System Performance Paper Draft 2¶

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Review meeting will be on Wednesday 27th May at 14:30 BST. Zoom information below (if you can't get in, let Chris Rogers know)

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Notes¶

Present:

Ken Long
Chris Rogers
Paolo Franchini
Ludovico Tortora

We had a brief discussion. Paolo indicated that he had not yet finished editing the note. We looked at revised Ckov plots shown at the analysis workshop last week. We agreed that:

• Paolo would issue a new version of the MICE note on Wednesday 4th June
• We would attempt a meeting on Wednesday 11th June, subject to Alan's availability

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Open actions:¶

• Add a sentence and table . Not completed...
• Propose revised Ckov plots. In progress... PID is puzzling. Proposal: include only a 2D histogram for the NPE vs TOF01 and extract only the refractive indexes and the PE saturation yields. Remove thresholds calculations.
• Try merging section 6, 7 and 8. In progress... Joined the sections under a the very same section (e.g. sub-->subsub), nothing has done yet in term of rewriting.

First review meeting comments:¶

Add a sentence and table summarising the PID performance of each detector.
- in progress...

Remove statement promising "The integration of the instrumentation in a comprehensive diagnostic system will also be described." from abstract
- done

Add lH2 absorber to fig.1
- lH2 absorber inside the FC is in fig.19. Have referenced this. Can put a inset but would basically be fig.19.

Reduce level of detail on ToF readout to be consistent with other detectors
- trimmed TOF slabs description and readout

Propose revised Ckov plots
- in progress...

Ensure fig. 7, 9 and 10 are cohesive with section 4.
- point taken for the very last draft

Revise spelling of KLOE-lite.
- in "The MICE Muon Beam on ISIS and..." is “KLOE Light” (KL) and in "Pion contamination in the MICE muon beam" is KLOE-Light (KL) --> I will use KLOE-Light (KL)

Describe reason for worsening tracker efficiency in Dec 2017
- as per AB comment: "The variation in efficiency over time was primary due the loss of VLPC channels from moisture infiltration into the system and then partial recovery with drying."

Put helical and straight track efficiency plots on same scale.
- done

Try merging section 6, 7 and 8.
- in progress...

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Alan Bross comments:¶

AB_SPP_comments_2020-05-20.docx

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Ludovico Tortora comments:¶

Title : Performance of the MICE diagnostic systems > system or detectors
- system

34 : KL > preshower detector KL (first KL’s mention)
- "mounted in front of the KLOE-Light pre-shower detector..."

35 : two TOF stations > the first pair or couple of TOF stations (as fig. 4)
- "The time of flight between the first pair of TOF stations (figure 4) provided..."

39 : TOF detectors > TOF and KL detectors ( as cited in ref. 11)
- done

67 : Measurement of time traversal of a particle > Determination of time stamp of a particle
- done

68 : When a particle crossed …. > new line and 70. in succession
- done

146 : Add Reference : F. Ambrosino et. al., Calibration and performances of the KLOE
calorimeter, Nucl.Instrum.Meth. A598 (2009) 239–243. (as therein Ref. 11)
- done, was indeed missing a reference here

282 : significant proportion > significant fraction
- done

317 : unavoidable feature > unavoidable inaccuracy
- done

332 : overall detector performance > overall tracking performance
- done

335 : energy change on passing > energy change crossing
- done

369 : with a large uncertainty > with a ± 2÷3 cm uncertainty
- "with a 2--3\,cm uncertainty"

425 : the uncertainty in the density as (70.5 ± 0.08) kg/m3
to be checked because same value as
462 : corresponding to a liquid-hydrogen density of (70.5 ± 0.08) kg/m3 …. and confirmed in line 469
not sure about this comment: this is the density determined for the steady-state. Should we avoid to repeat this value three times in the text and just quote "the calculated liquid-hydrogen density"?

464 : various momenta > various nominal muon momenta
- done

and the same in Table 5 caption
- done

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Chris Rogers comments¶

(factual issues only)

General comment that you may encounter - there is not much "system" here; you have performance of individual bits, which are covered in other papers, but the combined performance (which I guess is the novelty) is not really covered well. Might be a criticism from the collaboration (or journal) that there is little original work.
- Agree. We can aim now for a collaboration wide review. If this is going to stop from submitting to a journal might be the end of it. Same if major comments from a journal would require a full PID analysis.

Line 36: "TOF stations can be used for momentum measurement" - no, when combined with the known distance between TOFs we can measure velocity. Momentum can only be inferred if we assume particle mass.
- "The time of flight between the first pair of TOF stations provided particle identification information and, assuming particles mass, can also be used to infer the momentum."

