System Performance Paper Draft 5¶

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This version is available for initial collaboration review. Deadline for reviews will be end of play Wednesday 14th April. Target journal is J. Inst. (Muons edition)

Comments received (in progress):¶

Mark Tucker ✓¶

I have not checked actual values, and I am commenting on the presentation in the paper.

I have some comments on section 7 of this paper. Grammatically:

1)Line 350: characterisation … was (not were) OK

2)Line 411, lose not loose OK

1)Line 423: of the of the repeated OK

And there is confusion caused by using bar. Typically, this is used to state a pressure above atmospheric pressure, i.e. 1.5 bar means a true pressure of 2.5 x atmospheric pressure; “bar” meaning “except atmospheric pressure” (c.f. bar none), unless specifiying “bar abs” which could be considered essentially self-contradictory. It is better to state all pressures in mbar to avoid confusion (except relief valve settings):

1)Line 366: 1150 mbar OK

2)Line 367: 1085 mbar Ok

3)Line 380: 1085 mbar OK

4)Line 384: 1505 mbar OK

5)Line 391: 1085 mbar OK

6)Line 402: The vessel was designed to withstand at least 2500mbar internally, the internal pressure was limited by the 1.5 bar (small b) relief valve to atmosphere, whilst the vessel was surrounded by vacuum.
OK

Lines 367-371: This is confusing as the period of data-taking is glossed over, and a description of venting (cryocooler off, heater on) is given priority as though this happened almost straight away after filling. You could change the text to: “The vessel then remained in this steady state during the period of data-taking, after which the vessel was vented. For the venting process, …”
OK

---

Rachel Gamet ✓¶

In the introduction we say MICE ran from 2008 to 2018 and, on P4 we say Fig 3 shows data taken in 2018. If my memory serves me correctly the final data-taking for MICE was in December 2017.
Correct. Was a typo probably coming from the fact was data reconstructed in 2018.

Fig 10 says it shows data at 400MeV/c, while in the text it says it is at 300MeV/c.
Is 300 MeV/c

On P10 we use the acronym SAPMT which I don't think has been defined, although earlier we do talk about single-anode PMT, which is what I assume it stands for.
Acronym added when defined

P18, line 373 would read better if changed to "The magnetic-field dependent temperature error, DeltaT/T, at 2.5T is 0.04%,....".
And line 376 should say "used" rather than "using".
OK

---

Maurizio Bonesini¶

I think the description of the Liquid Hydrogen Absorber
(section 7) is not pertinent. It clashes heavily with the abstract, where
we say that the paper `` documents the performance of the detectors used
in MICE to measure the muon-beam parameters''. I would skip it or at least
put in a separate appendix, explaining why it is described. A referee may
argue why we do not discuss other pieces of the cooling channel, such as
the diffuser, ... at this point.
Included the LH2 in the abstract. With respect to the solid LiH, the LH2 is an instrumented apparatus which deserves this discussion, in particular as a source of reference for the other analysis on LH2 data. The diffuser is discussed elsewhere.

In addition a relevant missing point is how the various efficiency on
electron ID, muon MIS ID ... translates into a systematic error for the
emittance measurement. At least as a guess.
The PID is analysis and beam (muoninc/pionic) dependent. For example comparing JN's scattering analysis and any other emittance one.
The pion contamination is compatible with what was aimed in the proposal (MICE note 21) which was 1/1000.

Minor comments:

line 35: I would add in figure 1 the acronyms TKU,TKD,SSU,SSD, FC ...
quoted in the text, eg
Spectrometer Solenoid > Spectrometer solenoid ....
(SSU)
to let the reader understand where they are.
OK

line 58: The bars of TOF0 ...> The bars of TOF0 were made of
BC-404 (BC420) scintillators.
OK

line 62: The TOF detector > one TOF detector
OK

line 45-110 I would be helpful to add a picture showing the stability of the
TOF system over data-taking. I remind a similar plot quoted in
reference JINST 7(2012) P05009 (figure 18)
We have decided time ago to do not include this plot.
The plot you quote was just one month of data taking. Over years of runs the calibration procedure has been constantly improved and the resolution depends on the spread of the beam used. For example external pixels have a larger residual bias in slab Dt. So showing different beams over the whole detector would produce artificial variations. Viktor confirmed this back in 2019 when was discussed the first time.

line 115: I would quote the type of PMT used
They were mentioned in former drafts and have been moved out following reviewers suggestions; as for the other detectors they are present in cited papers, where there are more details in terms of hardware.

line 126-133: I would report only for PID performances results obtained in
the MICE muon beam (as done for TOF: fig 4, for KL fig 8,9,
for EMR fig 12 and trackers fig 14) otherwise I would drop this
paragraph.
Muon beam above 200 MeV/c were used, up to the calibration beams at 400 MeV/c.

line 150: figure 8 and 9 show the same results twice, in different
formats. To avoid unnecessary duplication, I will show only figure
9, skipping figure 8.
OK

line 146: I would quote the PMT type used
As before.

line 180: I would specify the type of SAPMT and MAPMT used in EMR
As before.

