Tracker mechanics for the Pilot Run - Marco Incagli - INFN Pisa Carlo Ferrari, Maurizio Massa, Andrea Moggi (PI) Giovanni Cantatore (TS) 18 ...
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Tracker mechanics
for the Pilot Run
Marco Incagli – INFN Pisa
Carlo Ferrari, Maurizio Massa, Andrea Moggi (PI)
Giovanni Cantatore (TS)
18 September 2020
1 18/09/2020 Marco Incagli - INFN Pisa
Pilot run Fall 2021 • Muone has been allocated 20 days beam time (possibly) Q4 2021 • We have ~1 year to build and integrate the tracker system 2 18/09/2020 Marco Incagli - INFN Pisa
Tracking system • 3 tracking stations; first one with no target 3 18/09/2020 Marco Incagli - INFN Pisa
Tracker station mechanical design
Beryllium (?) target
(u,v) layer
• The “tilt angle” helps in improving the hit
resolution, but it may create problems in
the fitting stage
• A final decision has not yet been taken; it
has an impact on the details of the
mechanics, but not on the general layout
• I’ll show the version with the maximum
(x,y) tilted modules
tilt of 268 mrad
4 18/09/2020 Marco Incagli - INFN Pisa
The MACRO tilt
• By rotating the modules, the hit finding precision improves by
~20%, as the “shower” inside the Silicon sensor is partly
shared among two adjacent strips
• resolution of a 2S sensor
measured at test beam
• it improves from ~27 µm
to ~22 µm for a sensor
rotation of ~15o
• (information provided by
Duccio Abbaneo)
5 18/09/2020 Marco Incagli - INFN Pisa
The MICRO tilt
• The strips of the two sensors of a Pt2S module are aligned, between
the sensors, and have a pitch of 90 µm
• If one could “stagger” them by half a pitch, then resolution would
(theoretical!) improve by a factor 2
• This Effective Staggering (ES) can be obtained by rotating the module
2S sensor
1 2
25 mrad
Dy = 90 µm
ES = 2.5
ES = 0.5 ES = 1.5
Dz = 1800 µm
Drawing NOT to scale!
6 18/09/2020 Marco Incagli - INFN Pisa
Layers 1 and 3
• Modules in layers 1 and 3 are tilted by 268 mrad (layer 2 is
NOT tilted)
• Each module has to be tilted around an axis parallel to the
strip direction in order to get the “effective staggering”
TOP SIDE
VIEW VIEW
x y
x
z
z
y
7 18/09/2020 Marco Incagli - INFN Pisa
Aluminum mock-up • All parts have been designed • Two Al mockups will be constructed in Pisa and Trieste 8 18/09/2020 Marco Incagli - INFN Pisa
Tracker station mechanical design
Beryllium (?) target
(u,v) layer
hydraulic for cooling system
(x,y) tilted modules
9 18/09/2020 Marco Incagli - INFN Pisa
Stations for experiment in INVAR • the request on the module stability on the z direction (along the beam) is dz
Support table and alignment system
• Each tracker station is mounted on an optical table through a
system of actuators to center the beam (~130cm) and allow
for the precise positioning (details on this later on)
• Three points of support
• Linear stages:
– XY upstream
– XY and X downstream
Max axial load 700 N
11 18/09/2020 Marco Incagli - INFN PisaHAM : Holographic Alignment Module 12 18/09/2020 Marco Incagli - INFN Pisa
HAM : Holographic Alignment Module 13 18/09/2020 Marco Incagli - INFN Pisa
HAM : Holographic Alignment Module 14 18/09/2020 Marco Incagli - INFN Pisa
The box, or “tracker enclosure”
• The tracker structure is inserted into an enclosure which
provides the connections to the services, the light tightness
and it thermally isolates the tracker
• Two patch panels per
module with eletrical
and optical
connections (top
one) and with
hydraulic
feedthroughs (bottom
panel)
15 18/09/2020 Marco Incagli - INFN PisaThe tracker with the box on the table • side and top panels can be removed to access the modules and for the general survey 16 18/09/2020 Marco Incagli - INFN Pisa
Temperature stability
• the temperature, in the hall, varies from 10 to 30 degrees,
with daily variations of 6 degrees
30
25
20
15
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May
17 18/09/2020 Marco Incagli - INFN PisaCooling system and dry air flow
• The modules are cooled with a water-glycole liquid flowing at
~18C
• The support structure is also cooled by the same liquid
– the module position has to be “stable within 10 µm”
– this requires a temperature stability of ±2C (the goal is ±1C)
• Under discussion with Cern (visit to the site on Thursday Sep,
24) is the possibility of having a “tent” mounted around the
detector with a simple (and cheap) A/C system to be used as
thermal buffer
• In current design, the possibility of flowing dry air at T=18C,
to keep air density constant, is also foreseen
18 18/09/2020 Marco Incagli - INFN PisaSistema di controllo della T
§ La temperatura della struttura in Invar deve essere mantenuta in un range
di ± 2 °C se si vuole contenere la dilatazione termica entro 10 mm.
