line 25 & 65:
- we typically load our support structures with way less that what they could take. Strength is really not what we are after but rather stiffness.

line 55-56:
- twice ‚need to be‘ in sentence
- what is ‚a certain‘ operational temperature?
- what is a ‚large amount of heat‘?
- why is ‚low heat capacity‘ relevant? Would anything change if the sensors had a high heat capacity?

line 58:
- in line 55-56 you claim that large amount of heat is generated in the sensors, whereas here you claim that after irradiation ‚also‘ the sensor contributes to the heat generation.

line 61-63:
- add reference to paper on bi-phase CO2 cooling

line 67:
- ‚… OF the thermal properties…‘ 

line 93-94:
- ‚ply‘ and other CFRP buzz words need to be defined.

line 100:
- ‚highly thermally conductive carbon fibre composites‘ -> ‚ultra high modulus carbon fibre composites‘, because after all the fibre is sold as UHM and not high thermally conductive.

line 102:
- why ‚pre-preg‘ and ‚pre-impregnated‘ in quotes?

line 118:
- fig 1b doesn’t show how a sample is mounted between two copper bars.
- ‚sits‘ is a bit colloquial.

line 122:
- what is ‚high thermal conductivity‘?

line 123:
- what is ‚excellent‘ thermal contact? By the way in line 130 the thermal contact is only ‚good‘ although the same TIM is used.

line 128:
- the arrangement of plots is confusing. Given that Fig 2b show the common schematics, why not make this a stand-alone figure 1.

line 160:
- ‚tellurium copper‘ -> ‚tellurium copper CW118C‘

line 163-164:
- what exactly is meant by ‚equalize‘?

line 175-177:
- This sentence reads a bit strange and is hard to understand. How about: ‚…, the fraction of sample area A_S to flux-meter area A_F is between…’ This would then also define A_S and A_F

line 197-199:
- this is not understandable, please rephrase and elaborate
- ‚stable‘ with respect to what?
- What is done with the temperature readings in the 30 minute window (fig 3b)? What values go into the plot shown in fig 4 a&b?

line 202 / fig 4:
- why does the slope (heat flux) change when going from fig 4a to 4c and 4b to 4d?
- Actually, why do you need plots (c) and (d). The measured heat flux is given by the slope and for the extrapolation to obtain T_HF and T_CF only plots (a) and (b) are needed.
- You only briefly mention in the figure caption the standard deviation of the recorded temperatures. What about the error on the thermistor position. The thermistor has a certain size and my guess is that the holes in the flux meters are large enough to provide only a loose fit to the thermistor. Please elaborate on that error in the context of measured flux as well as extrapolated sample temperature at the interface.

line 206:
- ‚…, as shown in figures 4(a) and (b)‘. The extrapolation to both ends of the sample is not shown in the figure.

line 212-218:
- For every sample series a single R_int value is extracted from the fit to the R vs. l_S distribution, although every data point measured results from a different sample from the series being clamped into the measurement device. How valid is the assumption that R_int is constant for a given series of samples?

line 221:
- the exact type of copper and aluminium is only available after following the links in [12] and [13]. Please change ‚copper‘ to ‚copper CW004A‘ and ‚aluminium‘ to ‚aluminium AW-6061‘.

line 225-226:
- References [12] and [13] point to the web site of a distributor and not a manufacturer.
- for Al I never came across a manufacturer quoting a specific value for k instead of a range. For 6061 k is between 170-200W/m/K according to many data sheets available online.

line 226-228:
- ‚copper-TIM-sample‘ is confusing. Why not use ‚flux-meter-TIM-sample‘ instead?
- R_int could be measured directly by simply not placing a sample between the two flux-meters. Has this been measured and if so how does the measured value compare to the quoted values?

line 220-232:
- the title of this section is ‚Calibration measurements‘, but the results presented are rather validation measurements on reference samples. What is actually done in terms of calibration?

line 237 + line 267-269:
- what exactly is meant by ‚balanced‘? Looking at fig 4(a) and (b) and assuming that in this measurement the flux-meters were balanced, I guess that balancing means that the temperature at l_s/2 corresponds to roughly ambient temperature. If this is the case, there will always be heat transfer from the hot flux-meter to the ambient and a heat transfer from the ambient to the cold flux-meter. This means that the second term in 4.1 must never be zero. How do the values for this term compare to the first term?

line 241-242:
- It would be good if some reasoning for the value of the used film coefficient could be added.

line 243:
- ‚…for the FEA to measure…‘ -> ‚…for the FEA to estimate…‘

line 265:
- shouldn’t this be ‚Q_HF and Q_CF‘ instead?

line 233-280:
- More details on the FEAs and how the results are used in estimating the systematic uncertainties would be beneficial.