Figure 11: -wording on the left panel is barely visible.
OK

In addition I would
try to use a figure showing how the readout is implemented
(similar to what is done in figure 7)
Removed the read out from Fig.7. Full read out too complex to be included in a schematic (while present in referenced documents).

line 209: the acronym SAMPT is never defined
OK

lines 230 310: as a general remark the description of the tracker is much
longer as respect to the other detectors. I would
trim it, avoiding details on spacepoint efficiency, noise, ...
stressing only track efficiency and track fit performance
The Tracker reconstruction itself is more complex than for the other detectors. In terms of line numbers is just 9 lines longer (14%) than the TOF section and in general well balanced between the sections.

Figure 13: I would either replace the image with a layout of one tracker
showing the different elements (as done in figure 7 for KL) or
add this layout to the shown image (side by side)
Removed the read out from Fig.7. Full read out too complex to be included in a schematic (while present in referenced documents, e.g. R.Asfandiyarov et al.,).

Section 7: see comments before.
As before.

Conclusions: Table 4 sounds odd to me. How track efficiency may be
considered PID ? Maybe its contents may be re-phrased in some
sentences. I think here some considerations on the influence of
PID efficiency, muon MIS ID ... on the systematic error on
evaluation of emittances must be put.
Removed the Track finding efficiency (already included in the Tracking section) from the table.

I think the paper is useful for other MICE papers, but it needs some
further refinements

---

Chris Booth¶

Line 22 ";" should be a comma.
OK

27 Specify "a kinetic energy of 800 MeV"? (We normally quote total energies.)
OK

33 I don't think there should be a hyphen in lithium hydride.
I agree, removed. PubChem doesn't show it either as a synonym.

47 delete "and" after "while".
OK

93 "Two slab signals".
OK

107 Clumsy sentence. "of the measured ToF distribution". Or just delete first "of"?
OK

153-4 Repetition of statement about zero field.
OK

157 Comma after "300 MeV/c".
OK

168 Delete "for" after "allowed".
OK

169 "Each plane", rather than "one plane".
OK

171 "could" rather than "would.
OK

Fig 11 Orientation is unclear. Would it be useful to add axes? Also red text is not very clear on dark grey.
OK. Added beam direction

207 Reorder sentence. Put "The mode ..." first? (It could be read that the later parts of the sentence refer to the 3.26% of cases.)
OK

<Line numbers screwed up!> In "based on these distinct characteristics", it is not clear what "these" refers to.
OK

Would it be useful to show specimen distribution of rho_p and chi-squared for both mu and e?
They were present in former drafts, but moved out in more recent versions.

243 Is the tracker in figure 13 really "on the bed of the coordinate measuring machine"?
Yes it is. Ken confirms

245 Comma should be semicolon, or new sentence.
OK

Figures 15 & 16: Captions are not very informative!
OK

Figures 15 & 16: Scales on ordinates don't look optimal.
Reducing the Y scale would magnify the marginal non-linear trends of the histogram.

Figure 17 Consistence of algorithm or consistency of constants/results?
OK, "results"

361 and following: I couldn't understand the relationship of the 0.1 K resolution (mentioned also on line 383) to the accuracy and stability of 9 and 12 mK (etc).
The correction factors have to rely on the the 0.1K resolution of the readout.

376 Delete "that" after "devised".
"...was devised that used..."

403 Comma should be semicolon, or new sentence.
OK

References: Capitalisation does not seem very consistent between different references!
OK

463 [8] "mK" (capital K).
OK

501 [25] Should "Jim" be here?!
OK

517 [32] Journal abbreviation and capitalisation inconsistent with others. (Also "Feb" not "FEB"?)
OK

524 [36] "MICE" (capitals).
OK

---

Henry Nebrensky¶

1) I agree that at first sight this paper looks a bit strange with the
LH2 stuffed in with the detectors; but I don't know if a separate
absorber-only paper would be accepted and this all needs publishing at
some point.
Included the LH2 in the abstract. The LH2 is an instrumented apparatus which deserves this discussion, in particular as a source of reference for the other analysis on LH2 data.

