipping weight - 5 kg (11 lb)

Note: Controller subject to change with availability