2015-09-01 Survey¶

Present:

Tony Millington (ISIS Survey Team)
Jason Tarrant (MICE Integration Engineer)
Chris Rogers (MICE Physics coordinator)

Meeting to discuss recent survey results and comparison with John Palin survey; January 9th 2015

• Datums of new survey fits with datums of John Palin survey to ~0.5 mm
  • (Datums are wall mounted permanent survey points)
• ISIS surveyors have defined a new coordinate system, defined by
  • Line through quad centres. This was found by constructing a jig that fits in quad bore, with survey probe mounted; and surveying the jig in each of the quad centres; and finding a line through the centres (good to ~0.5 mm)
  • Brass plate under D2
  • Uniquely defines x-z plane; defines y axis
  • Consistent with ISIS tooling height
  • Nearly the same as John Palin survey; correct to ~ cms
  • Closer to Colin Croxford survey (2006)
• Jason Tarrant noted that we need resurvey of TOF1 and EMR
• Rogers described the survey procedure
• Rogers requested document that would describe a procedure enabling a new surveyor to rebuild the coordinate system a priori (i.e. describing jig method)
• Rogers requests, for new surveys
  • Description of how the survey was done
  • Description of survey points
• See also
  • MICE Note 216 Colin Croxford survey
  • MICE Note 424 John Palin survey
  • MICE Note 436 John Palin survey
  • Original discussion with John Palin :
    • 25th March 2013
    • 9th April 2013

• Rogers received survey report on 13th January, some long email chain reproduced below but in short...
  • z-axis is defined by vector with direction given by gravity, as defined by the Laser tracker inclination sensor, and intersecting the M1 point under the dipoles
  • x-axis is defined by vector that intersects the z-axis and the centre of Q9 and is perpendicular to the z-axis; Q9 centre defined by the positioning jig
  • y-axis is defined as the perpendicular to these two
• Rogers requested revised survey report to clarify these points.

Long email chain:

On 27/01/15 12:46, Millington, Tony (STFC,RAL,ISIS) wrote:
> The vertical axis (z) is to gravity, as defined by the Laser tracker inclination sensor.
> 
> Cheers
> 
> Tony
> 
> 
> -----Original Message-----
> From: Rogers, Chris (STFC,RAL,AST)
> Sent: 27 January 2015 12:30
> To: Millington, Tony (STFC,RAL,ISIS)
> Subject: Re: MICE Surveys
> 
> I don't understand then, how do you define the vertical axis?
> 
> Chris
> 
> On 27/01/15 12:21, Millington, Tony (STFC,RAL,ISIS) wrote:
>> Chris
>>
>> Yes they are,  but the x axis is horizontal and defined using the horizontal (ie x,y) coordinates for M1 and Q9.
>>
>> Hope that helps.
>>
>> Tony
>>
>>
>> -----Original Message-----
>> From: Rogers, Chris (STFC,RAL,AST)
>> Sent: 27 January 2015 12:14
>> To: Millington, Tony (STFC,RAL,ISIS)
>> Subject: Re: MICE Surveys
>>
>> On 27/01/15 11:22, Millington, Tony (STFC,RAL,ISIS) wrote:
>>> Hi Chris
>>>
>>> Don't worry about being pedantic - what seems obvious from a survey point of view isn't always obvious from a different viewpoint, so it certainly doesn't hurt to point out what needs to be clearer!
>>>
>>> * the x axis "MICE Beamline" is the best fit line through the quadrupole centres;  nearly, the X axis is a line from M1 to the measured centre of Q9 quadrupole, this being the longest line we can measure.
>>
>> Let me be thick for a moment - isn't M1 at floor level; and Q9 centre at beam level?
>>
>> Cheers,
>> Chris
>>
>>> * the x-z plane is defined by the plane containing the MICE beamline
>>> and the "M1" point described above; yes
>>> * the z axis is defined by a line in the x-z plane intersecting "M1" 
>>> and the x axis, perpendicular to the x axis; yes
>>> * the y axis is defined by a line intersecting the x axis and z axis
>>> and perpendicular to both; yes
>>> * your coordinate system is right-handed. Yes
>>>
>>> Z= 0 is at 603 below ISIS tooling height, floor level varies from
>>> approx. -1210 to -1900 (depending on which section of floor) The MICE beam height is 465.65 as a mean of the measured magnet centres, from what I can find in the original documentation and design notes the beam was intended to be at 138mm below tooling height.
>>>
>>> I think that answers your questions - please let me know if you need anything else.
>>>
>>> Cheers
>>>
>>> Tony
>>>
>>>
>>> -----Original Message-----
>>> From: Rogers, Chris (STFC,RAL,AST)
>>> Sent: 23 January 2015 17:19
>>> To: Millington, Tony (STFC,RAL,ISIS); Tarrant, Jason (STFC,RAL,TECH)
>>> Subject: Re: MICE Surveys
>>>
>>> Hi Tony,
>>> Thanks a lot for this, this report looks great!
>>>
>>> Can I ask for a clarification. You write in MICE Hall Re-Survey:
>>>
>>> "The Brass scribed plate located beneath Magnet D2 has been surveyed (Point 'M1'), this point represents the origin of the MICE Beamline." 
>>>
>>> My understanding is that:
>>> * the x axis "MICE Beamline" is the best fit line through the
>>> quadrupole centres;
>>> * the x-z plane is defined by the plane containing the MICE beamline
>>> and the "M1" point described above;
>>> * the z axis is defined by a line in the x-z plane intersecting "M1" 
>>> and the x axis, perpendicular to the x axis;
>>> * the y axis is defined by a line intersecting the x axis and z axis
>>> and perpendicular to both;
>>> * your coordinate system is right-handed.
>>>
>>> Apologies for being pedantic, I am a computer programmer so I like these things uniquely defined! Or maybe I misunderstood from our meeting? I spoke to Henry and he indicated that the x-axis (z=0) is at floor level, so perhaps I misunderstood?
>>>
>>> Cheers,
>>> Chris
>>>
>>> On 13/01/15 12:36, Millington, Tony (STFC,RAL,ISIS) wrote:
>>>> Jason/Chris
>>>>
>>>> I've attached completed survey reports and files for the MICE Hall
>>>> resurvey and the Proton Absorber survey.
>>>>
>>>> Hopefully the format(s) include all the info and data you need -
>>>> please give me a shout if there is anything missing or you need clarification.
>>>>
>>>> Kind regards
>>>>
>>>> Tony
>>>>
>>>