My thought was instead to present this paper as demonstrating the
basis of our claim that we correctly measure single particles, such
that it can be cited by the beam physics papers. That is, we would
like to write something along the lines of "MICE measured the passage
of single muons through the apparatus¹ which we here aggregate into
a series of synthetic beams... "
Making that claim requires that we

• know we have a muon (does the PID ID?)
• know its trajectory entering/leaving some stuff (does the Tracker Track?)
• know what the stuff is (else the exercise is pointless!)

I think this paper could (in combination with previous ones) justify
that claim without significant rework of the science payload, but it
will need rewriting the Intro/Summary sections.
I don't know how clear that is and it's very late here; basically it's
about justifying "MICE measured the passage of single muons..." vs
merely "MICE recorded some sets of space-point hits..."
The comment about the particle ensemble which we call "a beam" has been included. Is convenient to define a beam delivered into the detectors, but we measure single particles (opposite of other analysis where we assemble a beam, which is the ultimate object of the study).
I think the other points are addressed by the paper. A fully comprehensive PID is of course beam and analysis dependent, but single detectors do identify muons and discriminate between them and pions/electrons, up to EMR level.
As noticed during the internal review of the draft, the whole apparatus does the job it was designed for in the initial proposal, which is what we want to claim at this stage. All the other analysis use it for the specific measurements.

2) I understand the temptation to list the PMTs and electronics used
by the various detectors, but the result is hardly fun to read. Is
there a way to instead present this in a single table covering all
detectors?
Technical information for all the detectors is present in other papers.
A comprehensive list of details would mean scintillators, PMTs, cables, DAQ electronics, et cetera.

===

Title
"Performance of the MICE diagnostic system" A "diagnostic system" is
something that tells you why MICE doesn't work. "detector and absorber
systems"? (but see above)
This is not necessary true. A diagnosis would not just be used to spot a problem, but to characterize.

Abstract
line 12: mention LH2: "This paper documents the performance of the
detectors used in MICE to measure the muon-beam parameters, and the
physical properties at run-time of the liquid-hydrogen absorber."
OK

1 Intro
line 18: The timeS taken... (to match "... are long")
OK

line 21: "Ionization cooling..." the semicolon in that sentence is
wrong; use a pair of commas (one after [12, 13] and one instead of the
semicolon) instead. Either remove those around "where it loses energy"
or replace them with a pair of dashes.
OK

line 26: "MICE operated on the ISIS neutron and muon source..." to
"MICE operated at the ISIS neutron and muon source..." and "ISIS
accelerates protons..." to "The ISIS synchrotron accelerates
protons..." to make it clear we're not connected with the TS1 muon
beamlines
OK

line 29: delete "conventional"? (DS is superconducting)
OK.

line 31: "of two dipole magnets" to "of the two dipole magnets D1 and D2"
OK

line 33: remove hyphens from "liquid-hydrogen", "lithium-hydride" and
"focus-coil" (to match fig. 1).
OK

line 39: "and to quantify the properties..." to "and quantifies the
physical properties..."
OK

line 43: "The instrumentation of the liquid-hydrogen absorber is
discussed in section 7." to "The properties of the the liquid hydrogen
absorber are described in section7."
OK

fig.1 caption: remove hyphen from "liquid-hydrogen"
OK

2 TOFs
line 47: "while and" to "while"
OK

line 48-50 "The range of particle momentum..." This sentence is a
repeat of one in the introduction - is there a way to smarten this up?
Removed.

fig. 2: is there a way to indicate the beam direction?
OK. Added an arrow

line 100: can we change 'T' to 't' to avoid confusion with temperature in s7?
OK. Also in fig.3

line 103: we did run various Cooling Channel and Beamline components
in 2018, but never took any data.
OK

3 Cherenkov
fig. 5: is it possible to indicate the beam direction on this?
OK

line 131: move the definition of gamma to here
OK

4 KL
fig. 7: is it possible to add an arrow indicating the beam direction?
OK

line 160: "was been" to "has been"
OK

line 162: is "400 MeV/c" a typo? Other text and figure caption only
mention 300MeV/c
OK. It is.

5 EMR
line 168: "apparatus" to "Cooling Channel" Possibly delete sentence as
it's repeated near-verbatim at line 184.
OK deleted.

fig. 11: is it possible to indicate the beam direction, e.g. an arrow
labelled "beam" running down the central gutter? The usual
expectation is left to right, but the figures here are all either
subtly or very different!
OK.

