Central Tracker review Micromegas central forward tracker RD

Central Tracker review Micromegas central & forward tracker Ø R&D and prototypes Ø CAD implantation study Ø Interfaces Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 1

Clas 12 R&D on detectors • CLAS 12 R&D and prototype in 2009 – – – Bulk in high magnetic field at Jlab Spark rate with alpha source Spark rate with muon and hadron beam at CERN Resistive kapton film prototype Development on curved drift with X tile prototype Cosmic bench for future prototypes MIP’s characterization • CLAS 12 R&D and prototype in 2010 – – – Spark rate with alpha source at 1. 5 Tesla Forward prototype (thin flat, segmented mesh) Y tile prototype Beam at CERN (forward, gas studies, …) Beam test at Jlab ? Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 2

Micromegas tracker: CAD study

CLAS 12 Micromegas tracker CAD Study • The CAD study for MM implantation was done in 2007 for feasibility • The study was based on successful technical solutions validated by experiments before 2007 • This study was done on a mixed solution for the central tracker – two double silicon tracker layers at low radius and three double Micromegas layers at higher radius. • The forward tracker was based on Micromegas solution with three double layers. Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 4

Central tracker mixed solution: Si +µM • Symbiosis between Si and µM: to be studied: – Mechanics • Common tracker structure • Common alignment system • Localization in space for minimum dead zone and maximum spatial resolution • Common connectors and/or flex cables – Electronics • Common ASIC • Common Concentrator • Common DAQ – Collaboration on various topics mentioned above during the development phase. Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 5

Central Tracker CAD study Forward tracker Magnet Central front end electronics Forward front end electronics Micromegas central tracker Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 6

Tracker dimension Radius (mm) length (mm) Circumference (mm) Surface (m 2) X strips number d 1 X 110 255. 6 691 0. 18 2082 d 1 Y 120 255. 6 754 0. 19 d 2 X 170 383. 2 1068 0. 41 d 2 Y 180 383. 2 1131 0. 43 d 3 X 230 509 1445 0. 74 d 3 Y 240 509 1508 0. 77 Total surface : 2. 72 Detector Y strips number 2556 3330 3831 4575 5088 9987 11475 • Each layer of detection is composed of two MM detectors with X and Y strips at 90°. The usability of a single X-Y detection PCB board will be studied in 2009 • The bulk maximum size is 600 mm x 800 mm. • The cylinders where divided in three sectors to match dead zone Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 7

Demonstrator tile: detector structure • Each bulk PCB is mechanically fixed to a light structure which sets its curvature. The shape and material will be studied for low material budget. The mylar drift window is glued on the bulk active area. Detector structure with bulk Demonstrator picture Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 8

CAD study: tile and dead zone • In this first study we have a rather large dead zone of 30 mm between adjacent tile active area. Further studies will be done to reduce the dead zone and match Si (tbc). • The no dead zone configuration imply overlap of tiles (complex structure) Flex connection Active area Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 9

CAD study: central structure • The central structure will hold the bulk tiles on several radii for the barrel and at several positions for the forward disk. • Each tile will be extractable from the structure independently from the others. • The whole structure with its detectors and electronics will be extractable from the magnet through a slide rail system. Location for electronic Si tracker Location for disk bulk (forward) HT cable and gas (volume representation) Location for curved bulk Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 10

CAD study: central structure with µm tiles • The electronics box will be hooked to the central strucrure allowing: – Box dismounting – Single flex disconnection – FE and concentrator card access. Flex forward tracker Electronic FE and concentrator Forward tracker (magenta) Central tracker (blue) Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 11

CAD study: central structure- cut view • The cylinder layers are divided in three sectors in the 2007 study. Barrel tracker (blue) Dead zone between sectors Stéphan AUNE Gas pipe distribution (violet) CLAS 12/Central Tracker review. Saclay 12/09 12

CAD study: Forward Micromegas Tracker • The forward tracker consisted in three layers of flat disks. Each disk is two faced with U strips on one side and V strips at 60° on the other side. Each disk side is divided into 3 sectors (6 in the most recent simulation). • The disks are located just after the cylindrical tracker every 15 mm. The sectors of each twin disk are not aligned to avoid dead zones (tbc). Central tracker Stéphan AUNE FMT : 6 disks piled up CLAS 12/Central Tracker review. Saclay 12/09 13

CAD study: FMT, dimension Internal diameter (mm) Disk Total 25 External diameter (mm) 250 Surface pitch (m 2) (micron) 0. 19 Number of strips 300 1. 17 1500 9000 • To obtain a thin flat Micromegas, the PCB has to be set on a support. We first considered to use the COMPASS technique using a 3 mm thick Nomex honeycomb panel on which the 100 µm thick PCB is glued and the detector stays flat. • The exact cutting of the disk is not yet definied Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 14

CAD study: flex for FE readout • In order to located the front end electronic at the rear of the tracker we will use 800 mm long flex. • The flex will be going between the CTOF and the last central tracker layer. FMT flex Central Si detector Central µm detector Stéphan AUNE 5° cone from target Forward µm detectors CLAS 12/Central Tracker review. Saclay 12/09 15

CAD study: FMT mesh segmentation • In order to reduce dead time due to discharges when there is high occupancy at low radii, the mesh will be divided in several (2 in this study) independents areas. While sparking in inner region, the detector will still be operating in the outer region. An R&D on mesh segmentation will be done in 2009 -2010 to study the minimization of the dead area between the two mesh surfaces and to validate the concept on a prototype in beam ( dead zone < 1 mm). Active area Mesh segmentation Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 16

CLAS 12 CT internal interfaces • We need the space allocation for each sub system to go further in CAD studies – Can be done when final choice are made (i. e. MM for barrel) and constrains of each sub system studied together. • We need a Coordinator for the CT: – Interface can be worked with neighbor and proposed to CTC – Common 3 D CAD model updated every 6 month – Assembly plan – Budget: weight, heat load, power consumption, … – CT meeting every year for a Preliminary Design Review in 2011 Stéphan AUNE CLAS 12/Central Tracker review. Saclay 12/09 17

CT a Russian doll integration Limited space budget: crowded inside !! MM barrel MM Forward Cryo target Si barrel • Interfaces • Mechanical • Electrical • Thermal • Accessibility • detectors • Electronics • Servitude • Gas • HT • Signal, …/… Ctof Neutron detector Magnet Stéphan AUNE HTTC CLAS 12/Central Tracker review. Saclay 12/09 18

MM electronic location • The maximum distance between MM detectors and the front end electronics is around 1 meter. two options: – In the tube: we fit in the fixation tube (around SVT elec. ? ) • Uneasy fixation and access, cooling needed, open tube ? – Outside the tube: we fit around the fixation tube • Longer distance to detector, easy fixation and access, hole in tube, interface with light guide lines. In tube Outside Stéphan AUNE barrel elc. Forward elc. CLAS 12/Central Tracker review. Saclay 12/09 19