§ I moduli tracker Pt2s dissipano 5 W ciascuno
§ Ogni stazione prevede inoltre un ingresso di aria secca, per mantenere la
sovrappressione ed eliminare l’umidità dal percorso del fascio. Tale flusso
deve essere termalizzato a 18°C.
Il controllo della T avviene mediante un chiller Julabo, mod. CP-1001F (10 kE
circa):
Gamma temperatura di lavoro: -38 ... +100 °C
Stabilità temperatura: ±0.03 °C
Capacità refrigerante a 20 °C: 1 kW
Capacità pompa portata: 8 ... 27 l/min
Capacità pompa flusso pressione: 0.1 ... 0.7 bar
Apertura vasca utilizzabile (LxLxA): 35 x 41 / 30 cm
19 24/06/2020 Muone tracker mechanicsSistema di controllo della T
Il flusso di acqua termostatata del chiller (< 27 l/min) viene diviso tra i
seguenti circuiti di raffreddamento:
§ Calorimetro
§ Strutture stazioni tracker (condotto in rame in contatto termico con
base e spalle di ogni stazione)
§ Circuiti di raffreddamento dei moduli Pt2s (18 moduli, 90 W in totale)
§ Scambiatore di calore (per termostatare il flusso di aria secca)
Scambiatore di calore (600 Euro + IVA):
Dimensioni: 309.6 x 112 x 24.1 mm
Flusso: < 50 l/sec
Superficie di scambio: 30 m² , Pressioni max: 30 bar
Da aggiungere:
Tubazioni aria/acqua, derivazioni, tubi isolante in neoprene, sensori: T,
P (200 Euro) e flusso (600 Euro)
20 24/06/2020 Muone tracker mechanicsCustom alignment system
• Based on linear
stages
• Simple design
• Motorized control
• Software provided
(interface to the slow
control needed)
Max axial load 700 N
21 24/06/2020 Muone tracker mechanicsCustom alignment system
• 5 attuatori per stazione
• Offerta IGUS: 3600 Euro +
IVA / stazione (actuators+step
motor NEMA 23)
• Da aggiungere: y
• Staffe di supporto
• Giunti sferici (v. oltre) x
• Cavi per motori e sensori
fine corsa
• Feedthroughs per Patch
panel
22 24/06/2020 Muone tracker mechanicsKinematic aligment Different thermal expansion coefficients 23 24/06/2020 Muone tracker mechanics
Upstream support
XY linear stages upstream
The sphere allows rotation
Spherical joint The translation is prevented
24 24/06/2020 Muone tracker mechanicsDownstream supports 25 24/06/2020 Muone tracker mechanics
Station aligment
1) Raw alignment to the beam
2) Leveling the station w/o beam
3) Beam ON: data acquisition & analysis
4) Center of the layer upstream:
Module X and Y of upstream layer will
guide linear stages X and Y respectively
5) Center of the layer downstream as
above y
6) Rotation: move the whole station along
x
X (and Y) and adjust the X stage
downsteam accordingly
Single motor step is 5 µm
7) Repeat from 3)
8) Position survey from CERN
(temperature issue)
26 24/06/2020 Muone tracker mechanicsPt2s: alignment and curvature
• The fine alignement of the 6 modules (12 sensors) within
the station is done with straight muons
• The maximum shift of the linear actuators can be chosen
at will, whithin limits. Current default value is 30 mm
• The maximum tilt angle (X and Y axes) will be:
(travel distance [mm])*2 mRad
30 mm
= 60mrad in current config.
• The step angle will be 5 µRad
30 mm
• La settimana prossima (mercoledi’ 23/09) abbiamo un
incontro con Marco Musich, esperto di allineamento in
CMS, per perfezionare la procedura
27 24/06/2020 Muone tracker mechanicsConclusions • Tracker design is ready • Need to finalize configuration (very soon!) • Two Al mock-ups built next two months • Order of INVAR possibly before the end of the year • Thermal environment (=”tent”) to be defined at Cern • Other details have to be finalized, but the general scheme of the tracker mechanics, thermal and alignment system is in an advanced state • Funding request for 2021: next slide! 28 18/09/2020 Marco Incagli - INFN Pisa
Richieste 2021
PISA
TRIESTE
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