7 Liquid-Hydrogen Absorber
line 349: remove hyphen from "liquid-hydrogen" throughout
OK

line 357: "the two domes of the thin aluminium end windows..." to "the
two domes of the end windows..."
OK

fig. 18 caption: "absorber/focus-coil (AFC) module" to "focus coil
module (FC)" for consistency with Intro
OK

line 361: "The temperature of the vessel was recorded by eight
LakeShore Cernox 1050 SD sensors with a resolution of 0.1 K." to "The
temperature of the vessel was recorded by eight LakeShore Cernox 1050
SD sensors at a resolution of 0.1 K." or even "The temperature of the
vessel was measured by eight LakeShore Cernox 1050 SD sensors recorded
at a resolution of 0.1 K" - the resolution refers to the recording of
the data values, not the sensors.
OK

line 367: remove hyphen from "steady-state"
OK

line 368: "...until the venting process began." to "... until the
venting process was begun 21 days later." for context regarding the
8-day fill (line 366).
OK. Similar comment from MT

line 369: "power of 50 Watt" to either "50 W" (better) or "50 Watts"
OK. 50 W

line 373: "temperature error at 2.5 T is 0.04%, ∆T/T," to "temperature
error , ∆T/T, at 2.5 T is 0.04%"
and italicise the T-for-temperature to distinguish it from Tesla and be consistent with line 393
OK

Note that [37] just seems to be pages 32-35 of [38] -
it may be better to only refer to [38] but give the specific page
number where relevant.
Correct, removed the first citation.

line 376: "that using" to "based on"
OK. Similar comments.

line 383: "The temperature scaling and magnet-current correction
factors also have an associated uncertainty as they are based on the
0.1 K resolution of the sensors." "...as they are based on the 0.1 K
resolution of the sensors." to "...as they are chosen/derived/selected
based on the 0.1 K resolution/granularity of the stored values." -
the resolution refers to the recording, not the sensors.
OK

line 389: "In the steady state condition.." to "While in the steady
state condition the liquid hydrogen was close to the boiling
temperature of liquid parahydrogen [39] (density 70.53 kg/m^3): the
average temperature of the eight sensors was (20.51 ± 0.07) K at
1.085 Bar (figure 19) allowing us to determine the uncertainty in the
density over this period as 0.08 kg/m^3 ."
OK

line 392ish: "which resulted in the contraction of the vessel." to
"contracting the vessel."
OK

eq. 4 - italicise the T to be consistent with text
OK

line 403: "The pressure at which the absorber operated resulted in
deflection of the absorber windows, these deflections were modelled
using ANSYS [42]. The uncertainty in the window deflection derived
from the model was 20%." to
"The pressure at which the absorber
operated resulted in deflection of the absorber windows. These
deflections were modelled using ANSYS [42], and the uncertainty in the
window deflection derived from this model was 20%."
OK

line 405: "The model showed..." to "The model shows..." match tense with "begin"
OK

line 411: "loose energy" to "lose energy"
OK

line 423: "of the of the vessel"!
OK

line 423: "Combined, the change in thickness of the absorber windows
on axis is 13 μm." I don't understand what's being combined. Should
this be "The change in the combined thicknesses of the absorber
windows on axis is 13 μm."?
OK

8 Summary
line 439: needs a sentence about the LH2.
OK

Somewhere (after acknowledgements?) there should be a Code
Availability statement along the lines of:
"The MAUS software used to reconstruct and analyse the MICE data is
available at https://doi.org/10.17633/rd.brunel.8337542. The analyses
presented here use MAUS version 3.2.0."
Possibly not strictly needed, but given that we have "MAUS v.3.2.0"
emblazoned on every plot...
OK. Added reference to DOI link.

References
[36] Capitalise MICE
OK

[37] Is this needed if it's part of [38]
OK

[41] Is this pp.421–423 of Proceedings of IPAC’10, Kyoto, Japan
(2010)? https://accelconf.web.cern.ch/IPAC10/papers/mopeb065.pdf
Added the URL in the bibliography since was not present in BibTex

[43] "Gridpp" to "GridPP" and "uk grid" to "UK Grid"
OK

6 Tracker
fig. 13: "central fibres of plane" to "central fibres of each plane"
OK

line 231: Does changing "particles" to "individual particles"
strengthen our point?
OK

line 300: "this was periodically recovered..." Is the "periodically"
appropriate?
OK. Dropped

line 302: "Monte Carlo simulation was used with realistic field and
beam conditions to..." to "Monte Carlo simulation with realistic field
and beam conditions was used to..."
OK

fig. 14: Caption should add something like "Each dot represents a
single data-taking run between 10 minutes and 3hrs long." I forget the
exact lower limit, for the upper the exact value isn't important but
needs to be representative.
OK. 10 minutes seems reasonable but need to check my code once get access back to Warwick's cluster.

