Tungsten medical shielding

Nuclear medical radiation shielding

Tungsten alloy is ideal for shielding against X rays and gamma radiation. The very high density of tungsten shielding (more than 60% denser than lead) allows a reduction in the physical size of shielding components, without compromising their rigidity or the effectiveness of the shielding characteristics.
Tungsten heavy alloy shielding is used in applications such as collimator, nuclear shielding, beam stop, PET syringe shield, vial shield, isotope container, FDG container, multi leaf collimator etc.

Positron emission tomography (PET)

Positron emission tomography (PET) is one of the nuclear medicine techniques available for diagnosis. Whilst X-rays provide information on the structure of the body, PET shows the chemical function of a particular organism. PET involves the injection of FDG (a glucose-based radionuclide) from a shielded syringe into the patient. As the FDG travels through the patient’s body it emits gamma radiation which is detected by a gamma camera, from which the chemical activity within cells and organs can be seen. Any abnormal chemical activity may be a sign that tumours are present.
PET scans are frequently used to detect cancerous tumours and diseases of the brain and coronary arteries.

Applications for tungsten alloy shielding in PET

PET syringe shield
Tungsten vial shield
Tungsten FDG transport container
Collimator for gamma camera
Technetium generator

Multi leaf collimator

Radiotherapy destroys cancer by directing beams of radiation directly onto the tumour. The beams of radiation require a very fine focus to avoid harming the surrounding healthy tissue. This focus is achieved by using a multi-leaf collimator, consisting of two rows of very thin tungsten alloy plates, which can be configured to exactly match the dimensions of the tumour.

Tungsten Alloy Data Sheet

Type	Density (g/cm³)	Tensile strength (MPa)	Elongation	Hardness (HRC)
85W-10.5Ni-4.5Fe	15.8-16.0	700-1000	20-33	20-30
90W-7Ni-3Fe	16.9-17.1	700-1000	20-33	24-32
90W-6Ni-4Fe	16.7-17.0	700-1000	20-33	24-32
91W-6Ni-3Fe	17.1-17.3	700-1000	15-28	25-30
92W-5Ni-3Fe	17.3-17.5	700-1000	18-28	25-30
92.5W-5Ni-2.5Fe	17.4-17.6	700-1000	25-30	25-30
93W-4Ni-3Fe	17.5-17.6	700-1000	15-25	26-30
93W-4.9Ni-2.1Fe	17.5-17.6	700-1000	15-25	26-30
93W-5Ni-2Fe	17.5-17.6	700-1000	15-25	26-30
95W-3Ni-2Fe	17.9-18.1	700-900	8-15	25-35
95W-3.5Ni-1.5Fe	17.9-18.1	700-900	8-15	25-35
96W-3Ni-1Fe	18.2-18.3	600-800	6-10	30-35
97W-2Ni-1Fe	18.4-18.5	600-800	8-14	30-35
98W-1Ni-1Fe	18.4-18.6	500-800	5-10	30-35
90W-6Ni-4Cu	17.0-17.2	600-800	4-8	25-35
93W-5Ni-2Cu	17.5-17.6	500-600	3-5	25-35