Table 1.

Studies implementing calorimeters for dosimetry of FLASH beams

Calorimeter type	Beam & energy	Average dose rate	Dose-per-pulse	Pulse duration	Uncertainty (k = 1)	Reference
Primary standard graphite calorimeter	250 MeV protons	Approx. 65 Gy/s	N/A	72.8 MHz RF repetition rate corresponding to 0.2 ns micro-pulses separated by 13.7 ns intervals	0.9 %	29,30
Transfer standard graphite calorimeter	200 MeV electrons	0.2–50 Gy/s	0.03–5.3 Gy/pulse	Approx. 100 ns	1.2% (no uncert. budget)	31,32
Small portable graphite calorimeter	15–40 MeV laser-driven protons	109 Gy/s (one ps pulse delivered)	1–3 Gy/pulse	Approx. ns	Not stated	33
Aluminium calorimeter a	50 MeV electrons	1–9 Gy/s	0.2–1.8 Gy/pulse	2.5 µs	0.5% (no uncert. budget)	31
Aerrow graphite calorimeter a	20 MeV electrons	3–28 Gy/s	0.6–5.6 Gy/pulse	2.5 µs	1.06 %	34,35
Al-core secondary standard calorimeter	6 MeV electrons	180 Gy/s	Approx. 0.45 Gy/s	4 µs	1.25%	32

^aThese studies used average dose rates below the threshold of the FLASH effect. ⁸