fig. 15: Needs a meaningful caption!
OK

fig. 16: Needs a meaningful caption, and it's the Downstream tracker!
OK

line 320: "The position of the trackers along the beam line was taken
from the survey." Eh? I thought it was "inferred" at line 316. Either
this sentence is referring to the position of something else, or it's
a misleading duplicate and should be deleted.
OK. Deleted

line 326: "The position of each tracker along the beamline was
determined from the survey." Eh?, again. "An initial estimate for the
position of each tracker along the beamline had been inferred from the
survey." ?
OK

line 324: "position... was specified..." to "was described..."
OK

---

Paul Kyberd (on 5.5):¶

Line 13
comma before physical and after properties.
Comma after parameters can stat or not too taste
???

line 23 ... the beam is accelerated. It refers to the phase space
OK

line 24 The time
OK

line 28 no comma after the close bracket
OK

line 34 deleta "a repetition rate"
OK

l 35 repleace "with a rate of" with "at"
OK

l 35 "Pions crated in the interaction of the bema and target"
OK

l 45 no hyphen in coordinate - OUP and CUP
Ok

l 56 to measure - colon and them semi-colons to replace the commas
OK

Chris Rogers (on 5.5):¶

The author list checks out - it looks the same as the nature paper, except Paolo has added some updated "currently ats".
OK

References:
In general, please be consistent when reporting dates, either use (month, year) or (year)
OK

[5] Please reference the CERN yellow report and also put a date on
OK

[20], [35] Elsewhere you have used full journal name and month, year rather than JINST
OK

[17] vs [27], [32], elsewhere: use the same journal name for the same journal (full name or abbreviation)
OK

[40] Not sure, is it appropriate to put [accessed blah] for this one? Should you do that for other URLs? Up to you.
OK

Probably worth checking for similar issues in other references.
OK

Introduction:
I think you should mention frictional cooling. It is likely to come into production use at PSI in the next couple of years. There was a PRL paper published last year on it (lead author Angela Papa. I think Dan Kaplan is also an author).
OK

Line 48: "the beam, its evolution" -> "the beam and its evolution"
OK

Line 53: "the scintillating fibre trackers discussed in section 6" for consistency.
OK

Line 54: "7" -> "section 7"
OK

Line 60: why is 240 MeV/c relevant? I think you need to introduce in section 1, perhaps at line 39, a sentence like "Beams having muon central momenta between 140 and 240 MeV/c were used for ionisation cooling studies."
OK

Line 116: I found this sentence difficult to read. I think "The Delta t resolution, sigma_Deltat, will be given by sigma_Deltat = 2 sigma_t, assuming that...." would be easier. Note also the position of the commas.
OK

Fig. 6: I think the title should just be CkovA and CkovB if it is easy to change. Don't worry if it is fiddly.
OK

Line 219: "of 400 MeV/c, this maximised" -> of 400 MeV/c. This maximised"
OK

Line 254: produces -> produced.
OK

Line 256: The quality of a test statistic may be characterised -> The quality of this test statistic was characterised
OK

Line 257: "the fraction, alpha of" does not sit well with "the contamination, beta, the fraction of". I think it should be "the fraction of the muon sample that is rejected, alpha, and the fraction of the electron sample that is selected, beta."
OK

Line 275: "does not repeat" -> "did not repeat"
OK

Line 279: figure 12) -> figure 12.
OK

Line 328: "Overall the high track-finding efficiency was found to be
consistent with that introduced by the number of dead channels and did not introduce significant systematic uncertainties in analysis of the MICE data."
I don't think this is true. I would prefer for this sentence to be removed. I had to put in a correction for tracker inefficiency and for high amplitude bins it was quite significant (10 % IIRC). For the core bins it was a few %, which was significant compared to the effect we were trying to measure.
OK

Line 406: resolution of 0.1 K -> resolution of 0.1 K.
OK

Line 421: cause -> caused
OK

Line 426: I think this paragraph should be in past tense for consistency
OK

Line 454: "had to be" -> "was"
OK

Line 454: "internally, the" -> "internally. The"
OK

Line 493: "in presence of" -> "in the presence of"
OK

Line 494: "lithium hydrade"-> "lithium hydride"
OK