Line 65: "With 200 ps resolution, one reached near 100 % discrimination efficiency" - assuming we know the momentum; either by momentum selection in D2 or measurement in TKU.
- "With 200 ps resolution, together with momentum information, we reached near 100% discrimination efficiency"

Line 88: "A particle crossing a TOF station must have crossed 2 orthogonal slabs in the station’s 2 planes": it can hit 3 slabs (diagonal crossing)
Line 95: "They were matched if the times were within a 4 ns window" what if 3 signals within this window e.g. particles crossing into multiple slabs?
- Looking in the code (MICE0251 is offline) we can have multiple spacepoints (aka pixels) for each possible combination within the 4ns window, so this could be the case of a diagonal crossing with 2 space points, e.g. (x_0,y_0) (x_0,y_0+1). Shall we be more explicit in the text ("...at least 2 orthogonal slabs...")?

Line 107: "naive addition" I think you mean naive quadrature addition? i.e. ((0.114/2)**2 + 0.126/2)*2)**0.5 = 0.085 ... might be worth being explicit
- done

Line 108: "to contributions to the resolution of individual stations which cancel out in the slab ∆T measurement" what does this mean? What contributions are you referring to?
- quite confusing, I think was meant to comment on the result of the the quadrature addition; removed because is not adding any further information (∆T01 > quad_sum(∆T0 + ∆T1))

Fig. 4: the electron peak fit is too far into the tails - so the peak is not well fitted. Best to reduce the fit range on fig. 4 electron peak.
- done

Fig. 6: As JHC commented at the analysis meeting, really we should be using TOF or beta to measure the threshold (i.e. x-axis of fig. 6) and deducing the associated particle momentum. It means that errors from wrong PID go away. Sorry, I should have thought of this!
- in progress

Comparing fig. 8 vs Fig. 9 is difficult. I think, given the KL is essentially a PID detector, slicing as in Fig. 9 makes more sense? At least the two plots should be sliced by the same variable be it PID or momentum.
- Shall we remove fig.8 if not adding much information in term of PID? I do not see how it could be sliced in momentum if showing different momenta *

line 183: "Each even bar was rotated by 180 with respect to the odd one." I figured out what you meant eventually - but it wasn't clear which axis of rotation you referred to
- cut it out since is confusing here but clear in the caption relative to the figure "cross section of the arrangement of 3 bars"

line 223: "If hits were produced in the detector, space points were reconstructed 98.56±0.06 % of the times" does this mean 1.4 % of events produce hits but no space points at all?
- a missed hit in X or Y plane of a X-Y module does not allow the reconstruction of the space point within the module (Francois' thesis), so I assume 1.4% of events do not produce hits in both the planes

line 224: "muons that decay between TOF2 and EMR" what is the probability of a muon decaying in this distance? Is it as high as suggested, 1.4 ?
- I assume 1.4 accounts the detector inefficiency and the muons' missing hits

Line 293 "oblique fibres" shouldn't this be oblique channels?
- done

Could you please specify the TOF cut?
- single TOF0/1 event + TOF01 cut

Was there any other cut e.g. a requirement on central pixels of TOF?
- not that I am aware of from this C. Hunt's analysis

I'm not sure I understand the cuts - do you count events with multiple space points as inefficiency? Or do you ignore these events (remove them from the analysis completely?)
- I ignore those events. I recall this has been already discussed reminding myself changes done on the code.
"The selection of events used in the analysis included two more constraints, as generally required in most of the analysis:"

Is there a plot or figure here? You don't reference anything...
- True

First paragraph: probably we should mention that we have no resolution on z-position or rotation about z-axis
- "...while we do not have resolution on the position along the beam axis or rotation about it."

Second paragraph: We should mention that TOFs can be tied directly into the survey (they are visible)
- "The surveyed location of the TOFs was used as the reference..."

line 364: What does "Multiple scattering in the beam line would not allow formed alignment on
single-particle basis" mean?
- is needed a statistical ensemble, in order to extract residuals

line 377: "The selection criteria defined above remove this effect." where are they defined?
- Got lost from some longer version. "A fiducial cut is applied to the upstream sample in order to remove this effect."

line 415: "The boiling point of hydrogen at 1.085 Bar is 20.511 K (figure 20)" not sure whether we are supposed to deduce the boiling point from the figure? I thought fig. 20 assumes the boiling point?
- Correct. Is misleading referencing fig.20 here? have postponed it after the error discussion.

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